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PH—Postharvest Technology: Surface Gloss and Weight of Eggplant during Storage
Abstract
Surface gloss and weight loss are two important parameters to judge the freshness of eggplant. Data were collected in order to develop some quick and reliable instrumental methods to determine these. Surface gloss and weight loss of eggplant stored for 0–96 h at 80–84% relative humidity and 20°C temperature were determined using a computerized spectral radiometer and a precision electronic balance, respectively. The surface gloss was quantified in terms of gloss index, and a relationship between weight and gloss index during storage of eggplant was established. Gloss index and weight both decreased quadratically with storage period. Major changes were observed in the first 48 h of storage. Weight and gloss index of eggplant during storage were found to be correlated linearly.
... There are a number of factors which influence the radiation and exact color that one perceives. Jha et al. had developed a spectral radiometer that is used in determining the freshness of the eggplant based on the surface gloss and the weight at the time of storage [162]. The Table 13.6 reports various studies regarding the non-destructive techniques implemented in vegetables [79]. ...
Food safety and quality are of utmost importance for consumers, suppliers, and regulators. The methodologies for determining the food quality are majorly classified as destructive and non-destructive techniques. The destructive techniques used for determining the food quality are labor-intensive, time-consuming, cost-intensive, and biased, while non-destructive techniques are gaining popularity due to ease of operation, reliability, and real-time results. Non-destructive methods play an important role in food industries due to its inherent nature. Both external and internal quality can be determined by non-destructive methods and rapidly help in sorting the superior quality of food products. Currently, different non-destructive methods such as electromagnetic, optical, mechanical, and dynamic are gaining popularity due to ease of operation, reliability, and faster turnover. The major drawback of non-destructive methods is the high equipment cost and the use of various instruments to analyze various parameters. But even then, these methods help to ensure customer satisfaction of products as it helps in providing good quality products without rupturing it. This chapter gives broader concept of non-destructive method used in quality assessment of food products and their applications for food evaluation and quality.
... Recently, a chemical kit for qualitative detection of detergent, indicating synthetic milk adulteration has been developed by National Dairy Research Institute, Karnal, India (NDRI, 2015) but it does not quantify the adulterants and takes more time. Spectroscopy is an emerging powerful technique for fast, accurate, often non-destructive analyses of chemical compo- nents in complex food matrices (Jaiswal, Jha, & Bharadwaj, 2012;Jaiswal et al., 2014;Jha, 2007;Jha & Gunasekaran, 2010;Jha, Jaiswal, Grewal, Gupta, & Bharadwaj, 2015;Jha & Matsuoka, 2004;Jha, Matsuoka, & Miyauchi, 2002;Narsaiah, Jha, Bhardwaj, Sharma, & Kumar, 2012). Goni and Alonso (2000) have earlier reviewed use of spectroscopic techniques for studying the mem- brane solubilization, reconstitution and permeabilization proper- ties of detergents. ...
Adulteration of milk to gain economic benefit is rampant. Addition of detergent in milk can cause food poisoning and other complications. Fourier Transform Infrared spectroscopy was evaluated as rapid method for detection and quantification of anionic detergent (lissapol) in milk. Spectra of pure and artificially adulterated milk (0.2-2.0% detergent) samples revealed clear differences in wavenumber range of 4000-500 cm⁻¹. The apparent variations observed in region of 1600-995 and 3040-2851 cm⁻¹ corresponds to absorption frequencies of common constituents of detergent (linear alkyl benzene sulphonate). Principal component analysis showed discrete clustering of samples based on level of detergent (p ⩽ 0.05) in milk. The classification efficiency for test samples were recorded to be >93% using Soft Independent Modeling of Class Analogy approach. Maximum coefficient of determination for prediction of detergent was 0.94 for calibration and 0.93 for validation, using partial least square regression in wavenumber combination of 1086-1056, 1343-1333, 1507-1456, 3040-2851 cm⁻¹.
... 1-MCP treated eggplants maintained higher gloss than control fruit (Fig. 1B). Jha et al. (2002) found a negative linear correlation between eggplant fruit dehydration and surface gloss. Dehydration symptoms were clearly visible in control fruit after 21 d at 10 • C and 2 d at 20 • C (21 + 2 d) (Fig. 1B). ...
Ethylene action can be counteracted by 1-methylcyclopropene (1-MCP), which has been used during postharvest storage to maintain quality. In this work, we evaluated the effect of 1-MCP treatments on eggplant quality and phenolic metabolism during refrigerated storage. Eggplants (cv. Lucía) were harvested at commercial maturity, treated with 1-MCP (1 μL/L, 12 h at 20 °C), stored at 10 °C for 21 d and subsequently held at 20 °C for 2 d. Corresponding controls were stored at 10 °C and then transferred to 20 °C for 2 d. During storage calyx color, damage and chlorophyll content, fruit weight loss and firmness, pulp sugar content, acidity, browning and total phenolics were measured. In addition, polyphenol oxidase (PPO), pyrogallol peroxidase (POD), and phenylalanine ammonia-lyase (PAL) activities were evaluated. Fruit calyxes showed reduced damage and remained greener in 1-MCP treated than in control fruit. 1-MCP treated eggplants showed lower weight loss. Pulp browning was clearly prevented as a consequence of 1-MCP exposure, and this was associated with delayed senescence, lower accumulation of total phenolics and reduced activity of PAL. The activity of the enzymes PPO and POD involved in the oxidation of phenolics compounds was also decreased in 1-MCP treated fruit. Results suggest that 1-MCP treatments delay senescence, prevent browning and are beneficial to complement low temperature storage and maintain quality of non-climacteric eggplant fruit.
... The physical attributes of fruits such as weight, peel content, length, seed, pulp, gloss are highly variable with variety [11]. Mango fruits contain protective nutrients and are rich in minerals such as magnesium, potassium, sulphur, phosphorus and vitamin A, C and D. Good mango varieties contain 20 % of total soluble sugars [22]. ...
