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Quantitative evaluation of mechanical damage to fresh fruits
Abstract
Fresh fruits are very susceptible to mechanical damage during harvesting, packaging and transport, which can result in a substantial reduction in quality. Ideally, such damage would be minimized through improved understanding of the mechanisms. If damage occurs, economic losses might be minimized by grading affected fruits, based on the severity of damage, into those that need more than minimal further processing and those that do not. In either case, an objective and quantitative evaluation of the degree of mechanical damage is required. However, this is still far from being realized and remains an important challenge of past and proposed research in food safety.
This review concerns the quantitative evaluation of mechanical damage to fresh fruits. Firstly, the sources of damage to fresh fruits during mechanical handling are summarized. The mechanisms are described in detail. Existing quantitative assessments characterizing surface and internal mechanical damage and its prediction are then reviewed. Finally, future research directions are discussed. The main challenge in evaluating mechanical damage to fresh fruit objectively is to develop a method to assess accurately the extent of internal damage to fruits caused by excessive external forces.
... Harker (2009) reported that cosmetic damage in fruit was a more important barrier to purchase than price. Fruit without bruises or abrasions has a better appearance than bruised or abraded fruit, which leads to higher perceived quality and marketability values (Sablani, Opara, and Al-Balushi 2006;Li and Thomas 2014;Opara and Pathare 2014). Unfortunately, most fruit is sensitive to mechanical damage throughout the postharvest supply chain. ...
... During cell failure, the membranes disintegrate and the resulting de-compartmentalization may cause the phenolic substrates to merge with the polyphenol oxidases, which are normally located in the plastids. This results in browning (Li and Thomas 2014). Other processes that have been associated with mechanical damage are cell membrane leakage, enzyme activity, and cell wall constituent losses (Zhou et al. 2015). ...
... Once damage occurs, it is necessary to measure the damage degree objectively and quantitatively in order to grade the damaged fruit and calculate postharvest fruit losses, thereby minimizing economic losses. Currently, the damage detection of fruit is typically based on direct methods, such as manual evaluation and optical detection, and some reviews have been published in this area (Li and Thomas 2014;Opara and Pathare 2014). Besides direct measurement, mechanical damage may induce physiochemical responses in fruit, resulting in deterioration of fruit quality. ...
Mechanical damage of fresh fruit occurs throughout the postharvest supply chain leading to poor consumer acceptance and marketability. In this review, the mechanisms of damage development are discussed first. Mathematical modeling provides advanced ways to describe and predict the deformation of fruit with arbitrary geometry, which is important to understand their mechanical responses to external forces. Also, the effects of damage at the cellular and molecular levels are discussed as this provides insight into fruit physiological responses to damage. Next, direct measurement methods for damage including manual evaluation, optical detection, magnetic resonance imaging, and X-ray computed tomography are examined, as well as indirect methods based on physiochemical indexes. Also, methods to measure fruit susceptibility to mechanical damage based on the bruise threshold and the amount of damage per unit of impact energy are reviewed. Further, commonly used external and interior packaging and their applications in reducing damage are summarized, and a recent biomimetic approach for designing novel lightweight packaging inspired by the fruit pericarp. Finally, future research directions are provided.
• HIGHLIGHTS
• Mathematical modeling has been increasingly used to calculate damage to fruit.
• Cell and molecular mechanisms response to fruit damage is an under-explored area.
• Susceptibility measurement of different mechanical forces has received attention.
• Customized design of reusable and biodegradable packaging is a hot topic of research.
... Damage can occur during picking in the land, the distribution process to traders and consumers, and the storage process in the supply chain (La Scalia et al., 2016;Kelly et al., 2019;Ha et al., 2020). Bruised damage can cause accelerated damage to the whole fruit during subsequent handling (Li and Thomas, 2014). Many fruits with seemingly minor damage during harvest are then discarded by traders which results in waste and can affect economic benefits for farmers and traders (Yan et al., 2019). ...
... Fruit that has been damaged is sold at a cheap selling price. Li and Thomas (2014) reported that fruit tissue damage resulted in price reductions of up to 50%. An effort to minimize the damage to mass tissue in the fruit is an important thing to do in order to maintain the quality and efficiency of agricultural products. ...
... However, compression from the direction of the horizontal direction of the mechanical response only results from the structure of the fruit. These results were in agreement with those reported by Li et al. (2014) in which the compression from the horizontal direction only provides a mechanical response from the dense mass of biomaterial tissue as a result of which the fruit cell structure becomes weak. ...
Strawberries have very thin skin that is prone to damage during post-harvest handling. The strength of this fruit mass tissue has a difference between vertical and horizontal directions. Therefore, this study aimed to compare the strength of the strawberry mass tissue between vertical and horizontal directions using a compressive test at different speeds and compressibility levels. The research was conducted by placing a load on the sample from the vertical and horizontal directions. The variations in compression speed were 2, 4, and 6 mm/s, and the compressibility levels were 6, 12, 18, 24, and 30%, respectively. The results showed that the compacting from the vertical direction obtained a combined mechanical response between the fruit structure and mass tissue cells, while from the horizontal direction the mechanical response was only obtained from the fruit structure. Along with the duration of the compacting, mass tissue damage has started to occur. In this phase, the fruit cells begin to break down in the skin causing the mass tissue damage to decrease. The results of this study can be used to develop a more efficient and effective packaging model for strawberries that has never been disclosed before.
... Quality is defined as the combination of attributes that make food products desirable for consumption as human food (Opara et al., 2009). The demand for fresh produce has increased significantly in recent decades due to rising consumer trends towards healthy food, eating out, and consumption of minimally processed food (Li & Thomas, 2014). Within ten years, worldwide production of fruits has risen dramatically by 20.76% from 2008 to 2018, and the same trend was with vegetables which increased in the same period by 21.50% (FAOSTAT, 2020). ...
... Extending the length and complexity of the postharvest supply chain (Fig. 1) can make fresh produce susceptible to mechanical damage which results in degradation of quality and quantity . These losses in quality typically occur due to poor harvesting techniques, handling, storage, packaging, and transport facilities (Li & Thomas, 2014). Mechanical damage to agricultural commodities is one of the main issues in the harvest and postharvest supply chain, leading to significant economic and market value losses that are attributed to a shelf-life reduction (Hussein, Fawole, & Opara, 2019a, 2019b. ...
... Impact force on fresh commodity can result from many sources including vibration during transport, unexpected drop of the produce from a certain height, and an inadequately cushioned surface of packed produce during handling and transportation (Fadiji et al., 2016;Li et al., 2010;Pathare and Al-Dairi, 2022). The impact external damage on the produce are bruises or cracks on the surface (Li & Thomas, 2014;, which reduce the quality of produce (Kitthawee et al., 2011) and is apparent within a short duration (Eissa et al., 2012). Impact forces can alter the quality of fresh produce, like weight, firmness , respiration rate (Hussein et al., 2019a(Hussein et al., , 2019b, peel electrolyte leakage (PEL), color, and enzymatic activities (Hussein et al., 2019a(Hussein et al., , 2019b. ...
Background
Incidence of postharvest losses in the fresh produce value chain is a worldwide concern facing food security and sustainability. Postharvest losses can occur along the supply chain stages such as harvesting, storing, handling, packaging, transporting, and marketing. Mechanical damage caused by vibration is one of the most common quality challenges to fresh produce during transit.
Scope and approach
Mechanical damage of fresh produce can cause considerable economic losses by reducing quality and can result in severe food safety concerns. Understanding the factors affecting fresh produce damage during transportation is significant in developing strategies for reducing postharvest losses. We review transport as an essential component in the postharvest supply chain and critically discuss the adverse effect on fresh produce, mainly due to vibration.
Key findings and conclusions
The experimental approaches applied to measure the vibration levels during transport of fresh produce are presented. Factors influencing the vibration level discussed herein include surface condition, vehicle speed, vibration duration, vibration direction, packaging unit, etc. A comprehensive discussion on the effects of packing unit type and surface of packaging material, location of the package on the vehicle, and height of the package in a stack on the vibration level is presented. Vibration during transportation is difficult to avoid; however, applying good management practices like improving the refrigeration system, utilization of appropriate packaging, and incorporating suitable cushioning materials can reduce produce damage during transit. Overall, careful selection of better solutions to this critical issue can help to reduce fresh produce susceptibility to vibration damage during road transport and thereby reduce incidence of postharvest losses of fresh commodities.
... Sin duda alguna, este daño puede causar considerables pérdidas poscosecha y económicas, reducir la calidad del producto y resultar en serios A B problemas de seguridad alimentaria. Por tanto, comprender los factores que influyen en la susceptibilidad o resistencia de los productos a los hematomas es importante para desarrollar estrategias para reducir el problema (Hessein, Amos-Fawole y Linus- Opara, 2018) Desde otro punto de vista, el daño por magulladuras es el resultado de la acción de una fuerza externa excesiva sobre la superficie de la fruta u hortaliza durante el impacto contra un cuerpo rígido o de un rubro contra otro rubro (Li y Thomas, 2014;Stropek y Galocki, 2015). La evidencia física de hematomas es el resultado de la rotura celular (Schoorl y Holt, 1983), que resulta del estrés y la distorsión de las células individuales (Ruiz-Altisent y Moreda, 2011). ...
... Cuando la recolección no se lleva a cabo con el suficiente cuidado y atención se le puede ocasionar daños al cultivo. Por ejemplo, la recolección manual puede causar daños por compresión cuando las fuerzas de agarre que rodean la fruta superan el umbral de falla del tejido (Li y Thomas, 2014). Por otra parte, un mal diseño de las líneas de acondicionamiento y los procesos a los que se someten las frutas y hortalizas durante su paso por todas las operaciones de acondicionamiento pueden provocar alteraciones en la calidad de los rubros que se manifiestan de inmediato o durante su vida comercial. ...
RESUMEN
Las frutas y hortalizas siempre han sido populares entre los consumidores debido a que son una fuente notable de micronutrientes, fibras, vitaminas, compuestos bioactivos y antioxidantes, que las hacen muy recomendable como dieta saludable debido numerosos beneficios nutricionales, no obstante, son muy susceptibles a los daños mecánicos, los cuales pueden provocar una reducción de la vida útil del vegetal. Esta investigación tiene como objetivo revisar preliminarmente el conocimiento disponible sobre los principales aspectos relacionados con daños mecánicos en frutas y hortalizas durante la manipulación. Los datos se recopilaron de estudios calificados de bases de datos (como Google Académico, Science Direct y otras plataformas web), se estudiaron y resumieron. Se revisaron los daños mecánicos por golpes o magulladuras detallando los parámetros que caracterizan el daño superficial e interno. Así mismo, se analizaron los factores influyentes en la incidencia y gravedad de los daños por abrasión y cortes en los vegetales mencionados. El resultado de la búsqueda bibliográfica evidenció que los daños mecánicos se pueden manifestar como magulladuras, abrasión, deformación, cortes, punciones, fisuras o fracturas, por efecto de compresión, impacto o vibración e inducen la pérdida de agua e incrementa la actividad respiratoria y por tanto la velocidad de deterioro, causando pérdidas significativas de estos productos.
Palabras Clave: daño mecánico, magulladura, abrasión, vegetales
... The lack of suitable non-destructive instrumentation prevents the development of accurate numerical models (Liu et al., 2017) that could potentially be utilized to optimize areas where the greatest amount of postharvest stress occurs (Milne & Steyn, 2021). The impact of vibration and large amplitude accelerations (Steyn et al., 2011;Pretorius & Steyn, 2012) alongside interfacial stresses (Pretorius & Steyn, 2019;Li & Thomas, 2014;Stopa et al., 2014) associated with poor riding quality of road infrastructure (Ruiz-Altisent & Ortiz-Canavate, 1992) on tomatoes, are known to reduce the shelf-life markedly (Pretorius and Steyn, 2016;Workneh, 2017). Temperature and relative humidity are also crucial factors to consider (Toerien, 1986;Bower, 1988;Vorster et al., 1990), but are more easily controlled and maintained during transportation and storage. ...
... Instrumentation developed to date, such as the instrumented spheres, are designed to register high amplitude vibrations (20 G) (Ruiz-Altisent & Ortiz-Canavate, 1992) with poor resolution (1 G) compared to that of the Smavo and modern MEMSbased accelerometers. The improved sensor performance in turn reduces the variability associated with measurements from other commercial devices (Li & Thomas, 2014;Praeger et al., 2013). The softer material construction associated with the Smavo reduces the peak amplitude associated with harder materials of other instrumentation that result in higher amplitude accelerations that are difficult to measure accurately. ...