Mango cultivars are presently identified phenotypically. In the present study, near-infrared spectroscopy in the wavelength range of 1,200–2,200 nm, in combination with chemometrics was evaluated for the purpose. Principal component analysis and partial least square (PLS) discriminate analysis were applied using characteristic variables as 0 and 1 for cv Alphonso and Banganapalli, respectively, in one group and for Dasheri and Malda, respectively, in the other group. PLS was carried out with and without pre-processing of spectral data. Wavelength range of 1,600–1,674 nm was found to be suitable for the classification of Alphonso and Banganapalli after detrending of data, while Dasheri and Malda could be classified in the wavelength range 1,200–2,200 nm after computing Norris-Gap derivative. Alphonso–Banganapalli could be differentiated from each other with 99 % accuracy, whereas, accuracy for Dasheri and Malda was about 94 at 5 % level of significance.
... In spectroscopy, infrared spectroscopy (IR) methods have been successfully applied for detecting adulterants in a wide range of food as valuable and powerful tools due to instrumentation and combination with machine learning methods (Soyeurt et al., 2006;Rodriguez-Saona and Allendorf, 2011;Jawaid et al., 2013;Santos et al., 2013;Mabood et al., 2017;Oliveira et al., 2019;Stöbener et al., 2019;Hosseini et al., 2021). The advantages of IR spectroscopy such as rapid, minimal, or no sample preparation, simplicity, non-invasive, high performance, on-or inline measurements, and ability to identify certain functional groups have evaluated physical and chemical parameters simultaneously (Jha et al., 2002;Jha and Matsuoka, 2004;Narsaiah et al., 2012;Jaiswal et al., 2014;Jha et al., 2016;Jaiswal et al., 2017;Salleh et al., 2019;Kaavya et al., 2020). ...
The monitoring of milk and milk-based products are crucial in the dairy industry because of their global consumption, fraudulent practice applied to mask the quality parameters for gaining more profit. Non-destructive near-infrared (NIR) spectroscopy and machine learning (ML) methods like interval partial least squares (iPLS), principal components analysis (PCA), and soft independent modeling of class analogy (SIMCA) were used to classify and discriminate pure milk samples from adulterated with an anionic surfactant. The surfactant’s model was sodium dodecylbenzene sulfate (SDBS) in different concentrations (1.94-19.4 gkg⁻¹). ML models were assessed by sensitivity, specificity and efficiency rates as classification figures of merit. As a result, iPLS regression method based on standard normal variate (SNV) pre-processed spectra provided better performance compared to partial least squares (PLS) regression with a full-spectrum dataset. The root mean square error of cross-validation (RMSECV) was 0.123 and 0.135 for the iPLS and full-spectrum models, respectively. PCA as a qualitative grouping analysis demonstrated separate clusters of samples in terms of their concentration level of SDBS. For the iPLS dataset in SIMCA model, all classification figures of merit were recorded 100% for pure milk samples. In contrast, the average sensitivity, specificity and efficiency rates were 97.6%, 93%, and 94.9% for adulterated samples.
... Eggplant (Solanum melongena L.) is a common vegetable available in retail outlets worldwide but has a very limited shelf life for freshness (1)(2)(3). It is also known as aubergine, guinea squash or brinjal and a good source of vitamins and minerals (particularly iron) making its total nutritional value comparable with tomato (4). ...
The effects of active packaging on the surface stiffness, mass, volume, density and weight changes of fresh as well as stored eggplant were studied at 11 and 25°C for 10 days with active packaging material Type 1 and 2 and control. Mass, volume, and surface stiffness of eggplant decreased linearly throughout the storage period regardless of storage conditions; while the mass density showed a reverse trend in the case of 11°C storage. Reduction rate of mass, mass density and weight was observed minimum at 25°C storage temperature with active packaging Type 1. The weight of eggplant decreased at a higher rate in the initial 4 days compared to that in the later period of storage regardless of storage temperature and type of packaging.
... Attempts to include the spectral information of the reflected light have been also made. Jha et al. used a spectroradiometer to record the light reflected by the curved surface of eggplants illuminated by a halogen light source (Jha, Matsuoka, et al. 2002). The ratio between reflected and incident light at each wavelength was used to define a spectral gloss index which, when integrated in the visible range, gave the gloss index of the sample. ...
... In the case of PPB condition and the control samples, the water derived from eggplant respiration was removed by evaporation from the fruit surface, promoting them weight loss. Decreasing of eggplants weight during storage was also reported by Jha et al. (2002) and Concellón et al. (2012) Concellón et al. (2007) and Amanullah et al. (2016). According to this, the pH value of eggplant fruits increases with storage temperature (Amanullah et al., 2016 andConcellón et al., 2007). ...
High demand for fresh fruit and vegetables requires the implementation of techniques to extend the shelf life of these highly perishable products. A widely used method for this purpose is the refrigeration; however, it is known that most of the vegetables preserved in this way evidence chilling injury signs during storage. Eggplants cv C029 recently harvested were stored at 13°C packed into low-density polyethylene bags either with perforations (PPB), vacuum packaged (VPB), or unpacked during 5, 10, 15 and 20 days to evaluate the effect of chilling on physicochemical characteristics and visual appearance. Unpacked Eggplants presented remarkable chilling injury symptoms, losing its commercial quality before 10d of storage. Fruit stored in VPB showed discoloration affecting visual appearance but maintains the phenolic compounds and avoided pulp and seeds browning. Eggplants packed in PPB showed the best results in this work, preserving overall characteristics during 15d.
... Table 2 shows the results of precooling treatments and different storage conditions on physiological loss in weight of tomato at the end of 12 days storage. Weight loss of fresh tomatoes is primarily due to transpiration and respiration (Jha and Matsuoka 2002). PLW was lower under low temperature storage than the ambient storage at the end of shelf life. ...
A comparative study was carried out to determine the efficacy of different precooling treatments at three different cooling media temperatures on the shelf life of tomato fruit (cv. Narendra-2) when stored under low (13°C) and ambient temperature. The precooling with chilled water dipping took least time (<0.33 h) compared to hydrocooling (<0.41 h) and forced air cooling (<1.45 h) to remove field heat of tomato fruit. The maximum increase in shelf life up to 18 days was observed for treated fruit as compared to control under low temperature storage. For samples treated at 4°C, forced air cooling had a maximum shelf life of 27 days under ambient storage compared to control (18 days). The stored samples were periodically analyzed for various physico-chemical parameters. After 12 days storage maximum physiological loss in weight 7.68%, spoilage 31.08%, firmness 468.64 N, total soluble solids 4.4%, titratable acidity 0.37% and lycopene content 4.20 mg/100g was observed.
... In the case of PPB condition and the control samples, the water derived from eggplant respiration was removed by evaporation from the fruit surface, promoting them weight loss. Decreasing of eggplants weight during storage was also reported by Jha et al. (2002) and Concellón et al. (2012) Concellón et al. (2007) and Amanullah et al. (2016). According to this, the pH value of eggplant fruits increases with storage temperature (Amanullah et al., 2016 andConcellón et al., 2007). ...
High demand for fresh fruit and vegetables requires the implementation of techniques to extend the shelf life of these products, which are highly perishable. A widely used method for this purpose is the refrigeration; however, it is known that the most of vegetables preserved in this way evidence chilling injury signs during storage. Eggplants cv C029 recently harvested were stored at 13°C packed into low density polyethylene bags either with perforations (PPB), vacuum packaged (VPB) or unpacked during 5, 10, 15 and 20 days in order to evaluate the effect of chilling on physicochemical characteristics and visual appearance. Unpacked Eggplants presented remarkable chilling injury symptoms, losing its commercial quality before 10d of storage. Fruit stored in VPB showed discoloration affecting visual appearance but maintains the phenolic compounds and avoided pulp and seeds browning. Eggplants packed in PPB showed the best results in this work, preserving overall characteristics during 15d.
This study was carried out to analyze the physicochemical properties according to salting methods of eggplants exported mainly to Japan. Moisture contents of Chukyang and Shikibu were decreased after 3 days of salting regardless of salting methods. The decrease of moisture content in mixed treatment of rice husk and salt was higher than that of salt treatment after 7 days of salting. Ash contents of Chukyang and Shikibu were increased according to extended salting time regardless of salting methods. The Brix of Chukyang and Shikibu without salting were 4.0^{\circ}brix\;and\;5.0^{\circ}brix, respectively, and were increased according to extended salting time regardless of kinds and salting methods. pH of Chukyang and Shikibu without salting were 6.04 and 6.00, respectively. Extended the salting time from 0 to 7 days did not result in a pH change. Reducing sugar contents of Chukyang and Shikibu were increased according to extended salting time, the increase of reducing sugar content in mixed treatment of rice husk and salt was higher than that of salt treatment during salting. Soluble protein contents of Chukyang and Shikibu without salting were 1.40 g and 1.85 g, respectively. Extended the salting time from 0 to 7 days resulted in gradual increase in soluble protein content of Chukyang and Shikibu.
Digital colour imaging (DCI) was applied in this study as a novel approach for assessing the mixture quality of binary food powder mixes. Three different binary powder mixes with different coloured ingredients [salt, paprika, black pepper and onion] were investigated using a commercially available system called DigiEye. The coordinates of CIELAB colour space were used to describe the colour of the samples. The sample colour variance was used as a measure of mixture quality. The results showed that DCI has potential for assessing the mixture quality of binary food powder mixes, provided that colour difference between the powders can be measured. The ability to assess mixture quality decreases as the colour difference between the components in the mix decreases. Furthermore, scale of scrutiny and composition also influence the capability of the method.
The physico-chemical parameters (pH, mechanical firmness and vitamin C) and sensory parameters of grafted and ungrafted eggplant plants were studied in relation to storage time (up to 17 days at 10 °C). Eggplant plants of cultivar ‘Tsakoniki’ were grafted on Solanum torvum and S. sisymbriifolium rootstocks in order to avoid the soil borne disease caused by Verticillium dahliae. The fruits were stored under modified atmosphere packaging (MAP). Vitamin C was negatively affected by grafting it storage, while MAP prolonged the shelf life. Although pH was not affected by grafting but was positively affected by MAP. Flesh firmness was negatively affected by grafting and reduced over storage, but positively affected by MAP. Sensory analysis showed higher ratings of fruits from ungrafted plants for sweetness, acceptance and hardness whereas no difference was detected for overall acceptance. Fruits stored under MAP were better maintained compared with those stored in air.
Postharvest damage in fresh mangosteens at wholesale level in Thailand was investigated from April to October 2004. A total of 37.1% of the production yield was rendered inedible by damage during this period; damages included fruit cracking, hardened rinds, rough surfaces, translucent flesh, gummosis and decay. This study focused on a method of predicting damage based on the color of the skin of the affected mangosteen. As a first step, diameter, height, weight, and volume of large, medium, small, and undersize mangosteens were measured. The term, dimension ratio, was introduced as a sizing parameter identifying conventional trade size. The coefficient of static friction of the glossy- and rough-surface mangosteens on plexiglass, plywood, and galvanized steel sheet varied from 0.31 to 0.46. The color of sound and defective fruits was measured in terms of their tristimulus values X, Y, and Z. The corresponding chromaticity coordinates of a mangosteen, x and z, depended on the maturity stage of the fruit while y depended on the type of fruit surface. A ratio was proposed to test the accuracy of predicting internal defects from the color variation between two spots on the surface of the same fruit. The highest percentage of correct prediction was 67.4% with a color ratio of X1 (pink blush color on yellow ground color) to X2 (pink color) that was greater than 1.25.
The king of fruits "Mango" (Mangifera indica L.) is very nutritious and rich in carotenes. India produces about 50% of the total world's mango. Many researchers have reported the maturity indices and quality parameters for determination of harvesting time and eating quality. The methods currently used for determination of quality of mango are mostly based on the biochemical analysis, which leads to destruction of the fruits. Numerous works are being carried out to explore some non-destructive methods such as Near Infrared (NIR), Nuclear Magnetic Resonance (NMR), X-ray and Computed Tomography (CT), electronic nose, machine vision and ultrasound for quality determination of fruits. This paper deals with some recent work reported on quality parameters, harvesting and post-harvest treatments in relation to quality of mango fruits and reviews on some of the potential non-destructive techniques that can be explored for quality determination of mango cultivars.