Cultivation of avocadoes serves as a key economic driver for many countries, including South Africa. Nearly all fresh produce produced forms part of a complex, interconnected transportation chain. Packhouses, representing a wide range of capacities and degrees of mechanization, serve to classify, treat and package the fresh produce prior to distribution by road, rail and ocean to its destination. Reducing the damage or postharvest stresses is paramount to ensure consistent quality of the ripened fruit. Packhouse operations represent the phase associated with the greatest degree of mechanical handling. Until now, quantification of packhouse activities exerted on the fruit has not been quantified with sufficient accuracy to identify characteristics of an optimized packhouse. This paper demonstrates the successful application of a novel sensor platform that measures the linear acceleration and rotational velocity of a typical avocado for 24 packhouses spread throughout South Africa. Unique statistics were developed pertaining to the distribution of contact forces, peak accelerations and rotational velocities, freefall events, freefall distance and impact energy experienced by avocadoes. A Damage Index Score (DIS) was developed to classify the relative performance of the sampled packhouses, alongside identification of key areas of concern where the greatest intensity and variation of postharvest stresses are observed. Improvement of avocado quality as a result of improving deficient practices and equipment ultimately reduces waste, prevalence of postharvest diseases and improves the income for farming communities.
... When a fruit falls with sufficient force against a surface, impact damage occurs, while dynamic damage of a single fruit occurs through fruit-to-fruit impact between packaging. Fruit dropping from trees to the ground during harvesting, dynamic impact between single fruit, and between the fruit and packaging or containers are all causes of impact damage [6]. ...
... Browning index (BI) was calculated to represent purity of the brown color [45] using Equations (4) and (5). Total color difference (∆E) was calculated using different color levels on fruit peel (L*, a*, and b* values) between initial (before impact bruise) [46] and after impact damage for 48 h at the bruise area using Equation (6). ...
Simulated impact damage testing was investigated by fractal image analysis using response surface methodology (RSM) with a central composite design (CCF) on quality of ‘Glom Sali’ guava for drop heights (0.2, 0.4, and 0.6 m), number of drops (1, 3, and 5) and storage temperature conditions (10, 20, and 30 �C). After 48 h, impacted fruit were determined and analyzed for bruise area (BA), bruise volume (BV), browning index (BI), total color difference (DE), image analysis for bruise area (BAI), and fractal dimension (FD) at the bruising region on peeled guava. Results showed that the correlation coefficient (r = 0.6055) between DE and FD value was higher than DE and either BA
(r = 0.3132) or BV (r = 0.2095). The FD variable was determined as a better indicator than conventional measurement (BA or BV) for pulp browning and impact bruising susceptibility. The FD variable also exhibited highest R2adj value (81.69%) among the other five variables, as the highest precision model with high determination coefficient value (R2adj) (>0.8) for impact bruising prediction. Recommended condition of the FD variable to minimize impact bruising was drop height of 0.53 m for five drops
under storage at 30 �C. FD variable assessed by image analysis was shown to be a highly capable measurement to determine impact bruising susceptibility in guava fruit.
... Post-harvest operations include a complex route from the garden to the market [3,4] which includes various operations such as harvesting, packaging, sorting, storage, and transportation. Although during these operations every effort is made not to damage the fruit, nevertheless often fruit suffers from mechanical damage caused by either dynamic or static load [5,6]. Lemon bruises are of great concern to the lemon industry and retailers because they reduce not only the visual appearance, but also the quality of the fruit and thus can cause significant economic losses. ...
The presence of bruises on fruits often indicates cell damage, which can lead to a decrease in the ability of the peel to keep oxygen away from the fruits, and as a result, oxygen breaks down cell walls and membranes damaging fruit content. When chemicals in the fruit are oxidized by enzymes such as polyphenol oxidase, the chemical reaction produces an undesirable and apparent brown color effect, among others. Early detection of bruising prevents low-quality fruit from entering the consumer market. Hereupon, the present paper aims at early identification of bruised lemon fruits using 3D-convolutional neural networks (3D-CNN) via a local spectral-spatial hyperspectral imaging technique, which takes into account adjacent image pixel information in both the frequency (wavelength) and spatial domains of a 3D-tensor hyperspectral image of input lemon fruits. A total of 70 sound lemons were picked up from orchards. First, all fruits were labeled and the hyperspectral images (wavelength range 400–1100 nm) were captured as belonging to the healthy (unbruised) class (class label 0). Next, bruising was applied to each lemon by freefall. Then, the hyperspectral images of all bruised samples were captured in a time gap of 8 (class label 1) and 16 h (class label 2) after bruising was induced, thus resulting in a 3-class ternary classification problem. Four well-known 3D-CNN model namely ResNet, ShuffleNet, DenseNet, and MobileNet were used to classify bruised lemons in Python. Results revealed that the highest classification accuracy (90.47%) was obtained by the ResNet model, followed by DenseNet (85.71%), ShuffleNet (80.95%) and MobileNet (73.80%); all over the test set. ResNet model had larger parameter sizes, but it was proven to be trained faster than other models with fewer number of free parameters. ShuffleNet and MobileNet were easier to train and they needed less storage, but they could not achieve a classification error as low as the other two counterparts.
... Impact damage occurs when the fruit drops with adequate force onto a surface, while dynamic damage of single fruit occurs in fruit-to-fruit impact and between packaging. Impact damage usually happens in free drops of fruit from trees to the ground during harvesting, from dynamic impact between single fruit and between the fruit and packaging or containers [4]. Various factors affect impact bruise damage testing such as drop height, number of drops, impact surface and packaging [5]. ...
Impact bruise damage and quality of ‘Gim Ju’ guava were investigated for different drop heights and number of drops using fractal image analysis. For the impact test, a stainless-steel metal ball (250 g) was dropped on fruit from three drop heights (0, 0.3,
0.6 m) either once or five times. Fruit quality was evaluated for impact energy, bruise area (BA), bruise volume (BV), bruise susceptibility, bruise score and pulp color (L*, a*, b* and C
values). The fractal dimension (FD) value using fractal image analysis was analyzed at the bruise region. Results showed that five drops (0.3 m) with a high impact energy (3678.75 J) and a single drop (0.6 m) with a low impact energy (1471.50 J) exhibited no significant in BA, BV, bruise score as well as all color values (L*, a*, b* and C). While the FD value of a single drop from 0.6 m had a higher FD value than that of five drops from 0.3 m. It is indicated
that FD exhibited a better performance to classify impact bruising level of guava than BA, BV and color parameters. The FD value gradually decreased with increase of storage time and bruise severity. The correlation coefficient (r) values of FD (r = - 0.794
and - 0.745) between BA and BV were more significant than those L* (r = - 0.660 and - 0.615) and a* (r = 0.579 and 0.473). The coefficient of determination (R2) of the polynomial
equation in bruised fruit (R2 = 0.85 to 0.99) was greater than the control (no bruise) (R2 = 0.80). A higher R2val (0.88 and 0.92) was exhibited at five drops. Interestingly, FD analysis showed greater potential than color measurement to assess bruise impact damage in guava.
... The most prevalent sort of mechanical injury that occurs during harvesting, handling, and transportation is bruising [37,38]. Bruise damage occurs when an excessive amount of external force is applied to the fruit surface during interaction with a solid body or fruit versus other fruit [39,40]. The most unfavourable damage is bruising, which serves as a portal for infections, particularly fungus [41]. ...
Strawberry is a fruit with a short season of harvest. Strawberry is well-known among people all over the world for its distinct flavour, nutritional value, and delicacy. While on the other hand, preserving strawberry and shelf life extension has been a huge difficulty due to their perishable nature. Making effective and sustainable use of already available food processing and preservation technology needs time. Researchers must use advanced techniques like a cool store, modified atmospheric packaging (MAP), cool store, controlled atmospheric storage (CA), various packaging methods, and a variety of chemical and physical treatments to retain commodities for a longer period due to strategic market sales following harvest. Except for the preserving techniques, there is some polysaccharide-based edible coating which has a crucial role in delaying fruit softening, fruit decay, maintaining the increased levels of ascorbic acid and phenols, enhancing the activities of antioxidant enzymes, and reducing membrane damage. During the postharvest stages, there are numerous threats to keep in view regarding the safety and quality of strawberries. In this chapter , we will discuss the benefits and drawbacks of some of the various preservation technologies, as well as how they might be utilised to preserve and a prolonged period of freshly harvested strawberries.
... However, such measures are limited by the requirement for personnel with expert training to do the handling, which is not always feasible, especially in developing countries [4]. Grading and sorting of produce based on the presence and degree of defects can help in repurposing them for appropriate uses, such as animal feed or processing when their consumer acceptability is not ideal for market display, and thus reduce the likelihood for further disease spread if fruit skin is broken [5,6]. This can also be an alternative and/or complementary solution for further reduction of losses and ensuring quality and safety of fresh produce. ...
Spectroscopy data are useful for modelling biological systems such as predicting quality parameters of horticultural products. However, using the wide spectrum of wavelengths is not practical in a production setting. Such data are of high dimensional nature and they tend to result in complex models that are not easily understood. Furthermore, collinearity between different wavelengths dictates that some of the data variables are redundant and may even contribute noise. The use of variable selection methods is one efficient way to obtain an optimal model, andthis was the aim of this work. Taking advantage of a non-contact spectrometer, near infrared spectral data in the range of 800–2500 nm were used to classify bruise damage in three apple cultivars, namely ‘Golden Delicious’, ‘Granny Smith’ and ‘Royal Gala’. Six prominent machine learning classification algorithms were employed, and two variable selection methods were used to determine the most relevant wavelengths for the problem of distinguishing between bruised and non-bruised fruit. The selected wavelengths clustered around 900 nm, 1300 nm, 1500 nm and 1900 nm. The best results were achieved using linear regression and support vector machine based on up to 40 wavelengths: these methods reached precision values in the range of 0.79–0.86, which were all comparable (within error bars) to a classifier based on the entire range of frequencies. The results also provided an open-source based framework that is useful towards the development of multi-spectral applications such as rapid grading of apples based on mechanical damage, and it can also be emulated and applied for other types of defects on fresh produce.
... Khaled et al. [14] demonstrated that several impedance parameters are correlated with fruit firmness. Li et al. [15] studied the relationship between fruit firmness and electrical parameters of kiwifruit during storage and suggested that dissipation factor (D) and parallel equivalent capacitance (Cp) are positively correlated with fruit firmness, while impedance (Z), parallel equivalent resistance (Rp), and parallel equivalent inductance (Lp) have negative correlations with fruit firmness. The above studies demonstrate the feasibility of detecting the fruit firmness of pears based on electrical properties. ...
... Fresh fruit is made up of millions of cells of different shapes and sizes arranged in close proximity (Li & Thomas, 2014). Cells' morphology and spatial arrangement determine the fruit size, shape, and textural properties (Li, Ding, Kitazawa, & Wang, 2022). ...
Fruit cells are living irregular 3D transparent objects which makes them challenging to determine their real 3D size and shape through only two‐dimensional (2D) images using the existing biological microscope. This study deals with a newly self‐developed biological microscope including a microscope imaging system, a light source system, a stage and a support base for the 3D size characterization of fruit single cells. The main design concept is based on two optical path systems set up at the front (x‐axis) and bottom (z‐axis) directions of a transparent chamber containing single cells that allow the front view and bottom view of the single cell to be observed. Performance indicators such as mass, size, observation range, objective magnification, total magnification, focal range, focal accuracy and resolution of the developed biological microscope were estimated. Finally, the 3D geometry size of single tomato cells was measured by the new biological microscope to demonstrate the relative ease at which accurate real 3D geometry information of single fruit cells could be obtained, which echoes its scientific value.
... As one of the economically important vegetable products, cabbage occupies a crucial position in agricultural products. The dents and cracks of cabbage caused by extrusion and collection during transportation have a direct impact both on the commercial value and storage time (Li and Thomas, 2014). The vegetable non-destructive system is a recent trend for quality evaluation, post-harvest classification, and grading (Fathizadeh et al., 2020;Zhang et al., 2021). ...