Sensory evaluation is the ideal tool for shelf-life determination. With the objective to develop an easy shelf-life indicator, color (L*, a*, b*, chroma and hue angle), total soluble solids (TSS), firmness (F), pH, acidity, and the sensory attributes of appearance, brightness, browning, odor, flavor, texture, color, acidity and sweetness were evaluated in fresh cut mangoes (FCM) stored at 5, 10, 15 and 20 °C. Overall acceptability was evaluated by consumers. Correlation analysis between sensory attributes and physicochemical variables was carried out. Physicochemical cut-off points based on sensory attributes and consumer acceptability was obtained by regression analysis and utilized to estimate FCM shelf-life by kinetic models fitted to each variable. The validation of the model was done by comparing the shelf life estimated by kinetic models and consumers. It was recorded large correlations between appearance, brightness, and color with L*; appearance and color with chroma and hue angle; sweetness and flavor with TSS, and between F and texture. The shelf life estimated based on consumer using a 9 point hedonic scale was in the range of 10–12, 2.3–2.6, 1.3–1.5 and 1.0–1.1 days for 5, 10, 15 and 20 °C. It was recorded large correlation coefficients between the shelf life estimated by consumer acceptability scores and physicochemical variables. Kinetic models based on physicochemical variables showed a tendency to overestimate the shelf life as compared with the models bases on the sensory attributes. It was concluded that physicochemical variables can be used as a tool to estimate the FCM shelf life.
Non-destructive physical tests are recent trends for quality evaluation of fruits and vegetables. Information on post-harvest variations in electrical resistance, gloss and weight are needed to develop new instruments for this purpose. Surface electrical resistance, surface gloss and weight of eggplant (Solanum melongena L.) fruits stored for 0–96h at 20°C temperature and 80–84% relative humidity were measured using a galvanometer, spectral radiometer and a precision electronic balance, respectively. Relationships of surface electrical resistance with gloss and weight loss during storage were also investigated. The surface electrical resistance increased quadratically with increase in storage period and with decrease in both weight and gloss index of eggplant during storage.
During this study the postharvest damages of fresh mangosteen at wholesale level in Thailand were investigated from April to October 2004. Damages included fruit cracking, hard rind, rough surface, translucent flesh, gummosis, and decay. Total percentage of all damages that made fruit inedible was 43.3 % of production yield. Weight, volume, and dimension of large, medium, small, and undersized mangosteens were measured. The term of dimension ratio was introduced as a sizing parameter compared to the conventional trade parameter. The coefficient of static friction was also determined. This coefficient for gloss and rough surface mangosteens on plexiglass, plywood, and galvanized iron steel varied from 0.31 to 0.46. Color of sound and defective fruits was measured in terms of tristimulus values, X, Y, and Z. It was observed that the corresponding chromaticity coordinates, x and z for mangosteens depend on their maturity stage whiles depends on the type of fruit surface. A color ratio term is proposed to be used as a nondestructive technique for detecting internal defects of mangosteens. The highest percentage of correct prediction was found at the color ratio X1/X2> 1.25 at 67.4 %
Nondestructive way of determining the food quality is the need of the hour. Till now major methods such as colour measurements and their modeling; machine vision systems; X-ray, CT and MRI; NIR spectroscopy; electronic nose and tongue; and ultrasonic technology have been discussed in detail. These techniques, in general, are considered to be sophisticated and costly, and therefore probably are not being adopted as fast as it should be. I am however of the reverse opinion. While going through these techniques, it has been seen that majority of quality parameters have been measured and correlated with the signals obtained using different equipment.
Currently, destructive techniques can be employed to evaluate the internal attributes of fresh fruits, vegetables and nuts. However, clearly not all produce can be evaluated. Thus, there is a need to develop an in vivo non-destructive technique able to assess fresh agricultural commodity internal components, especially disorders. In this study, medical grade computed tomography (CT) was used to obtain transversal two-dimensional (2D) images from several fresh agricultural product phenomena. CT scanning was performed by placing and securing numbered samples onto a whole polyethylene sheet, placed on the CT scanner table. Phenomena included the internal decay of chestnuts (Castanea spp.), internal defects in pickling cucumbers (Cucumis sativus), translucency disorder in pineapples (Ananas comosus), pit presence in tart cherries (Prunus cerasus var. Montmorency) and plum curculio (Conotrachelus nenuphar) infestation of tart cherries. In addition, an ultrafast X-ray CT scanner was also used to visualise internal characteristics of fresh chestnuts. Chestnuts were labelled and packed in a thin plastic hose, which was pulled through the scanning plane. The 2D CT X-ray images and post-processing three-dimensional CT image reconstruction indicate that CT can be used as an accurate in vivo insight of fresh intact agricultural products. Results suggest that there is a potential for non-destructive inline sorting of the internal quality of several agricultural products. The long-term objective is that the fresh and processing product industries will then be able to detect internal quality attributes of fresh agricultural commodities, at a relatively early stage, after validation under commercial conditions.
X-ray computed tomography (CT) is an effective noninvasive tool to visualize fresh agricultural commodities’ internal components and quality attributes, including those of chestnuts (Castanea spp). There is no procedure to automatically, effectively and efficiently classify fresh commodities from a continuous inline flow through a CT system. If the information obtained by CT scanning of fresh agricultural commodities is to be used in an industrial application (e.g. inline sorting), automated interpretation of CT images is essential. For this purpose, an image analysis method (algorithm) for the automatic classification of CT images obtained from 2848 fresh chestnuts (cv. ‘Colossal’ and ‘Chinese seedlings’), during the harvesting years from 2009 to 2012, was developed and tested. Classification accuracy was evaluated by comparing the classes obtained from six CT images per chestnut to their internal quality assessment. An experienced human rater performed internal quality assessment by visually and invasively rating fresh chestnut internal decay severity (quality) into 5-, 3- and 2-classes.
After CT image preprocessing, cropping and segmentation, 1194 grayscale intensity and textural features were extracted from six resultant CT images per sample. Relevant features were selected using a sequential forward selection algorithm with the Fisher discriminant objective function. 86, 155 and 126 features were effective in designing a quadratic discriminant classifier with a 4-fold cross-validation with a performance accuracy of 85.9%, 91.2% and 96.1% for 5, 3 and 2 classes, respectively. This method is accurate and objective in determining fresh chestnut internal quality, and the methodology is applicable to automatic noninvasive inline CT sorting system development.