The dents and cracks of cabbage caused by mechanical damage during transportation have a direct impact on both commercial value and storage time. In this study, a method for surface defect detection of cabbage is proposed based on the curvature feature of the 3D point cloud. First, the red-green-blue (RGB) images and depth images are collected using a RealSense-D455 depth camera for 3D point cloud reconstruction. Then, the region of interest (ROI) is extracted by statistical filtering and Euclidean clustering segmentation algorithm, and the 3D point cloud of cabbage is segmented from background noise. Then, the curvature features of the 3D point cloud are calculated using the estimated normal vector based on the least square plane fitting method. Finally, the curvature threshold is determined according to the curvature characteristic parameters, and the surface defect type and area can be detected. The flat-headed cabbage and round-headed cabbage are selected to test the surface damage of dents and cracks. The test results show that the average detection accuracy of this proposed method is 96.25%, in which, the average detection accuracy of dents is 93.3% and the average detection accuracy of cracks is 96.67%, suggesting high detection accuracy and good adaptability for various cabbages. This study provides important technical support for automatic and non-destructive detection of cabbage surface defects.
... Fruit is an important part of the human diet; it provides essential micronutrients, phenols, organic acids, antioxidants, vitamins, and dietary fiber [1][2][3][4], and fruit phytochemicals play an important role in reducing the risk of chronic diseases [5,6]. Apples are among the world's most popular fruit species, with more than 80 million tons of apples produced annually worldwide. ...
Apples are easily damaged during transportation due to extrusion and collision, resulting in structural damage and deterioration. To better understand apples' mechanical-structural damage behavior, a texture analyzer platform combined with in situ observation was established. The effects of extrusion distance, speed, working temperature, and typical kinds of apple were considered for damage mechanisms. Apple damage was analyzed via the finite element method (FEM). The results indicated that the apple extrusion behavior can be divided into elastic interaction and plastic damage. Compression displacement effects were obviously significant in terms of structural damage, and apple samples were in an elastic stage with displacement of less than 2.3 mm, and no structural damage. The peak force energy-displacement mathematical model was established, showing an "s" shape and upward parabolic shape. The critical compression energy was around 100N·mm during elastic interaction. The damaged area was positively correlated with the compression energy. The FEM simulation results were consistent with the damage distribution of apples. The effects of speed on the three apple types were different. Red Fuji apples with a bruised area were not sensitive to pressure speed. The effect on the crack forming of Ralls apples was significant. Golden Delicious apples with a bruised area and crack formation showed an intermediate effect. The peak force-temperature fitting curve showed a downward parabolic shape and an R2 determination factor of 0.99982. Apple squeeze damage mechanisms provide theoretical guidance for apple damage control.
... Mechanical damage during harvesting tends to result in a substantial reduction in fruit quality (Li & Thomas, 2014). Mechanical abrasions and bruising on fruit can accelerate water loss, increasing the chance of rotting fungi and bacteria penetrating the fruit and causing rapid decay (Trimble, 2021). ...
Intelligent robots for fruit harvesting have been actively developed over the past decades to bridge the increasing gap between feeding a rapidly growing population and limited labour resources. Despite significant advancements in this field, widespread use of harvesting robots in orchards is yet to be seen. To identify the challenges and formulate future research and development directions, this work reviews the state-of-the-art of intelligent fruit harvesting robots by comparing their system architectures, visual perception approaches, fruit detachment methods and system performances. The potential reasons behind the inadequate performance of existing harvesting robots are analysed and a novel map of challenges and potential research directions is created, considering both environmental factors and user requirements.
... The amount of waste after harvesting of fruits due to mechanical damage was estimated to be about 30-40% [7]. If the transport does not appropriate, it will cause heavy movement of the fruit during transportation, and the collision with the surfaces of the vehicle, lead to deformation of the tissues [8]. ...
Post-harvest processes, such as transportation and packaging, should be carried out in such a way that less damage is made to the product. Inappropriate transport of fruits causes mechanical damage. Transport vibrations have a great effect on the extent of damage to agricultural products. In this research, the effects of road vibration on the mechanical properties of olive fruit, including fracture force, fracture energy and elasticity modulus were measured through pressure testing by the instrument before and after Vibration and results were checked. The effect of different parameters of vibrations caused by road transport (frequency, acceleration and time) on the mechanical properties of olive was investigated. Experiments were carried out at two levels of 7.5 Hz and 13 Hz, two acceleration levels of 0.3g and 0.7g and two levels of 30 and 60 minutes. The results of the data analysis showed that the effects of vibration frequency, vibration acceleration, vibration duration were significant on the amount of damage during vibration at the 1% level. The factors caused reduction in mechanical properties.
... Future research will thus need to develop standard methods to accurately and rapidly evaluate the plethora of different packaging combinations towards better produce protection. Potential solutions include the development of multi-scale finite element modelling approaches to simulate the various interactions and effects between the packaging and packing configuration on fresh produce damage (Li et al., 2013;Li and Thomas, 2014). Alternatively, the use of discrete element methods to capture vibration and impact forces on packaged produce may be a potentially valuable evaluation approach in the future (Caulkin et al., 2015;Kosteski et al., 2015;Scheffler et al., 2018). ...
Horticultural packaging is a critical component of the cold chain and influences both the preservation of fresh produce quality as well as the efficiency of cold chain operations. Development and optimisation of packaging designs is a multidisciplinary task. Nevertheless, knowledge and expertise are often not transferred between domain specialists. This review, therefore, provides a summary of the existing science and practices used to design corrugated paperboard packaging systems. We investigate the main interactions and challenges affecting package design decisions. Recent studies towards an optimised carton design were reviewed for each of the various cold chain unit operations. We identified existing knowledge gaps in the areas of food cooling performance and mechanical strength of the boxes, particularly for stacked packages and cartons packed with internal packaging such as liners. Future prospects indicate a more widespread application of multi-scale experimental and simulation approaches towards improved packaging design, where multiple packaging performance indicators are evaluated simultaneously .
... Moreover, quality and safety evaluations of food and agricultural products are directly related to human health and social development. The accurate identification of damaged fruits can eliminate rotten fruits as soon as possible, which is beneficial to postharvest storage (Li & Thomas, 2014). The development of a nondestructive technology that can quickly and effectively determine whether strawberries have bruises at an early time and automatically classify them is essential for commercial inspections. ...
The detection of bruises plays a vital role in the quality evaluation of strawberries. This study aimed to detect strawberry bruises based on thermal images and classify bruises using a convolutional neural network (CNN). A simple active thermal imaging system was used to capture 2903 thermal images collected from 400 strawberries over 5 days. Moreover, the temperature difference between the bruised area and the unbruised area of the strawberry over time was analyzed. Some of the most advanced pretrained CNN models and the optimized CNN model were evaluated for the classification of unbruised and bruised strawberries based on collected thermal images. The results show that the accuracy of the optimized CNN network is 0.98, which is much higher than the accuracy of the pretrained models. Thus, this study provides a high degree of accuracy in the classification of unbruised and bruised strawberries using the optimized CNN model based on its thermal images, indicating which can be an effective method of detecting and classifying strawberries.
... The severity and occurrence of scuffing was observed to increase with maturity in pears (Thompson 2007;Calvo et al. 2011;Gomila et al. 2011) or more aptly with softening as the same effect can be observed during ripening. Thus, scuffing may rely on a fruit losing its resistance to deformation during softening much like that observed in impact and compression bruising for pears (Mitcham et al. 2001;Thompson 2007;Stropek and Gołacki 2019) and apples (Garcı́a et al. 1995) and discussed in a review by Li and Thomas (2014). ...
Kiwifruit (Actinidia chinensis var. chinensis ‘Zesy002’) have a relatively long harvest season, where fruit will change in maturity and hence attributes. Harvest may be followed by a long postharvest storage period. Scuffing is the discolouration of kiwifruit skin in response to an injury. This injury is observed throughout the supply chain to some extent and thus, it is of interest to identify possible reasons that predispose kiwifruit to skin discolouration. In this work, maturity, as influenced by harvest date and estimated by firmness and total soluble solids, was investigated as a potential descriptor of scuffing susceptibility. ‘Zesy002’ kiwifruit were sampled from 11 orchards in New Zealand on three occasions (ISO weeks 12, 18 and 20) during the 2020 harvest season. Upon arrival to the lab, 24 fruit from each grower were non-destructively assessed prior to a deliberately controlled scuffing treatment and subsequently stored for 2 weeks at 0°C, to allow symptom development. Of the at-harvest maturity indicators, firmness was found to be the strongest indicator of scuffing susceptibility and severity of the damage. Further work is required to understand the physical or physiological reasons that cause softer fruit to be more susceptible to scuffing.
... Another factor that affects the quality and shelf life of the product is mechanical damages arising from impacts, wind forces, and environmental conditions. Mechanical damages lead to metabolic changes, tissue failure, and crushing, scratches, pigment deterioration, etc., on the surface or inner tissues of the product [43,44]. Some of the mechanical damage to citrus fruit is bruising, cuts, and compression. ...
Today in the agricultural industry, many defects affect production efficiency; this paper aims to show how the combination of machine vision (MV) and image processing (IP) helps to detect the defective areas of products. Defects generally appear due to insect damage, scarring, product decay, and so on. In this review, the importance of quality inspection in the agricultural industry and its effect on worldwide markets are highlighted and the ways which help to categorize the products by their defections. In the first step, as long as agricultural products are harvested, in a suitable condition with good illumination, they are photographed by special cameras and evaluated by the IP science. In the next step, they can be classified based on the detected defection. Many classification algorithms allow us to categorize products based on the quality and type of their defects. Using a combination of MV and IP, followed by the use of special classification algorithms, helps to have more efficiency in the detection of defects in harvested products.
... Harvested fruits may become contaminated with farm spores if they are kept on the field for longer than four hours after being spread on the ground during harvesting. Picking fruits with hand compression can cause harm when the respiratory forces around the fruit reach one end for tissue breakage [26]. It focuses on the importance of using proper picking techniques to avoid fruit injury. ...
Aims: Post-harvest losses are acknowledged as one of the major reasons for fresh grain production, especially fruit production in most developing countries. Thus, the present study is highlighted the perishable nature of the food and inefficient post-harvest management are one of the key reasons for fruit (pineapple) losses in the Moulvibazar district. Study Design: This article is about determinants of post-harvest losses study and is placed on empirical analysis. It was carried out to find out what factors influence pineapple post-harvest losses at the farm level. Place and Duration of Study: Sreemangal, Barlekha, Kulaura, Juri, and Rajnagar Upazilas were Original Research Article Begum et al.; SAJSSE, 13(3): 40-51, 2022; Article no.SAJSSE.84642 41 purposively chosen for this study because they represent the five most important pineapple producing locations in the Moulvibazar district. The study period was the harvesting season of pineapple from April to June 2019. Methodology: Structured questionnaires were used to collect relevant information during face-to-face interviews with 320 pineapple farmers who were chosen using simple random sampling. Then the data were examined using descriptive and inferential statistics such as chi-square and factor analysis. Results: The descriptive analysis shows that, based on the ranking of percentage, all pineapple farmers (100%) were engaged in the marketing of pineapple in order to reduce losses by exploring both direct and indirect means to sell their produce. This means that in order to avoid losses, finding a market for pineapples is important. There was a substantial link between the level of education (P=0.049), farm size (P=0.000), farm experience (P=0.021), yield (P=0.000), and post-harvest losses, as per chi-square analysis. Furthermore, according to the findings of the factor analysis, harvesting, grading, sorting, storage, packaging, transportation, and marketing are all aspects that affect post-harvest losses of pineapple at the farm level in the study area. Implementing proper storage and packaging facilities can reduce pineapple farmers' losses and make it easier for them to market their products year-round. Moreover, sorting and grading pineapple increases its price, enabling more effective marketing.
... The obvious indication of bruising is the resultant physiological changes in the fruit, such as loss of quality, loss of water, and changes in firmness and color that eventually reduce the quality and shelf life of the fruit, and ultimately reduce the commercial value of the fruit (Scherrer-Montero, dos Santos, Andreazza, Getz, & Bender, 2011). However, in most cases, fruit bruising is hard to detect with the naked eye, and minor bruises can also aggravate rotting and molding during storage and long-distance transportation (Al-Dairi, Pathare, & Al-Yahyai, 2021), infect healthy fruits, and cause potential food safety problems (Li & Thomas, 2014;Lu & Lu, 2017a;Lu & Lu, 2017b). Early bruise to the fruit is slight, and will not have much impact on the edible value of the fruit. ...
Jujubes (Ziziphus Mauritiana Lamk) are subjected to bruises during harvesting and post‐harvest processing, which will greatly reduce their commercial values. In this study, bruises on jujube are detected and classified based on thermal imaging and convolutional neural networks. A simple thermal imaging system is constructed that can capture thermal images speedily and clearly. Temperature difference analysis is performed on the collected thermal images and accordingly, the temperature difference of boundary in the bruised area varies between 1.72 and 3.25°C during the storage period. The temperature difference in the bruise boundary area minus the temperature difference in the center area varies between 0.4 and 1.2°C, and the degree of bruise of the jujube is evaluated through temperature difference analysis. The convolutional neural network DenseNet is adjusted to ensure suitability for classification of the thermal image data set collected in this study (the training dataset comprises 5,039 original thermal images, and the test dataset comprises 2,586 original thermal images), and the best prediction accuracy achieved is 99.5%.
Practical Application
This study can be used as a reference for the future development of harvest, sorting, storage, and transportation for bruise detection in jujube. Our study makes a significant contribution to the literature because the findings of this study could facilitate the development of an online thermal imaging system for bruise detection and classification in jujube in the future.
... Nevertheless, strawberry is soft and, therefore, very vulnerable to mechanical damage during the postharvest supply chain. Impact, compression, and vibration are the main mechanical forces that can cause fruit damage [1,2]. When fruit is mechanically damaged, its physiological metabolism becomes abnormal, such as quick softening [3], water losses [4], and oxidation browning [5]. ...
Strawberries are susceptible to mechanical damage. The detection of damaged strawberries by their volatile organic compounds (VOCs) can avoid the deficiencies of manual observation and spectral imaging technologies that cannot detect packaged fruits. In the present study, the detection of strawberries with impact damage is investigated using electronic nose (e-nose) technology. The results show that the e-nose technology can be used to detect strawberries that have suffered impact damage. The best model for detecting the extent of impact damage had a residual predictive deviation (RPD) value of 2.730, and the correct rate of the best model for identifying the damaged strawberries was 97.5%. However, the accuracy of the prediction of the occurrence time of impact was poor, and the RPD value of the best model was only 1.969. In addition, the gas chromatography–mass spectrophotometry analysis further shows that the VOCs of the strawberries changed after suffering impact damage, which was the reason why the e-nose technology could detect the damaged fruit. The above results show that the mechanical force of impact caused changes in the VOCs of strawberries and that it is possible to detect strawberries that have suffered impact damage using e-nose technology.
... The application of impact directly to the fruit surface can cause external bruising on the surface and/or internal bruising of the flesh (Opara and Pathare 2014). The physical evidence of external bruising onto fresh produce was reported as any defect such as skin rupture and/or manifestation of discoloration of injured tissue, which marks the damaged spot (Hussein et al. 2018;Li and Thomas 2014). In the present study, external bruising in the 'Carabao' mango was manifested as retention of green color on the skin at the impact site ( Figure 3). ...
Poor handling results in bruising which translates into losses for the Philippine 'Carabao' mango fruit industry. This study determined bruise injury in 'Carabao' fruit as affected by harvest method, dropping from heights of up to 5 m, and interaction of ripeness stage [viz. mature green (MG), more yellow than green (MYG), and fully yellow (FY)] and dropping from 0.5 m up to 1.5 m. Mangoes harvested carefully or by the conventional method consistently had better visual quality at harvest and a lower degree of anthracnose and stem-end rot at the table ripe (TR) stage than those that were dropped. As the drop height increased, cracked fruit, weight loss, and bruised flesh also increased in terms of incidence and severity. There was a positive correlation between the kinetic energy at impact and bruised flesh (y = 2.63x + 20.52, R 2 = 0.26, P = 0.02). Retention of green color on the bruised skin surface was evident on mangoes dropped at the MG stage. Subtending bruised flesh was characterized by a white mass of unhydrolyzed starch. Fruit dropped at the MYG stage had soft and opaque bruised flesh. Those dropped at the FY stage had transparent jelly-like bruised flesh beneath the impact site. This study on 'Carabao' mango fruit illustrates that the extent of damage appeared throughout the ripe stage, especially if the fruit does not sustain a crack when dropped. The serial symptomology could be gainfully used in quality assessments in the supply chain to help identify the maturity stages at which these damages occur. This also highlights the importance of avoiding physical damage at harvest and when the fruit progress through ripening.
... Laboratory tests have shown that fruit located on the top layer of a pile exhibits more damage than those located at the bottom layer. This increased damage is caused by a higher level of acceleration in the upper layer [5][6][7]. Mechanical damage is difficult to eliminate because biological material consists of a delicate cell structure. Therefore, it is important to reduce impact intensity by absorbing part of the energy to reduce negative influences on the tested fruit. ...
From the producers’ point of view, there is no universal and quick method to predict bruise area when dropping an apple from a certain height onto a certain type of substrate. In this study the authors presented a very simple method to estimate bruise volume based on drop height and substrate material. Three varieties of apples were selected for the study: Idared, Golden Delicious, and Jonagold. Their weight, turgor, moisture, and sugar content were measured to determine morphological differences. In the next step, fruit bruise volumes were determined after a free fall test from a height of 10 to 150 mm in 10 mm increments. Based on the results of the research, linear regression models were performed to predict bruise volume on the basis of the drop height and type of substrate on which the fruit was dropped. Wood and concrete represented the stiffest substrates and it was expected that wood would respond more subtly during the free fall test. Meanwhile, wood appeared to react almost identically to concrete. Corrugated cardboard minimized bruising at the lowest discharge heights, but as the drop height increased, the cardboard degraded and the apple bruising level reached the results as for wood and concrete. Contrary to cardboard, the foam protected apples from bruising up to a drop height of 50 mm and absorbed kinetic energy up to the highest drop heights. Idared proved to be the most resistant to damage, while Golden Delicious was medium and Jonagold was least resistant to damage. Numerical models are a practical tool to quickly estimate bruise volume with an accuracy of about 75% for collective models (including all cultivars dropped on each of the given substrate) and 93% for separate models (including single cultivar dropped on each of the given substrate).
... Fresh market produce, such as raw fruits and vegetables, are popular nutritional foods, because they are rich in important vitamins, minerals, antioxidants, and nutrients that provide positive benefits to human health [1,2]. Cucumber (Cucumis sativus L.), a member of the Cucurbitaceae plant family, is an economically important crop cultivated throughout the world. ...
The widespread use of nitrogen chemical fertilizers in modern agricultural practices has raised concerns over hazardous accumulations of nitrogen-based compounds in crop foods and in agricultural soils due to nitrogen overfertilization. Many vegetables accumulate and retain large amounts of nitrites and nitrates due to repeated nitrogen applications or excess use of nitrogen fertilizers. Consequently, the consumption of high-nitrate crop foods may cause health risks to humans. The effects of varying urea-nitrogen fertilizer application rates on VOC emissions from cucumber fruits were investigated using an experimental MOS electronic-nose (e-nose) device based on differences in sensor-array responses to volatile emissions from fruits, recorded following different urea fertilizer treatments. Urea fertilizer was applied to cucumber plants at treatment rates equivalent to 0, 100, 200, 300, and 400 kg/ha. Cucumber fruits were then harvested twice, 4 and 5 months after seed planting, and evaluated for VOC emissions using an e-nose technology to assess differences in smellprint signatures associated with different urea application rates. The electrical signals from the e-nose sensor array data outputs were subjected to four aroma classification methods , including: linear and quadratic discriminant analysis (LDA-QDA), support vector machines (SVM), and artificial neural networks (ANN). The results suggest that combining the MOS e-nose technology with QDA is a promising method for rapidly monitoring urea fertilizer application rates applied to cucumber plants based on changes in VOC emissions from cucumber fruits. This new monitoring tool could be useful in adjusting future urea fertilizer application rates to help prevent nitrogen overfertilization.
... Agricultural products, such as fruits and vegetables, are essential components of human diet and provide a variety of nutrients for the human body (Li & Thomas, 2014). As the world's population grows steadily, human demand for agricultural products also increases. ...
It is very necessary to understand the mechanical properties of Rosa roxburghii fruit for harvesting, packaging, processing, transportation, storage, and related equipment design and improvement. This research was to determine the mechanical properties of R. roxburghii fruits through compressive experiments and finite element simulations and to verify the accuracy of the finite element model. In order to achieve finite element analysis, an accurate three-dimensional (3D) geometric model was reconstructed by applying 3D laser technology and point cloud reconstruction algorithm. The elastic modulus and Poisson's ratio of R. roxburghii fruits were determined to be 4.0 MPa and 0.35 through experiments. The finite element simulation results provided valuable numerical data and visualized stress distribution. The simulation results showed that R. roxburghii fruits were damaged under the loads of 156.2 N (vertical) or 148.3 N (horizontal), with a maximum deformation of 5.0 mm (vertical) or 6.93 mm (horizontal), respectively. In the vertical and horizontal compression positions, the maximum relative errors between the experimental results and the finite element model are 24.71 and 13.99%, respectively. The results of the compressive strain energy of the fruit showed that the maximum relative error between the experimentally measured strain energy and the strain energy calculated by FEM simulation was 9.20 and 2.09% in the vertical and horizontal directions, respectively.
Practical Applications
As there is no relevant literature on the mechanical analysis of Rosa roxburghii fruit, the finite element method has been successfully applied to analyze the mechanical properties of R. roxburghii fruit under compressive load. At the same time, the simulation results have also been verified by experimental data, and the finite element technology has certain application prospects in food processing engineering. This study proposes a method based on 3D scanning technology and point cloud reconstruction algorithm to reconstruct an accurate geometric model of R. roxburghii fruit for finite element simulation, and conducts an in-depth analysis on the stress, strain, and strain energy of the fruit. The purpose of this article is to propose a reliable method to predict the mechanical properties of the fruits under compressive load. The finite element simulation results can not only provide the basic data needed for fruit packaging and protection but also can be used for the design of automated fruit picking manipulators and the improvement of fruit processing equipment.
... Unfortunately, fresh fruit is susceptible to mechanical damage, and quality can be significantly reduced due to poor distribution and pre-and post-processing processes [10][11][12]. Once damaged, fruits and vegetables deteriorate quickly due to physiological effects depending on the distribution period, resulting in considerable deterioration in the quality of fruits and vegetables during distribution [13,14]. Most of the circular shaped cherry tomato varieties are cultivated in Japan and exported at a high cost. ...
A prototype for the remover of cherry tomato calyxes was designed and manufactured. The tap remover was designed and manufactured considering the conveyor transport speed, brush length and clearance, and diameter. These were adjusted in three levels to determine the optimal design factor. Performance tests were conducted using Icon 513, a circular-shaped cherry tomato variety, and Minimaru, a jujube-shaped cherry tomato variety. Conveyor transport speeds were set at 210, 280, and 350 mm/s; brush lengths at 70, 80, and 90 mm; brush clearances at 20, 22, and 24 mm; and brush diameters at 0.8, 1.0, and 1.2 mm. The two varieties showed a similar damage rate during calyx removal. However, Minimaru showed a higher calyx removal rate than Icon 513, indicating that it is most suitable for the calyx removal mechanization process.
... The harvest procedure is a crucial stage to reduce bruises. Apple picking can cause compression damage to the fruit, when pickers grasp the fruit too tight (Li and Thomas 2014). Pickers need to be trained to pick the apples gently by use of a whole hand grip and an upward bending movement to detach the fruit with the stalk (Knee and Miller 2002) and pick the apples with their stalk. ...
India is the fifth-largest apple producer in the world with more than 2 mil metric tons per year, twice the apples grown in Germany. Mechanical damage such as bruises of apples (Malus domestica Borkh.), which can result in considerable wastage and decline in quality, is a major problem of the apple industry. On-site investigations of apple orchard management strategies to reduce bruises in Northern India were conducted in collaboration with the University of Bonn. The apple industry including the farmers isare in a continuous process of reducing losses caused by mechanical damage. Apple bruises can develop along the whole value chain. Orchard management offers countermeasures to reduce bruise susceptibility of the apples. At harvest, bruises can be caused by impact and compression forces due to unsuitable practices. This review explains the formation and development of bruises, followed by the causes of mechanical damage and orchard management measures to reduce or avoid bruises, with particular regard to India. The orchard management measures include crop load management, fruit water status and nutrient composition, maturity stage, harvest time later in the day, gentle harvest methods, packing into soft, padded bins and careful transport of the apple bins out of the orchard.
... Generally, fruit injury is the result of one or more impacts: (a) during fruit detachment; (b) limb contact when falling; (c) striking the catch frame surface; and/ or (d) striking other fruits during detachment, falling, or catching. The level of bruising depends on the type and texture of the fruit, maturity level, fruit-to-fruit contact, the distance between the fruit and the catching surface, and the type of catching surface (Ma et al. 2016;He 2018;Li and Thomas 2014). Control over these factors is limited. ...