Visually assessed appearance is undoubtedly of great importance to the selection of fruit by the consumer at the point of sale while the food supply chain also heavily relies on colour assessment methodologies for the determination of product quality. The use of printed colour charts to assess the ripening stages of fruits (i.e., banana ripeness charts) and/or vegetables is common in the fresh produce supply chain, even though they have limitations. However, the development of a more reliable and an objective instrumental method is necessary to describe fruit ripeness using set colour appearance parameters rather than subjective evaluations based on colour charts. In this article, we report a novel digital imaging methodology that could be used by the fresh produce industry to estimate the ripening stages of bananas more accurately. © 2012 Wiley Periodicals, Inc. Col Res Appl, 38, 364–374, 2013
This study was designed to investigate the Quality of salted eggplants with mixed rice bran and salt during 7 days at for the quality improvement and arrangement of eggplants exported to Japan. It was carried out to analyze the changes of the color, organic acids, amino acids and minerals during salting. L and b values of eggplants were decreased, and a value of eggplants was increased during salting. Organic acids such as acetic, citric, lactic, malic, and succinic acids were analyzed from eggplants. The content of acetic and malic acid were decreased during salting, but citric and succinic acid contents were increased The major amino acids were alanine, glycine, valine and leucine. Total amino acid content of Chukyang was decreased but that of Shikibu was not changed during salting. The major free amino acid was -aminobutyric acid and contents of -aminoadipic acid and -aminobutyric acid were increased during salting. Sodium and potassium were major minerals of eggplants. Sodium, potassium and magnesium were increased during salting.
This study was carried out to investigate the changes in components of salted eggplant (chukyang) during storage. The contents of total and reducing sugar were decreased during storage, and the tendency was lower in the salted eggplants of vacuum packing storage than in the salted eggplants of rice bran immersion storage. The organic acids of salted eggplants were acetic acid, citric acid, lactic acid, and malic acid. And acetic and malic acid contents were much higher than the others. The content of acetic acid was increased during storage, but malic acid was decreased. Major amino acids of eggplants were valine, aspartic acid, glutamic acid, glycine, and alanine. The content of total amino acid was 1,488.18 mg/100 g in eggplant packed vacuum film at 20 days of storage, and higher than those in fresh eggplant. The content of total amino acid in eggplant immersed in wet rice bran was 745.42 mg/100 g at 20 days of storage, and decreased during storage. The contents of aspartic acid, alanine, cystine, and proline in free amino acids of salted eggplants were higher than other amino acids. The contents of phosphoserine, taurine, -aminoisobutyric acid and hydroxyproline were higher than others. Posphoserine content was decreased during storage, but -aminoisobutyric acid content was increased during storage.
Physico-chemical characteristics, viz., total soluble solids (TSS), pH, dry matter (DM) and overall acceptability scores (OA) of nine major Indian mango cultivars at different harvesting stages were studied during natural ripening. Mangoes were kept in a single layer at ambient room conditions (26-38°C, RH 60-70%) for ten days and were taken randomly at an interval of two days for quality assessment. Parameters like TSS and pulp pH showed significant increase while, DM declined significantly with storage period. The early harvested mangoes did not ripen well with OA score of less than 6 except Alphanso from Maharashtra, whereas; mangoes harvested at mid and late stages ripened well and resulted into higher sensory scores. Statistically significant scores were observed in late harvested mangoes. There was significant variation in OA scores of early, mid and late harvested mangoes.
Evaporative cooling is an efficient and economical means for reducing temperature and increasing the relative humidity of an enclosure, and has been extensively tried for enhancing the shelf life of horticultural produce. The evaporative cooled storage structure has proved to be useful for short term, on-farm storage of fruits and vegetables in hot and dry regions. Cooling performance of this structure depends on the construction materials used. The effect of various types of bricks and cooler pads on absorption and evaporation of water from their surfaces, at afferent ranges of temperature and relative humidity (RH) were studied to select the suitable one. The clay and sand lime brick and cooler pads made of portal' wood shavings were found to be most effective and economical for design of evaporatively cooled storage structures.
Factors affecting the composition, quality and storage life of fresh tomatoes (Lycopersicon esculentum Mill.), peppers (Capsicum annuum L.) and eggplants (Solanum melongena L.) as well as fresh-cut (minimally processed) produce are discussed both in the light of European Union (EU) quality standards and on the basis of recent research findings. The fruit of all three Solanaceous species are highly perishable and careful manipulation of the storage conditions is required in order to preserve quality at an acceptable level. The stage of harvest and the storage techniques applied relate largely to the climacteric or non-climacteric nature of the fruit, and the role of ethylene in fruit ripening is discussed. Tomato, pepper and eggplant fruit are all rich sources of antioxidants, and these substances are implicated in the prevention of cardiovascular and other human diseases. Apart from epidemiological studies on the relationship between antioxidant intake and disease occurrence, several studies have concentrated on the changes in antioxidant levels during fruit growth and maturation, as well as on the fate of antioxidants during storage and processing. The fruit of all three species are susceptible to chilling injury and this susceptibility restricts the temperature at which storage can be carried out. However, a number of studies have indicated the beneficial effects of enclosing fruit in plastic film of specific gas permeability. Because of the increasing demand for fresh-cut (minimally processed) salads, research has been directed at studying the behaviour of fresh-cut produce (e.g. pepper rings, cut tomato salads) during storage and marketing. Because of the increased perishability of fresh-cut produce and the danger of microbial activity, stringent packaging and storage techniques must be applied. This review is concluded with a brief consideration of future research perspectives.