Manual harvesting of fruits is an expensive, time-consuming, and laborintensive operation. Due to labor shortages in the late 1950s, mechanical harvesters were developed to reduce the need for labor and to reduce cost. The most common mechanical harvesters are limb, trunk, and canopy shakers. Catch frames are used during mechanical harvesting to collect fruits and reduce fruit damage. Efficient fruit harvesting without tree damage requires selecting the appropriate harvesting technology based on:(1) tree characteristics–type, size, natural frequency, damping properties, and the architecture of the tree;(2) fruit properties–shape, size, stem length, and maturity level; and (3) vibration techniques–shaker type, mass, amplitude, excitation frequency, and clamp position. Although mechanical harvesting increases harvest efficiency, it has disadvantages, which can include (a) tree injury,(b) fruit damage,(c) debris and
... Comparing the firmness value when unpacking, vacuum packaging would reduce the firmness of the bayberry fruit, especially the BQ bayberry fruit (p < .05). The review by Li and Thomas described that compression occurs primarily during or after packing due to forcing too many products into too small a container (Li and Thomas, 2014). Result suggests that semi-vacuum packaging may compact the bayberry fruit in the fruit basket, which will cause the bayberry fruit to suffer a certain degree of crush injury. ...
Recent years have witnessed rapid advances in the transportation of Chinese bayberry fruit in China by express delivery (ED). The mainstream express packaging is a fruit basket filled with Chinese bayberry fruit. In order to analyze the vibration, impact and quality changes of bayberry fruit in the actual ED process, BiQi (BQ) and Dongkui (DK) bayberry fruit were selected as experimental objects. Real‐time acceleration and temperature of Chinese bayberry fruit in the package were recorded during ED transportation. Headspace CO2 gas concentration and squeezed juice percentage were measured when unpacking. The firmness and electronic nose (E‐nose) linear discriminant analysis (LDA) statistical results were measured during the 2‐day shelf life. The results show that semivacuum packaging can reduce the vibration intensity of Chinese bayberry fruit in the package. Whether it was BQ or DK bayberry fruit, the fruit quality of Chinese bayberry fruit sent by ED was considerably worse than that of road vehicle (RV) transportation when unpacking. The LDA statistics of E‐nose data showed that ED‐treated bayberry fruit barely constituted the fresh part. However, differences were noticed between the varieties. Compared with DK bayberry fruit, BQ bayberry fruit had more of its juice squeezed; further, its firmness had decreased more. In conclusion, multiple impacts and high‐intensity vibrations are the main reason for Chinese bayberry fruit damage during ED transportation. Compared to BQ bayberry fruit, DK bayberry fruit is more resistant to mechanical damage and is more suitable for ED.
Practical Applications
Cultivar Dongkui bayberry is more resistant to mechanical damage than BiQi bayberry after many aspects of comparison, and is suitable for express delivery (ED) transportation. To reduce the mechanical damage of bayberry fruit, it is suggested to improve the impact‐resistant design of existing packaging styles, with simply adding a layer of absorbent pad to the bottom of the fruit basket. The form of foam box semivacuum packaging is not only suitable to bayberry, but also to others such as strawberries during ED transportation.
The perishability nature of harvested fruits and vegetables, along with the effect of environmental factors, storage
conditions, and transportation, reduce the products' quality and shelf-life. Considerable efforts have been allocated
to alternate conventional coatings based on new edible biopolymers for packaging. Chitosan is an attractive
alternative to synthetic plastic polymers due to its biodegradability, antimicrobial activity, and film-forming
properties. However, its conservative properties can be improved by adding active compounds, limiting microbial
agents' growth and biochemical and physical damages, and enhancing the stored products' quality, shelf-life,
and consumer acceptability. Most of the research on chitosan-based coatings focuses on antimicrobial or antioxidant
properties. Along with the advancement of polymer science and nanotechnology, novel chitosan blends
with multiple functionalities are required and should be fabricated using numerous strategies, especially for application
during storage. This review discusses recent developments in using chitosan as a matrix to fabricate
bioactive edible coatings and their positive impacts on increasing the quality and shelf-life of fruits and vegetables.
The aim of this study was to investigate changes in the volatile organic compound (VOC) profile of apples cv. ‘Golden Delicious’ associated with mechanical damage. The performance of direct and indirect extraction methods and four solid-phase microextraction (SPME) fibres coated with different stationary phases (CAR/PDMS, PDMS, DVB/CAR/PDMS, and CW/TPR) was tested for identifying volatile markers of damaged and sound fruit. Direct extraction and CAR/PDMS fibre were proposed for the extraction of VOCs associated with mechanical damage in apples. Almost half of the 83 compounds extracted were identified as esters (41 different VOCs), followed by hydrocarbons (11), alcohols (10), and terpenoids (7), among others. The more evident changes were an increase of lower molecular weight esters such as methyl, ethyl, and propyl acetate; and a decrease of other higher molecular weight esters such as phenyl ethyl acetate, isobutyl butyrate, and butyl butanoate. The ester ratios suggest that the relation between ethyl acetate and phenyl ethyl acetate is the best option for detecting mechanical damage in cv. ‘Golden Delicious’ apples.
The coefficient of restitution (CoR) is one of the essential parameters required using numerical simulation to investigate materials' kinematics and collision mechanics. This study presented an approach with a sliding method for determining the CoR of apple-to-apple collisions. A platform was developed for performing fruit-to-fruit collisions (FFC) in the air, where pairs of fruit were slid together with sliders created by three-dimensional (3D) printing technology. The CoR involving rotational energy was determined using high-speed photography for different treatments of four collision velocities (0.8, 1.2, 1.6, and 2.0 m s⁻¹), three collision angles (25, 35, and 45°), and across three zones of the fruit (stem shoulder-to-cheek, cheek-to-cheek, and calyx shoulder-to-cheek). The statistical significance between mean values of studied quantities was determined by analysis of variance at a 5% significance level. Results indicated significant effects of collision velocity, collision angle, and their interactions on the CoR. The CoR decreased with increasing collision velocity irrespective of collision angles, but the decrease was smaller at the larger arc. The CoR significantly increased with increased collision angle only under higher speeds, and the increment was also more significant at higher velocities. The total bruise volume varied nonlinearly with increased CoR; thus, CoR could serve as a helpful indicator of the threshold level for fruit bruise damage. The CoR should be over 0.84 without bruise damage on fresh market apples. This methodology and results will help create a more accurate fruit model and thus design optimal apple production systems.
This paper presented an approach using a pendulum method to measure bruise damage of apples to overcome the limitation of the drop test on impact control on a specific fruit zone. Conditions included three impact energies (0.011, 0.042, and 0.094 J) and four repeated series (1, 3, 5, and 10) across three surface zones (top/stem shoulder, middle/cheek, and bottom/calyx shoulder) on large and small fruit. A full factorial experimental design was performed to investigate the effects of these factors on bruise damage. Twelve smaller areas separated from each zone of a pair of large/small apples and twelve treatments between the three impact energies and four repeated impact series corresponded to each other to reduce errors caused by the variance of specimens. Impact parameters (impact force and contact time), bruised area (BA), volume (BV), and susceptibility (BS, the ratio of BV to impact energy) were counted/calculated, respectively. It was demonstrated that the apple surface zone and repeated impact series could significantly affect bruise sizes and susceptibility to bruising. Results indicated that the impact force clearly increased with increased impact series before five impacts, but the increment decreased successively for every single impact, and the same was true for BA and BV, while the contrary was true for BS. More repeated impacts with lower intensity were more likely to reduce BA and BV compared to fewer impacts with higher intensity. The contact time decreased from the top to the bottom zone at both 0.011 and 0.042 J impacts. The fruit zone near the stem was more susceptible to causing smaller bruise sizes at a 0.042 J impact.
Mechanical damage during transportation impairs fruit quality. Protecting fragile fruits through packaging is essential. Herein, this paper presents a case study of fresh strawberries embeded in porous hydrogels (PHs) to maintain quality and avoid damage during shelf-life period. The hydrogels were biologically fabricated using alginate networks and soy protein isolates to yield a porous structure. With three times of foaming rate, the PH could dissipate 70%–78% deformation energy in the first loading cycles. It also maintained an energy dissipation rate of 51.52% after 200 loading cycles. The strawberries stored in these PHs exhibited a remarkably better quality than those in other package materials after transportation simulation and free-fall tests, their damage indices were inhibited under 14% (above 36% in control). Additionally, during a two-day shelf-life period, rotten rate of strawberries after transportation simulation and that after free-fall tests were detected as 2.49 ± 1.86% (48.33 ± 5.67% in control) and 13.34 ± 3.76% (94.96 ± 3.76% in control), respectively. Moreover, PHs possessed a high specific heat capacity of 3956 ± 49 J kg⁻¹ K⁻¹ and a low friction coefficient of 0.081 ± 0.003, maintaining a low temperature around the fruit and avoiding fruit abrasion. The PHs were also biodegradable. Therefore, the PHs was considered as promising packaging for maintaining fresh and fragile produce.
Mechanical vibrations including ultrasound play a major role during the processing and distribution of foods as they can have both negative and positive effects. The physical principles of vibrations are presented in a concise manner first, and profound information is provided by reviewing the relevance of vibrations in the food industry. On the one hand, this review elucidates common vibration sources and reports on their negative impact on structures, processing plants, and foods. In particular, vibrations occurring during the transportation of food are discussed, and their potential to cause damage to various food products is pointed out by the cited literature. On the other hand, this review likewise illustrates that vibrations are beneficially used for various unit operations during processing as well as analytical purposes. Ultrasound is considered separately by describing its principles, demonstrating versatile applications, and reporting on current advances in food technology.
Measuring the ripeness of fruits is one of the critical factors in achieving real-time quality control and sorting of fruit by growers and postharvest managers. However, recent tactile sensing approaches for fruit ripeness detection have suffered setbacks due to: (1) the nonlinear relationship between the sensor output and the true stiffness of fruits; and (2) the angle of contact, referred to as the inclination angle, between the sensor and the outer surface of the fruit. In this paper, we propose a non-destructive tactile sensing approach for estimating the stiffness of fruits, using kiwifruit as a case study. Our sensor configuration is based on a three-probe piezoresistive cantilever beam, allowing us to obtain relatively stable sensor outputs that are independent of the inclination angle of the fruit surface. Our stiffness estimation approach is based on the combination of instantaneous sensor outputs with 63 regression-based machine learning models comprising of neural networks, Gaussian process, support vector machines, and decision trees. For experiments, we used several kiwifruit samples at diverse ripeness levels. The extracted sensor data was used to train the learning models over a 10-fold cross-validation technique, allowing us to find the nonlinear relationships between the instantaneous sensor outputs and the ground truth stiffness of the fruit. Our pairwise statistical comparison by the Wilcoxon test at 5% significance revealed the competitive performance frontiers of our approach for stiffness prediction; the Gaussian process kernel functions and the binary trees outperformed other models at a mean squared error (MSE) of 1.0 and 2×10^−23 , respectively. Most neural network models achieved competitive learning performance at MSE less than 10^−5 and the utmost performance being a pyramidal class of feed-forward neural architectures. The results portray the potential of achieving accurate ripeness estimation of fruit using intelligent tactile sensors with fast machine learning schemes across the supply chain.
Purpose: Adapting the distribution of fresh fruit to meet consumers' specifications and requirements for quality, safety and sustainability while controlling costs is a complex challenge. Fruit Distribution Management (FDM) is characterized by long-distance transportation, continuous decline in fruit quality in various form combined with significant supply, demand, and price uncertainties, and relatively thin margins. For these reasons, Fruit Distribution Management needs modern decision-making tools to be effective. The main objective of this research is to propose a method for optimizing the logistics needed to export fresh fruit which takes into account the specific challenges of this kind of product.Design/methodology/approach: The methodology is divided into 3 phases.First, the input factors that constitute the logistics costs and determine the loss of quality due to mechanical injuries (MI) and natural decay (ND), as well as the CO2 emissions of each activity are developed. This phase is based on an extended analysis of the literature and the use of real data. Second, we have developed a multi-objective optimization model that integrates both the distribution and inventory planning of fresh fruit (DIP model). This model takes into account the logistics cost, the total greenhouse gas (GHG) emissions, as well as the quality loss due to MI and ND based on two models of kinetic shelf life: zero order (DIP). - ZO) and exponential decay (DIP-ED). The DIP model objective is to optimize the planning for the distribution and storage for fresh fruit. It is based on a bi objective function: maximizing the total net profit (NP) and the percentage of the remaining fruit quality (% QR). Finally, to address this issue, we have applied a Non-Dominated Sorting Genetic Algorithm II (NSGA-II). A numerical study allows us to analyze the solution spaces of the two kinetic shelf life models (DIP-ZO and DIP-ED) according to the variation of supply, demand, and the market price. This study also includes CO2 emissions analysis. The results based on the NSGA-II are then compared with the results of another genetic algorithm based on an adjusted weight-sum approach (AWS-GA) to evaluate the performance of the algorithm.Findings: the results we obtained indicate the efficiency of the NSGA-II algorithm to solve the problem of fresh fruit distribution. Both optimal Pareto front curves of DIP-ZO and DIP-ED show a strong positive relationship between %RQ and NP. They also indicate a negative correlation between % RQ and CO2 emission: reduction of % RQ in both cases is correlated with an increase in CO2. The decision variables can be used to decide on the best schedule for transporting and storing fruit in order to optimize the net profit and remaining quality.Practical implications: The proposed model (DIP-model) allows a significant improvement in the benefits related to the export of fresh fruit while minimizing the loss of quality and the environmental impact. It is a decision support tool that allows exporters to better plan the transport and storage of exported fresh fruits.Originality/value: The distribution and inventory planning model developed in this thesis provides solutions that integrate the kinetics of degradation of fresh fruit. While the other operational research models found in the literature only focus on Natural Decay based on a zero order reaction, our model introduces mechanical injuries, natural decay (zero order and Exponential) and consumer evaluation in the optimization process. This is an innovative approach because former models do not reflect reality, in particular for the international trade in fresh fruit which requires long distance transport.