Eggplant genotypes of white, green and violet are very popular in the specific regions of sub-tropics and tropics. These possess enormous health benefits as having high antioxidant activity. Due to limited shelf life i.e. 3 days at ambient storage, wholesalers and retailers apply many unhygienic practices. They use petroleum based oil to make the fruit surface shiny and attractive. In the present study, Eggplant genotypes, viz. violet, green and white, were assessed after carnauba wax (CW) emulsion containing additives such as 2.5% polyethylene glycol (PEG) and 0.5% sodium alginate (SA) as T1, 0.5% SA as T2, 2.5% PEG as T3 and non-coated eggplant fruits as control fruits (T4) for shelf life extension and retention of nutritional quality attributes at ambient condition (20 ± 2 °C and RH 52–54%) for 7 days. The additives mixed CW coatings were effective in extending the shelf life and retaining the nutritional quality attributes than control genotypes. Sodium alginate (SA) mixed CW coating resulted in maximum shelf life extension of white eggplant genotypes by 7 days as compared to 3–4 days in control eggplant genotypes at ambient storage. However, 6.9%, 1.83% and 6.04% decrease in physiological loss in weight was obtained in 0.5% SA based CW coating after 5 days of ambient storage of violet, green and white eggplant genotypes, respectively in comparison to fully control eggplant genotype. The firmness level of eggplant genotypes in 0.5% SA based CW coating was more (85.1%, 50% and 45%) after 7 days of ambient storage of violet, green and white genotypes, respectively in comparison to fully control eggplant genotype. Similarly, total phenol content was also increased (26.1%, 37.5% and 180.9%) in 0.5% SA based CW coated eggplant genotypes of violet, green and white, respectively after 7 days of ambient storage in comparison to fully control eggplant genotype. Initially there had been increase in antioxidant activity in white genotype up to 5 days of storage which thereafter decreased on 7 days of storage in all the treatments. However, violet and green genotypes had not followed any trend during storage.
Physiological disorders in harvested eggplant (Solanum melongena L.) fruit result in quality deterioration, short postharvest life and significant economic losses. In this study, the effects of methyl jasmonate (MeJA) on senescence in eggplant fruit were investigated. The results indicated that, compared to control, MeJA at 5 μM depressed ethylene production and effectively delayed fruit senescence. MeJA treatment was beneficial for maintaining fruit quality during storage, inhibiting increase of the calyx browning and weight loss, and retarding decline of sensorial quality, firmness and the anthocyanin content in peel. Moreover, MeJA effectively reduced the total phenolics content and the activity of the polyphenol oxidase (PPO) in calyx and pulp. MeJA also inhibited relative gene expression of PPO in pulp. The activities and gene expression of peroxidase and catalase were significantly induced by MeJA treatment. These findings indicate that the delayed senescence in eggplant fruit by MeJA is related with the decrease of enzymes associated with phenolics metabolism and antioxidant system. Our results suggest that MeJA has potential effect on maintaining the quality and extending postharvest life of eggplant fruit.
This research was designed to develop and test an automatic image analysis method (algorithm) to classify CT images obtained from 1233 carrot (Daucus carota L.) sections (samples), collected during the 2013 and 2014 harvesting seasons. Classification accuracy was evaluated by comparing the classes obtained using eighteen CT images per carrot section to their undesirable fibrous tissue class, based on the industry-simulated invasive quality assessment (% of fiber). Class-0 represents fibrous-free samples, and class-1 denotes samples containing fibrous tissue.
After CT image preprocessing, cropping, and segmentation, 3762 grayscale intensity and textural features were extracted from the eighteen CT images per sample. A 4-fold cross-validation linear discriminant classifier with a performance accuracy of 87.9% was developed using 95 relevant features, which were selected using a sequential forward selection algorithm with the Fisher discriminant objective function. This objective method is accurate in determining the presence of undesirable fibrous tissue in pre-processed carrots.
This research was devised to evaluate Computed Tomography (CT) for asparagus fibrousness detection and more specifically develop and test an automatic image analysis method (algorithm) to classify CT images obtained from 859 asparagus (Asparagus officinalis L.) segment (samples), collected during two harvesting seasons (2014 and 2015). Classification accuracy was calculated by comparing the classes obtained using a combination of imaging, image processing, feature extraction, and classification schemes per asparagus segment against an industry-simulated invasive quality assessment.
Grayscale intensity and textural features, 3762 total, were extracted from minimum and maximum resultant images from three CT planer views. A 4-fold cross-validation linear discriminant classifier with a performance accuracy of 91.2% was developed using 75 relevant features, which were selected using a sequential forward selection algorithm with the Fisher discriminant objective function. This objective method is accurate in determining the presence of tough-fibrous tissue in asparagus, which demonstrates a potential for such technology to objectively forecast asparagus quality and thus supports the asparagus industry through optimizing consumer acceptability and product utilization.
Gloss measurements are used to evaluate the quality and appearance of a product, especially in cases where esthetic appearance is of importance. Most commercial glossmeters are designed for measuring products of flat surface and therefore are not suitable for food products because of their uneven, curved surface. A new generation of commercial glossmeters is recently available for confined areas, curved surfaces, and surfaces that are not uniform. This article provides a brief review of gloss measurement principles and methods for fresh fruits and vegetables. It reports on the gloss measurement of apples and other fresh products using a commercial glossmeter and a specially designed spectrometer-based gloss measurement prototype integrated with imaging and automatic sample positioning capabilities. Results showed that the prototype had a nonlinear relationship with standard gloss measurements. With the new setup, the gloss of apples was measured with the repeatability for 90% of the measurements being better than 16%, calculated as the ratio of the difference between maximum and minimum gloss values to the mean value in percent. Further research is needed to simplify the imaging/mechanical configuration and improve the coordinate calculation algorithm to achieve more accurate, repeatable gloss measurements.
Bulk density, true density, angle of repose, coefficient of friction on metal surfaces, specific heat, thermal diffusivity and conductivity of gorgon nut were determined using standard techniques for different sizes of nuts at moisture contents and temperatures ranging from 15 to 60% (dry basis) and 25 to 55C, respectively. the physical properties varied quadratically with moisture content. Specific heat increased with moisture and temperature but decreased with the size of the nut; whereas, the thermal diffusivity showed a reverse trend. Thermal conductivity increased with moisture content but did not follow any trend with temperature within the range of the study. the physical and thermal properties data at various moisture contents and temperatures were used to develop equations for different sizes of gorgon nuts.
Gorgon nuts are processed for their kernels in expanded form and this is known as makhana in India. Operations involved in the traditional method of processing make it laborious, time consuming and costly. This paper reports an investigation into the effect of five combinations of operations on recovery of makhana, viz., (1) roasting and popping; (2) drying, roasting and popping; (3) drying, tempering, roasting and popping; (4) first roasting, tempering, second roasting and popping; and (5) drying, first roasting, tempering, second roasting and popping. The design of the experiments was based on response surface methodology and they were conducted using thin-layer drying and a manual roasting method.The best combination of operations,based on the recovery of grade 1 makhana, was found to be number 5 above, that is, drying, first roasting, tempering, second roasting and popping. The data was analysed to find the optimum processing conditions, to give 97% grade 1 makhana. These were found to be a combination of first roasting of dried nut (moisture content 33% d.b.) at 335°C for 3·9 min, tempering for 23 h and second roasting at 335°C for 2·8 min. These conditions reduced the processing time to less than one-half as compared with the traditional method.
A high-density spectrophotometer with fiber optic attachment was used to study the light transmittance through different regions of green tomatoes. The average of transmittance readings taken at four locations around the fruit was found to correlate with the maturity of the fruit. The correlations between optical criteria and the maturity of four varieties of tomatoes are given.
Consumers are now more conscious about quality and source of their foods. Attempts made to determine the quality of food materials are numerous, but most of them are destructive in nature. In recent years, nondestructive methods of quality evaluation have gained momentum and a considerable attempts have been made to develop them. This paper reviews application of these non-destructive methods: magnetic resonance imaging, x-ray computer tomography, near infrared spectroscopy and a few other important techniques for determination of different quality attributes with emphasis on fruits and vegetables, and discusses their pros and cons for practical exploitation.
Surface gloss, stiffness and density were considered to be the prime contributors to
the freshness of eggplant fruit. The freshness index was defined as the ratio of product of
relative spectral reflectance (surface gloss) and stiffness ratios to the density ratio. Surface
gloss was measured in terms of relative spectral reflectance using a computerized spectral
radiometer system while stiffness was determined as an initial slope of force deformation curve
obtained on a uniaxial compression testing machine. Weight and volume for computing density
of eggplant were determined by standard methods. These parameters were changed to
consumers’ acceptable limit by storing the eggplants for different periods at 25±2°C temperature
and 90±5 % relative humidity. Experiments were replicated 5-8 times and the average values
were used to compute dimensionless ratios (values at any time divided by initial value) that
were later used to determine the freshness index. Various forms of equations were tested for
best fitting to the data.
Freshness index of eggplant fruit decreased exponentially with storage period while it
varied in form of power equation of weight and density ratios. It attained the lowest value (5.6
%) at acceptable limit of weight ratio of about 0.87. The best relationships between freshness
index with weight and density ratios was found to be in form of power equation (correlation
coefficient 0.99) while decrease in price of eggplant was seen linear (correlation 0.98) with
computed freshness index by these equations. This showed that the developed freshness index
might estimate the price of eggplants using these equations satisfactorily.
Fresh mushrooms (Agaricus campestris) packed in polystyrene trays covered with polyvinylchloride (PVC) film were gamma irradiated with a dose of 3 kGy to delay senescence and extend shelf-life. Control and irradiated samples were stored at 10 ± 2°C and 94 ± 6% relative humidity (RH) for 17d. Some physicochemical analyses: weight loss; acidity; and texture (using a Universal Testing Machine) were performed to verify possible changes due to the irradiation treatment. Weight loss increased with storage time, without significant differences between control and irradiated samples. On day 14, irradiated mushrooms showed values which were considered still as acceptable (140 g/kg). A slight initial increase in acidity was observed in irradiated samples, which diminished with storage time. The force required to compress the mushroom cap between its edges decreased more steadily in control than in irradiated samples with storage time, probably due to the cap opening inhibition observed in irradiated mushrooms. Relaxation parameter and springiness showed no differences either between samples or along storage time. Shear force increased in every sample with storage, without significant differences between control and irradiated mushrooms.
A glossmeter, suitable for measuring the gloss on curved surfaces has been constructed. The gloss of ripe banana, green bell pepper, orange, tomato, eggplant and onion were checked with an incident laser light at 45° and 60°. Reflected light was collected by photosensors and the image was analysed using appropriate software. L, a, b, °Bx, pH and gloss of fruits and vegetables were checked once they reached the stage of ready to eat. Eggplant and green bell pepper presented the highest gloss properties under investigating conditions, while banana and unwaxed orange exhibited the lowest sheen. Results of our glossmeter were compared with a commercial glossmeter, designed to check gloss of flat surfaces. In such operations it was necessary to peel and flatten the skin. Gloss of the fruits and vegetables were ranked in a similar way by both apparatus. Linear correlation was found between results of gloss measured at 60° by both apparatuses. It must be emphasized that intact fruits cannot be checked by the commercial glossmeter because of their curved surfaces.
The X-ray computed tomographic (CT) scanner was used to monitor the internal quality changes in peaches during ripening. The physicochemical constituents were monitored and the X-ray absorption expressed in CT number was used as an index. Relationships between the CT number and the physicochemical contents were determined. Results showed that CT number, moisture content and titratable acidity decreased significantly with postharvest ripening time, while pH and soluble solids increased with postharvest ripening time. The X-ray CT number is directly related with density, moisture content and titratable acidity. The soluble solids and pH are inversely related with CT number. X-ray CT imaging can be used as an effective tool in the evaluation of peach internal quality.
A non-destructive mechanical sensor (Cantifruit) was designed to measure the firmness of tomatoes. It consists of a small plunger constrained to penetrate slightly into the fruits, by using an accurate lever mechanism. A highly significant correlation exists between firmness measurements performed with this device and the Stable Micro System (SMS), fitted with the same plunger diameter. Using the Cantifruit, data related to firmness variability and changes are easily obtained. The firmness of a tomato varies about 12% around its circumference. In a single lot of tomatoes picked at the same time, the variability may exceed 25%. If the tomatoes are stored at 4–5 °C and 92–99% relative humidity (RH), their firmness decreases by about 20% over ten days.