In order to realize the compliant grasping of apple harvesting robot and reduce the mechanical damage in the process of grasping, a variable damping impedance control strategy for gripper grasping force tracking is proposed based on the establishment of contact force model in this paper. Firstly, the Burgers model is used to characterize the biological characteristics of apple. Then, according to Hertz contact theory, the contact force model of apple during grasping was established to represent the dynamic relationship between grasping force and deformation. Finally, based on the position impedance control theory and the analysis of the influence of impedance parameters on the control performance, a variable damping impedance controller is designed. The dynamic tracking of the grasping force is realized by adjusting the damping coefficient online to modify the desired position. The simulation and experimental results show that compared with the traditional impedance control, the variable damping impedance control has a smoother tracking effect on the grasping force and its dynamic performance is significantly improved. This method can provide reference for the research of compliant grasping control of apple harvesting robot end-effector.
Substantial quantities of agri-fresh produce especially fruits and vegetables are lost and wasted at various channels and operational levels in the agri-fresh produce supply chain. This post-harvest loss and waste (PHLW) create an imbalance in demand–supply of fruits and vegetable which hinders the provision of a healthy and nutritious diet for the people. This research article aims to develop a cause-effect model by identifying and analyzing the key factors under five major operational issues (Demand forecasting, Production planning, Transportation, Inventory, and Inefficient harvesting) that leads to post-harvest loss and waste of fruits and vegetables in the agri-fresh produce supply chains (AFPSCs) in developing economies, specifically India. The empirical study evaluates sixteen key factors and is further analyzed by using the fuzzy Decision-Making Trial and Evaluation of Laboratory (F-DEMATEL) technique to understand cause-effect relationships among factors and identify significant causal factors. The results revealed a lack of coordination between production, processing, and fresh market (PHLW6), lack of seasonal demand forecasting for non-producing regions (PHLW1), poor knowledge sharing about demand and supply (PHLW2), insufficient logistics in the catchment area (PHLW10), limited availability of cold chain facility (PHLW16), improper planting and sowing time duration (PHLW5), no change in mindsets for the diversification of crops (PHLW3), and lack of specialized vehicles (PHLW8) are the eight significant causal factors which have high influence to lead the post-harvest loss and waste of fruits and vegetables in the supply chain, that needs special attention. At last, the sensitivity analysis was performed to test the robustness of the result and decrease the biases in the decision-making process. The insights of this outcome will assist in forming policies and making an operational and strategic decision for the reduction of PHLW of fruits and vegetables in the agri-fresh produce supply chain to attain sustainable development goals.
Transit vibration is a potential risk that may cause fruit deterioration. Regulating energy metabolism is recognized for attenuating fruit abiotic/abiotic stresses. To explore the role of energy metabolism in the response of fruit to vibration stress, this research investigated the effects of exogenous treatment with adenosine triphosphate (ATP) and 2,4-dinitrophenol (DNP) on fruit after simulated vibration stress. The results demonstrated that DNP treatment induced significant energy depletion, which exacerbated the adverse physiological responses induced by vibration stress. In contrast, ATP regulated higher fruit energy levels and significantly alleviated fruit quality deterioration. This is achieved by supplying direct energy substances, maintaining higher energy charges, inhibiting ethylene biosynthesis, elevating the antioxidant system, and suppressing cell oxidative damage. The results demonstrated the positive role of fruit energy metabolism response to vibration stress. Ensuring sufficient energy level may be a promising strategy for controlling vibration-induced adverse physiological responses and a potential method to maintain fruit quality.
As a common problem in snap beans, hard seed has seriously affected the large-scale industrial planting and yield of snap bean. To realize accurate, quick and non-destructive identifying the hard seeds of snap bean is of great significance to avoiding the effects of hard seeds on germination and growth. This research was based on hyperspectral imaging (HSI) to achieve accurate detection of hard seeds of snap bean. This study obtained the characteristic spectra from the hyperspectral image of a single seed, and then combined the synthetic minority over-sampling technique (SMOTE) and Tomek links to balance the numbers of hard and non-hard seed samples. The characteristic wavelengths were extracted from the average spectrum. Then the average spectrum was processed by first derivative (1D). After that, the characteristic wavelengths could be extracted using successive projections algorithm (SPA). Finally, a radial basis function-support vector machine (RBF-SVM) model was established to realize the intelligent detection of hard seeds, and the detection accuracy rate reached 89.32%. The research results showed that HSI technology could achieved accurate, fast and non-destructive testing of the hard seeds of snap bean, which is of great significance to the large-scale and standardized planting of snap bean and increase the yield per unit area.
Tomato (Lycopersicum esculentum L.) is known for its high carotenoid accumulation and has applications in nutritional products. The present experimental work was performed to estimate the fruit firmness, proximate analysis, vitamin C contents and antioxidant activity of five locally grown va rieties of tomato. Antioxidant activity of tomato fruits extract was assessed by estimation of total phenolic contents (TPC), total flavonoids contents (TFC), DPPH radical scavenging assay, inhibition of linoleic acid peroxidation and reducing power. Observed tomato varities revealed high fruit firmness (1.16-1.93kg/cm 2) and high concentration of vitamin C (30.45-36.91 mg/100g). All the selected varieties of tomatoes showed high TPC (6.75-9.63mg/100g of dry weight GAE), TFC (0.76-2.69mg/100g of dry weight) and percent inhibition of linoleic acid peroxidation (53.74-87.22%). Moreover, excellent DPPH free radical scavenging activity (IC 50 16.74-46.43µg/mL) and reducing power potential were observed. Statistical analysis revealed significant variation in antioxidant potential among different fruit varieties.
This work presents a characterisation of the fruit and the bruising caused by some common detachment methods (manual, stick, shaker comb, branch shaker) and interception methods (net or padding) in common table olive varieties. We took pictures of fruit samples inside a special device, and the images were processed to extract characteristic parameters of shape and size (number of spots, Feret diameter, circularity, colours …). Moreover, we studied the time evolution of bruising caused on the fruit by a controlled impact. Finally, we developed a system that allows synchronised rotation of the fruit with image capture to evaluate bruising on the whole volume of the fruit. Our results showed that different harvesting treatments produced differences in the average number and diameter of spots per fruit, as well as in the average area of the spots per fruit for the different varieties. Fruit colour or bruising can also serve as a control factor for computer vision characterisation, for which reason we recorded differences in the firmness of the bruised and non-bruised areas of fruit. The harvesting method that caused the highest median values of bruise index was the shaker comb, particularly for ‘Manzanilla’ with an index of 1.59% on padding compared to 0.24% for ‘Hojiblanca’. Net interception was also observed to increase the bruise index in ‘Manzanilla’ (5.85%). Bruising assessment that only considers a single photograph means that a considerable amount of bruising remains disregarded compared to the actual bruising on the whole volume of the fruit.
Background: Fruits are vulnerable to mechanical damages and physiological disorders caused by the static and dynamic forces acting on them during transportation and abiotic stresses throughout their growth and development, respectively. Identifying these defects is central to quality monitoring in the fruit processing industry. Conventionally, industries employ manual separation to segregate damaged fruits in the processing line. However, manual sorting is laborious, time-consuming, skilled labor-intensive, and destructive. Besides, it is incapable of inspecting every fruit on a fast-moving conveyor belt. Therefore, industries are looking for rapid, non-destructive, and precise technologies for the online inspection of every fruit in the process line. Scope and approach: Non-destructive techniques (NDTs) such as biospeckle, X-ray imaging, hyperspectral imaging (HSI), and thermal imaging (TI) involve noninvasive testing of sample surfaces. Earlier review articles have emphasized the applications of various NDTs in determining fruit quality and safety, but with limited focus on image processing and analysis. Therefore, this review focuses on the working principle of these NDTs in detecting fruit damages, their instrumentation, and the steps involved in image processing and analysis. The final sections highlight the limitations and future prospects pertaining to each technique. Key findings and conclusions: Biospeckle, HSI, and TI techniques can detect surface damages due to their limited light penetration depth. The HSI spectrum is useful in detecting the defects and fruit quality parameters. Active TI can detect even minor damages in the fruit, but it is not appropriate for industrial production lines. Conversely, X-ray imaging can detect fruit internal damages. The synergistic applications of these NDTs along with appropriate chemometric procedures are useful in identifying damaged fruits without human interference and evade their entry into the processing line.
In this paper, the authors present the relationship between the assumptions of ergonomics in the work of a strawberry picker and quality of picked fruit. The body posture that a person adopts while working has a significant impact on their health, working comfort, and productivity, but also on the quality of the fruit that is harvested. This paper identifies three characteristic picker positions during strawberry harvesting. A synchronized surface electromyography (sEMG) instrument together with the Tekscan® surface pressure measurement system allowed for the determination of the influence of working position on changes in the load of the picker’s musculoskeletal system and the surface pressure exerted on the fruit during manual strawberry picking, which are decisive factors for maintaining fruit quality. In addition, compression tests on whole strawberry fruit were carried out as a benchmark to evaluate and compare the maximum forces as well as the destructive pressures on the fruit. From the tests, we found that the most comfortable position of the worker’s body was determined along with the harvesting technique (position during work) that has the least negative effect on the quality of the harvested fruit. Consequently, the level of dynamic load on the worker was determined.
The paper is a continuation of the preceding research of bruising sensitivity applied to different pear varieties. This study was based on quasi-static fruit testing in compression between two plates. One part of the method is based on determining the hysteresis losses corresponding to the predetermined low level bruising. This paper contains an attempt to apply the hysteresis loss concept to dynamical impact tests, which are simpler and quicker then quasi-static ones. Moreover the impact tests are closer to the character of deformations that initiating the bruising process in real conditions. Nine pear varieties were tested quasi-statically by the method developed previously. The same varieties were tested also dynamically in a special pendulum with flat and round indentors. The results show that the dynamic test is less sensitive in determining the bruising susceptibility than the previous quasistatic one. Moreover the success of the dynamic test depends on the shape of the indentor. Acceptable results were obtained with a flat indentor in contrast to the round indentor. For the last modification of the indentor we obtained the results, from which it was practically impossible to determine the maximal value of the hysteresis losses at which no bruise spots were formed.
Kiwifruit bruise damage is a common postharvest disorder that substantially reduces fruit quality and marketability. Fruit bruise cause tissue softening and make them more susceptible to undesired agents such as diseases-inducing agents. Factors that affect kiwifruit bruise susceptibility such as impact properties and fruit properties were investigated. Two bruise prediction models were constructed for the damage susceptibility of kiwifruit (measured by absorbed energy) using multiple linear regression analyses. Kiwifruits were subjected to dynamic loading by means of a pendulum at three levels of impact. Significant effects of acoustic stiffness, temperature and the radius of curvature and some interactions on bruising were obtained at 5% probability level.
Tomatoes are a commercially important vegetable worldwide. Tomato fruit quality is substantially reduced by bruise (i.e. impact) damage. The occurrence of bruising depends on two main factors: the direct mechanical damage of the tomato, and the presence and subsequent action of unregulated cell wall-modifying enzymes. Bruising is considered to be a two-step process, in which mechanical damage occurs first and then enzymatic degradation of the affected tissue, including cell walls, takes place. This could result in a rapid enzymatic breakdown of the cell wall polysaccharides, observed as soft spots (bruises) on the fruit. To discover the bruising mechanism in tomatoes, the mechanical and biochemical properties of the pericarp tissue were investigated. At first, a logistic regression was established between impact energy and the resulting bruise damage. Results suggested that the fruit's characteristics could not be neglected. A new logistic regression was established, expressing the probability to develop bruises as a function of the energy absorbed and the specific fruit properties. In addition, a comparative biochemical analysis of the bruised and intact tissue of green, pink, light red and red tomatoes, showed that a mechanical impact results in an immediate loss of cell wall material for the riper fruit only. This study revealed that, in the case of mechanically damaged fruit, polysaccharide-digesting enzymes are responsible for the rapid breakdown of the cell wall. This action results in soft spots on the fruit. No bruises will form without the enzymatic digestion of the cell wall.
Impact testing was used to assess the variables related to bruise resistance for four peach [Prunus persica (L.) Batsch] cultivars. The effects of cultivar, ripeness, drop height, and firmness on fruit bruise incidence, bruise volume, respiration, and ethylene evolution rates of freshly harvested peaches were determined. The impact variables peak impact force, contact time, absorbed energy, and percent absorbed energy were measured at three stages of fruit ripeness and at three fruit drop heights. Each of the impact variables changed with fruit ripeness. Cultivars differed in their characteristic response to impact. Fruit impact, under the low to moderate impact energies used, had negligible effects on fruit respiration and ethylene production for the cultivars studied. Bruise incidence and volume increased with drop height and especially with advancing stage of ripeness. Under conditions we used, peach fruit bruise severity could be determined by either bruise incidence in or bruise volume of mesocarp tissue.
Strawberry is a non-climacteric fruit with a limited harvesting period. Because of high susceptibility to mechanical damage, strawberry has a small postharvest life. In this research, an experiment was designed to study the mechanical damage phenomena in strawberry during the harvest and postharvest operations together with some physical properties of strawberry. Influences of some other factors such as variety, fruit position in the box as well as box position on the truck were also investigated. Results indicated that the variety, operation stage, fruit position in the box, and box position on the truck, had significant effects on the extent of the fruits‘ mechanical damage. Maximum damage index was related to picking stage. The variety Gaviota showed more susceptibility to mechanical damage than Selva. The maximum damage occurred at the bottom rows in the boxes. Furthermore, it was observed that the higher the position of a box on the truck, the more the susceptibility of fruits would be to mechanical damage.
The effect of harvesting method on fruit quality and storability of the pink-fleshed 'Foster' grapefruits, at 18±1°C and 85%-90% r.h., was evaluated. The traditional method, using a hooked pole, was compared with an improved technique, where the picking pole was equipped with a long cloth sleeve held open by a ring for collecting the harvested fruits. The fruits were stored for three months at 18±1°C and 85%-90% r.h. Fruit samples were taken at specific times for determination of fruit quality in terms of respiration rate, total soluble solids (TSS), water loss and titratable acidity. At the termination of the experiment, the fruits were evaluated for general quality. The results showed that the improved method significantly decreased respiration rate and water loss, delayed TSS accumulation and reduced titratable acidity, resulting in improved fruit quality, reduced post-harvest losses and extended shelf-life of fruits.
Packaged tomatoes are highly perishable and tender, and are highly susceptible to mechanical damage during road transportation due to their low resistance to externally applied forces. This contributes greatly to the transit deformation leading to the breaking point under compression force. The study related mode of mechanical damage in the fruit to the strength parameters measured at break point, using compression tests. Experimental measurements of strength parameters of packaged Roma tomatoes were made to study the effects of ripeness stage, level of vibration and container type on load, deformation and stress at break of the fruit. Tomatoes harvested at three stages of ripeness: unripe (5.6 Brix %),), half-ripe (3.9 Brix %) and full-ripe (3.2 Brix %), were packed in plastic crate and raffia basket. The packaged tomatoes were subjected to three levels of vibration: non-vibrated, low-vibration (frequency 3.7 Hz) and high-vibration (frequency 6.7 Hz). These were compressed at a loading rate of 2.50 mm/min -1 in a Universal Testing Machine. Data obtained were statistically analyzed using the SPSS 110 software package. Load and stress at break decreased significantly (P=0.05) with advancing ripeness stage of the fruit. Vibration level significantly (P=0.001) lowered deformation at break. The two-factor interactions vibration*container and vibration*ripeness were significant (P=0.001 and P=0.005, respectively) on stress at break. The results obtained increase substantially our knowledge about the properties of tomato affecting mechanical damage in the tomatoes. This enables designers of tomato packaging to control mechanical damage in packaged tomatoes with due consideration for the breaking strength of the fruit.
The paper is a continuation of the preceding research of bruising sensitivity applied to different pear varieties. This study was based on quasi-static fruit testing in compression between two plates. One part of the method is based on determining the hysteresis losses corresponding to the predetermined low level bruising. This paper contains an attempt to apply the hysteresis loss concept to dynamical impact tests, which are simpler and quicker then quasi-static ones. Moreover the impact tests are closer to the character of deformations that initiating the bruising process in real conditions. Nine pear varieties were tested quasi-statically by the method developed previously. The same varieties were tested also dynamically in a special pendulum with flat and round indentors. The results show that the dynamic test is less sensitive in determining the bruising susceptibility than the previous quasi- static one. Moreover the success of the dynamic test depends on the shape of the indentor. Acceptable results were obtained with a flat indentor in contrast to the round indentor. For the last modification of the indentor we obtained the results, from which it was practically impossible to determine the maximal value of the hysteresis losses at which no bruise spots were formed.
This research was conducted to evaluate the effects of vibration frequency, vibration acceleration, packaging method, and vibration duration on the mechanical damage during apple transportation. The research was performed in 3 stages. Firstly, vibration frequency and vibration acceleration were measured on the truck-bed for determining the vibration frequency and acceleration distribution. Secondly, packaging ransmissibility and vibration frequency sensitivity for all the packaging methods used in this research were measured. Thirdly, a laboratory vibrator, which simulates the road transportation under laboratory onditions, was used to obtain some factors influencing the mechanical damage during apple transportation. According to the results measured on the truck-bed, vibration frequency values were 8.19 Hz and 12.59 Hz for 5-10 Hz and 10-15 Hz frequency intervals, respectively. Furthermore, vibration acceleration values were 0.33 g and 0.63 g for 0.25-0.50 g and 0.50-0.75 g intervals, respectively. The highest packaging transmissibility was obtained for the volume packaging method, and packaging transmissibility was at similar high levels at the vibration frequency interval of 8-9 Hz for all packaging methods. Vibration frequency, vibration acceleration, packaging method, and vibration duration, which were taken into consideration as controlled variable parameters, significantly affected the equivalent severe bruise index at the 1% level of significance. Apples in the pattern packaging method had by far the lowest bruising, and the most suitable method for transit was pattern packaging.
The susceptibility of a fruit cultivar to different types of mechanical stresses was investigated in order to set limits for intensity and type of impacts, during handling operations.The present work reports a statistical forecast model to analyse the damage susceptibility of peaches (cv Fairtime) as a function of different fruit physical and morphological variables (mass, volume, density, equatorial diameter, height), of the impact method used (drop tests performed using impact devices which were specially designed by the authors) and of variables related to the impact event (damage location on fruit). Drop heights were chosen randomly, ranging between 200 and 600 mm.The experiment was based on a multiple linear regression model (MLR) operating on the independent variables mentioned. The resulting model was shown to be highly significant (correlation coefficient of 0·82) and included among the variables related to the average damage: drop height, fruit density, pulp thickness at the point of impact and distance of the point of impact from the insertion of the peduncle. These latter two variables both present a negative coefficient which agrees with the morphological type of damage, confined to the interior of the mesocarp of the drupe very near the ligneous endocarp. Calculation using the MLR equations estimated a very low probability of slight damage (values of damage extension between 3 and 10 mm) for peaches falling as much as 400 mm.
Artificial vision systems are powerful tools for the automatic inspection of fruits and vegetables. Typical target applications of such systems include grading, quality estimation from external parameters or internal features, monitoring of fruit processes during storage or evaluation of experimental treatments. The capabilities of an artificial vision system go beyond the limited human capacity to evaluate long-term processes objectively or to appreciate events that take place outside the visible electromagnetic spectrum. Use of the ultraviolet or near-infrared spectra makes it possible to explore defects or features that the human eye is unable to see. Hyperspectral systems provide information about individual components or damage that can be perceived only at particular wavelengths and can be used as a tool to develop new computer vision systems adapted to particular objectives. In-line grading systems allow huge amounts of fruit or vegetables to be inspected individually and provide statistics about the batch. In general, artificial systems not only substitute human inspection but also improve on its capabilities. This work presents the latest developments in the application of this technology to the inspection of the internal and external quality of fruits and vegetables.
The effects of mechanical injuries on citrus fruit are not always evident. Often there is little concern about handling procedures to avoid or to reduce the forces that cause mechanical injuries. Impacts are the most common occurrence of mechanical damages in commercial operations. The objective of the present work was to evaluate the visual and chemical quality of tangerines after mechanical damage by impacts. ‘Montenegrina’ and ‘Rainha’ tangerines were submitted to different degrees of impacts and evaluated for decay and oleocelosis incidence, losses of fresh weight, total soluble solids, total titratable acidity and ascorbic acid degradation as well as for changes on epicarps’ color. Experiments with three replicates and experimental units of six fruit for each cultivar (cv. Montenegrina and cv. Rainha) were conducted in a completely randomized design. Impacts produced qualitative internal changes on tangerines, though with minor external changes. The main modifications produced by impacts on fruit are losses of citric acid and soluble solids, which increased the solids/acids ratio, and losses of ascorbic acid. ‘Montenegrina’ tangerines in comparison to ‘Rainha’ are more susceptible to the internal quality losses.
Harvest operations are currently the main source of mechanical injury of strawberry (Fragaria x ananassa Duch.). Experiments were designed to simulate conditions encountered during commercial handling. Individual fruits were subjected to impact or compression forces with similar energy to determine the sensitivity to mechanical injury. Bruise volume was used as the measurement of injury. Bruise severity increased as a function of impact energy for both impact types. However, dropped fruits had larger bruise volume than fruits submitted to pendulum impactor at the same energy level. Doubling the impact energy (0.040 to 0.083 J) increased bruise volume by 7 times (13 to 91 mm3). Fruits dropped from 380 mm (0.075 J) showed 71% greater bruise volume than those dropped from either 130 mm (0.025 J) or 200 mm (0.040 J). Compressed fruits showed higher bruise volume than other tests. Some cultivars are more susceptible to compression forces than others. 'Sweet Charlie' berries showed bruise volume 40% higher than the others cultivars when subjected to compression. Fruits subjected to impact showed bruise volume lower than the compressed fruits, indicating the possibility to be handled and graded in a packing line.
Loss of commercially valuable fruits as a result of mechanical damage continues to be an issue for postharvest operators. For most fruit types, bruising is the most common type of postharvest mechanical injury, other types of mechanical damage being abrasions and open injuries (e.g., punctures). Not only a direct effect of fruit bruising affecting the quality appreciation by the consumer exists, but bruises, even small ones, can open the way for pathogen attack (Van Zeebroeck et al., 2006). By understanding the fruit susceptibility to bruising it is possible to identify when to adopt techniques which will reduce the chances of sustaining high levels of damage, or identify cultivars that require additional care when handling (Bollen, 2005). Baritelle and Hyde (2001) suggested that reducing relative turgor through slight dehydration can reduce tissue elastic modulus, which can in turn make the fruit more “self-cushioning,” by distributing a given force over a larger area of the fruit’s curved surface. This distribution effect also occurs in padding materials for reducing the aggressiveness of packing-line machinery (see Mechanical Impacts at Harvest and After Harvest Technologies). The result is reduced impact-induced stress, and thereby reduced probability of bruise occurrence. For most fruits, bruise susceptibility increases with maturity. This is partly responsible for the early-harvesting typical of our days often criticized by many consumers. Consumers argue that nowadays a fruit is not as tasty as it was some decades ago, when it was harvested later in the season. But this is a side effect of our days, when fruits have to travel long distances from the production to the consumption centers.
Mechanical damage is an important factor of the downgrading of banana fruits during postharvest handling. Present quality ratings in the European Union take into account the percentage of peel damage due to bruising, scarring and scratching. We have studied the effects of two levels of mechanical abrasion (1 and 4 cm2 per fruit) at three relative humidity levels (50, 75 and 100% % RH) on the physiology, green life and commercial quality of banana ("Dwarf. Cavendish" cv.) fruits. The results obtained show that both levels of mechanical damage significantly affected the physiological development of the fruits (respiration and ethylene production) and had a negative incidence on final quality. Air humidity level appeared to be negatively correlated with the severity of the symptoms.
This study was carried out to determine the effect of mechanical damage on mass loss and water content in threelocular and four-locular tomato fruits by loading, storage and drying tests. Four compressibility levels, namely, 4, 8, 12 and 16%, and three loading positions were used. The results showed the compressibility and loading position had no significant effect on the water content. The mass loss was increasing with storage period at all the combinations of compressibility and loading position. The loading position had no significant effect on mass loss during storage at 4 and 8% compressibility, the mass loss at 4% was 0.63% per day and for 8% it was 8.4%. But loading position had a gradual significant effect on mass loss during storage at 12 and 16%.
The hyperspectral imaging technology was proposed to detect the subtle bruises on fruits. Apples were adopted as the experimental object. The apples' hyperspectral images between 500 nm and 900 nm wavelength were analyzed via the principal components analysis, and the feature images under 547 nm wavelength were selected to detect the bruises on apples. The asymmetric brightness of the images was eliminated with asymmetric second difference subsequently. Finally, the feature of bruise was extracted through appropriate image processing. The experimental results show that detecting subtle bruises on fruits on-line with hyperspectral imaging technology is realized and the accuracy is 88.57%.
Cell rupture in fresh-cut processing allows phenolic substrates and polyphenoloxidase (PPO), previously sequestered in different organelles, to react leading to undesirable color development. However, it is not always clear how PPO activity and phenolic content relate to tissue browning. We studied the effect of pH and phenolic substrates on PPO activity and on tissue browning in fresh-cut 'Rocha' pear, to help in the development of food additives that maximize the quality of fresh-cut pear. Substrates 4-methyl catechol, caffeic acid, (+)-catechin hydrate, catechol, chlorogenic acid, dopamine hydrochloride, and pyrogallol, were prepared in citric acid-phosphate buffer at pH values ranging from 3.0 to 8.0. PPO activity was assayed by measuring the rate of increase in absorbance at 420 nm wavelength at 25°C. Pear slices were covered with the buffered phenolic solutions and color change was assessed following 30 min at room temperature. pH optima for PPO activity depended on the phenolic substrate. Activity was optimal at pH 5.0 for catechol and 4-methylcatechol; pH 6.0 for chlorogenic acid; pH 7.0 for dopamine, caffeic acid, and catechin; and pH 8.0 for pyrogallol. The highest PPO activity at every pH tested was observed when catechol was used as substrate. Discrepancies were observed between the pH dependency of PPO activity and browning. Significant correlations were obtained between PPO activity and lightness (L*) or metric-hue difference (ΔH*) over the pH range 3.0 to 8.0 except for chlorogenic acid and 4-methylcatechol. With chlorogenic acid, the main PPO substrate in 'Rocha' pear, tissue browning was higher at pH 3.0 (higher ΔH*), but PPO activity was very low at the same pH. Similarly with the other phenolic substrates, browning at pH 3.0 was higher than the corresponding PPO activity. The pH of additives for cut pear should be corrected to reduce browning potential.
Enzymatic browning is one of the most important reactions that occur in fruits and vegetables, usually resulting in negative effects on color, taste, flavor, and nutritional value. The reaction is a consequence of phenolic compounds' oxidation by polyphenol oxidase (PPO), which triggers the generation of dark pigments. This is particularly relevant for apples, which are rich in polyphenols and highly susceptible to enzymatic browning. The objective of the present work was to quantify enzymatic browning and PPO activity and identify and quantify target polyphenols in apple [Malus ×sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] pulp in the cultivars (cvs.) Aori27, Elstar, Fuji, and Mellow at three fruit developmental stages (FDS). The enzymatic browning was quantified by tristimulus colorimetry; PPO activity was quantified by an enzyme-substrate spectrophotometric assay; phenolic compounds were determined and quantified by reverse-phase high-performance liquid chromatography-ultraviolet/visible-mass spectrometry. Enzymatic browning showed significant difference among cvs. and FDSs and interaction between both factors. PPO activity showed significant difference among cultivars and FDSs. A significant difference was evidenced for polyphenol content among cultivars and FDSs with interaction between both factors. Chlorogenic acid was the major phenolic compound in 'Aori27' and 'Mellow'. In 'Fuji', chlorogenic acid and (-)-epicatechin were the major phenolics and in 'Elstar' (-)-epicatechin and procyanidin B2 were the major phenolics at different FDSs. The enzymatic browning showed high correlation to polyphenol content in all cultivars and high correlation was observed between browning and PPO activity in 'Aori27' and 'Elstar'. The magnitude of the correlation between browning and polyphenols and PPO activity is genotype-specific. At the commercial harvest, 'Fuji' showed the highest polyphenol content and 'Aori27' showed the lowest level for enzymatic browning. Chemical names used: 3-(3,4-dihydroxycinnamoyl) quinic acid (chlorogenic acid), (-)-cis-3,3′,4′,5,7-pentahydroxyflavane (epicatechin), and cis,cis′ -4,8′-Bi(3,3′,4′,5,7-pentahydroxyflavane) (procyanidin B2).
Fruit quality is adversely affected by bruise damage. One of qualitative aspects is the detrimental effect of impact damage. In thisresearch, a pendulum device was developed to study fruit mechanical damage. The bruise prediction models were constructed to apple fruit damage susceptibility (measured by bruise volume) using multiple linear regression analyses. Bruise sensitivity was determined by both impact characteristics (peak contact force or impact energy) and some fruit properties (temperature, ripeness and radius of curvature). Apples were subjected to dynamic loading by means of a pendulum at three impact levels (0.048, 0.14, 0.26 J). Significant effects of acoustic stiffness, temperature and the radius of curvature and some interactions on bruising were obtained 5% probability level with determination coefficient (R2) of 0.88 and 0.95 for models 1 and 2, respectively. It was concluded that bruise damage of apple fruit will be reduced by increasing temperature and radius of curvature and also by declining acoustic stiffness.
Solo' papaya (Carica papaya L.) fruit removed at different points from a commercial packing house showed that skin injury due to mechanical damage increased as fruit moved through the handling system. The occurrence of “green islands” -areas of skin that remain green and sunken when the fruit was fully ripe-apparently were induced by mechanical injury. Skin injury was seen in fruit samples in contact with the sides of field bins, but not in fruit taken from the center of the bins. Bruise-free fruit at different stages of ripeness (5% to 50% yellow) were dropped from heights of 0 to 100 cm onto a smooth steel plate to simulate drops and injury incurred during commercial handling. No skin injury occurred, although riper fruit showed internal injury when dropped from higher than 75 cm. Fruit (10% to 15% yellow) dropped onto sandpaper from a height of 10 cm had skin injury symptoms similar to those seen on fruit from the commercial handling system. These results suggest that abrasion and puncture injury were more important than impact injury for papaya fruit. Heating fruit at 48C for ≈6 hours or until fruit core temperature (FCT) reached 47.5C aggravated the severity of skin injury. Delays in the application of heat treatment from dropping did not reduce the severity of skin injury significantly, except for fruit heated 24 hours after dropping. Waxing fruit alleviated the severity of skin injury, whether applied before or after the heat treatment. Skin injury to papaya was caused by abrasion and puncture damage-not impact-and increased during postharvest handling of the fruit. The injury was associated mainly with fruit hitting the walls of wooden bins-bin liners may reduce this injury.
In this study, factors affecting the rupture probability of tomato fruits were investigated. The experiments were carried out at five compressibility levels (4%, 8%, 12%, 16% and 20%), four loading positions and two probe shapes. The fruit size, shape and mass did not have a significant effect on the rupture probability. The compressibility was the most important independent variable affecting the rupture probability of tomato fruits in the model. The rupture probability of quadrilocular tomato fruit loaded from the cross-wall tissue was the highest, and the odds of being ruptured was 14.5 times higher for quadrilocular tomato fruit loaded from the cross-wall tissue compared to the locular tissue. The curved probe was much more sensitive than the plate probe for rupturing of tomato fruits during the compression tests. It is clear that these investigated factors need to be considered carefully in design and control of tomato harvesting equipment.
Machine harvested and hand harvested mature green tomatoes were compared for physical damage. The experiments showed that harvesting and handling processes per se have a negative effect on fruit quality, but that the quality of machine-harvested fruit can be comparable to that obtained from commercial hand-harvest situations. While the opportunity for puncture injury to occur is greater when the fruits are detached and handled with stems, the practical consequences of this depend on the variety. It would be desirable to eliminate the stems from the fruit as early as possible in the handling process. It may be sufficient, however, to accomplish this task in the packing shed if the variety can be characterized as easy to de-stem, exhibiting less than 40% stems after passing over the shaker.
Each year a majority of the U.S. apple crop is transported in bulk bins on semi-trailers and trucks from the orchard to a storage facility or central packing house. During the transportation process, mechanical damage such as bruises, abrasions, cuts, and punctures can occur, causing a decrease in fruit grade. Tests were conducted in Michigan to identify the magnitude of damage incurred by apples in bulk bins during semi-trailer transportation on a rough interstate highway. Five bulk bin designs (two hardwood, one plywood, and two plastic), two trailer suspension systems (steel-spring and air-cushion), and two trip distances [55 and 110 km (34 and 68 mile)] were evaluated. Damage-free apples were used in all tests and accumulated damage was measured. Test fruit positioned in the middle of each bin had similar bruise and abrasion damage levels regardless of the bin design, suspension system, or trip distance. Abrasion damage on the sidewall test apples varied among bin design, suspension system, and trip distance. Abrasion damage on sidewall test fruit was significantly less on the air-cushion system. The plastic bins had much less abrasion damage on the sidewall test fruit than did the hardwood and plywood bins. The range of abrasion damage on the sidewall test apples was 0.6 to 65%. Sidewall fruit grade ranged from 71.3 to 100.0% U.S. Extra Fancy. Vibration data collected for both trailer suspension systems was used to develop a power spectral density representation of the load input vibration. A 60-min trip simulation on a computerized vibration table was conducted for the steel-spring suspension system using the five different designs of bulk bins. The percentage of apples having abrasion damage was comparable to levels from actual highway tests. Overall, the U.S. apple industry can maintain higher apple quality if bulk apples are transported in plastic bins of these designs and on semi-trailers having air-cushion suspension.
RESULTS of impact and compression tests on Chojuro, Twentieth Century, Tsu Li, and Ya Li varieties of Asian pears indicate that Chojuro pears are the firmest and most resistant to mechanical damage. At the time of harvest, Tsu Li and Ya Li pears could resist mechanical damage nearly as well as Chojuro pears, but they become more susceptible to bruising in cold storage. Twentieth Century pears are most sensitive to impact and compression bruising. Increased time in the ripening room produces more softening and increased bruise resistance of Chojuro and Twentieth Century pears than of Tsu Li and Ya Li pears.
In this study, geometrical properties such as linear dimensions, sphericity, mass of fruit, projected area, surface area, true density, volume, hydrodynamic properties in water namely terminal velocity, drag force and buoyant force and bruising characteristics like as bruise area and bruise volume of two varieties of table olive fruit were determined. The values of length, width, geometric mean diameter, sphericity, mass of fruit, surface area, volume, gravitational force and buoyant force except projected area and true density terminal velocity and drag force were statistically significant between two varieties. The greatest values of bruise area and bruise volume were obtained with the stainless steel for both varieties.
Mechanical damage is the major cause of postharvest losses and among the perishable crops tomato is susceptible to mechanical injury considrably. By conducting a series of impact tests (from 0.18 to 2.88 J) by a pendulum impact apparatus, occurance of damage, in the form of rupture and latent damage, were investigated as affected by stages of ripening (pink, ripening, maturity and Plasmolism) and variety (Super Bta and Petoerly-ch). According to the results at any treatment of variety and stage of ripeness, falling of tomatoes from maximum height of 59 cm does not occure any rupture in fruit, causes injury in tomatos as degradation as a kind of latent damage. However, the minimum energy required for rupture injury was about 1.58 J and 0.84 J in first and third stages of ripenening, respectively. According to the results of ANOVA, there are no differences between two varieties based on rupture injury, whereas, impact energy and especially stage of ripeness had significant effect on all types of mechanical damage in tomato fruit. Also, the results showed that the severity and rate of latent damage increase progressively, through 24 to 72 hours of storage of fruits in natural conditions. Ripenenning stage is the major factor affect severity of latent damage through 72 hours after impact.