The quality of eggplant fruit (Solanum melongena L.) during prolonged storage may be impaired by the susceptibility of the fruits to deterioration and chilling injury at low temperature (< 10 °C). This work shows that eggplants harvested during winter (December–January) were more susceptible to chilling injury than those harvested during spring (March–April). Storing disinfected eggplant fruits inside an unperforated polyethylene (PE) bag enabled them to be stored at 8 °C for more than three weeks without sustaining any chilling injury, whereas disinfected but unbagged control fruits showed severe chilling injury. The cooling rate of the bag-packed fruit was significantly slower than that of the control fruit, and the temperature of the fruit packed in bags was always maintained at 0.5–1.0 °C above the storage temperature.
A unique glossmeter, suitable for measuring gloss of curved surfaces, was used in parallel with a conventional, flat surface glossmeter to measure peel gloss of ripening Dwarf Cavendish bananas. Ripening of the bananas was accompanied by a gradual decrease in gloss, which correlated well with other chemical and physical changes in the banana, including pH, °Brix and starch content of the pulp and peel roughness. Most importantly, the decrease in gloss correlated well with changes in peel colour, the current indicator used to assess banana ripeness, which appropriately, correlated well with chemical and physical changes. It is believed that the decrease in gloss during ripening may be a result of a decrease in epicuticular wax content that was observed. Results suggest that peel gloss measurements have potential as a criteria for determining banana ripeness.
Makhana is the popped expanded kernel of the gorgon nut (Euryale ferox) and is used as a delicious food in India. Presently, it is sorted, graded and used as an ingredient of various ready-to-eat products. High volumetric expansion of makhana increases transport cost and makes it too expensive in distant places. Makhana thus requires further processing to get some value-added products of minimum volume. To develop any kind of product and mechanized system for their production, physical properties are required. Furthermore, since makhana is a seasonal and regional crop its storage conditions are also needed for keeping it appropriately at processing centres. Physical properties of makhana at moisture contents ranging from 5 to 20% (dry basis) and equilibrium moisture content at relative humidities ranging from 11·2 to 88% at temperature 30°C were determined using standard techniques. Physical properties were found to be: test weight (weight of 1000 makhana) 286 to 384 g; bulk density 56·5–84·6 kg/m3; particle density 105–240·6 kg/m3; porosity 29·4–48·9%; angle of repose 33–35·6°; and static coefficient of friction 0·596–0·82 and 0·493–0·684 on galvanized iron and stainless steel, respectively. The equilibrium moisture content of makhana was found to be between 11·5 and 58·9% (dry basis) within the ranges of variables studied.
Nuclear magnetic resonance (NMR) experiments were conducted to find desirable methods for maturity evaluation of avocado fruits. NMR image intensity, the ratio of the oil and water resonance peaks of the one-dimensional NMR spectrum, and both the spin-lattice relaxation time (T1) and spin-spin relaxation time (T2) of water in the fruit were found to correlate with maturity of the fruit. The technique of using a surface-coil NMR probe to obtain the oil/water resonance peak ratio of the signal from a region of an intact fruit produced the best result and has desirable features for high-speed sorting.
Storage temperature is never constant in the distribution chain of fresh foods. Due to the temperature dependence of respiration of fresh produce and O2permeability of a packaging film, fluctuating temperatures result in changes of the internal O2and CO2concentration of Equilibrium Modified Atmosphere (EMA) packaged fresh produce.Therefore, the design of EMA packages was improved by adding mathematical models describing the effect of temperature, O2and CO2levels on produce respiration. The influence of temperature on respiration was described by an Arrhenius type of equation while the influence of O2and CO2on respiration was modelled by a Michaelis–Menten kinetic for 10 types of fresh-cut produce. Compared to unprocessed vegetables a higher temperature dependence of cut/shredded produce was observed. An integrated mathematical model characterized the effect of produce type, produce weight, temperature, O2and CO2dependence of produce respiration, film type, package area and temperature dependence of film permeability for O2in order to predict the internal O2concentration of an EMA package which was designed for equilibrium concentration of 3 mL/100 mL O2at 7°C. The model was validated by packaging 10 types of fresh-cut vegetables and comparing equilibrium O2levels with those predicted at six different temperatures between 2 and 15°C.
Low temperature has been used to extend the shelf life of temperate fruits and vegetables since antiquity, while the negative effect of low temperature (<10oC) on the shelf life of tropical plants and commodities has been known since at least the eighteenth century. Low temperature storage has the additional benefit of protecting non-appearance quality attributes: texture, nutrition, aroma and flavor. Time of day when harvest is performed can influence shelf life. In addition, delays in cooling after harvest can reduce commodity shelf life and quality. In commercial handling, shelf life of commodities may vary greatly from laboratory studies. The distribution chain rarely has the facilities to store each commodity under ideal conditions and requires handlers to make comprises as to the choice of temperature and relative humidity (RH). These choices can lead to physiological stress and loss of shelf life and quality. This limitation, especially late in the handling chain during retailing, requires all participants in the distribution chain to increase their understanding of the need to improve management of handling, temperature and RH, to limit losses in quality. Simulated storage studies should be conducted under conditions that approximate the average to better levels of commercial practices.
Peel gloss as a potential indicator of banana ripeness. Lebensmittel-Wissenschaft und-Technologie
- G Nussinovitch
G; Nussinovitch A (1996). Peel gloss as a potential indicator of banana ripeness. Lebensmittel-Wissenschaft und-Technologie, 29, 289–294, doi: 10.1006/fstl.1996.0043 S. N. JHA ET AL.
Extending the shelf life of melongene (Solanum melongena L.) using polymeric films
- Mohammed
M; Sealy L (1986). Extending the shelf life of melongene (Solanum melongena L.) using polymeric films. Tropical Agriculture, 63, 36–40
Maintenance of eggplant fruits quality inside lining during storage Gloss evaluation of materials
- I Rosenberger
- Apelbaum
Rosenberger I; Apelbaum A (1993). Maintenance of eggplant fruits quality inside lining during storage. Hssadeh, 73, 1120–1123, (in Hebrew with an English summary) Hunter R S (1952). Gloss evaluation of materials. ASTM Bulletin, 186, 48–55
Gloss evaluation of materials
- Hunter
Non-destructive techniques for quality evaluation of intact fruits and vegetables—a review
- Jha
Designing equilibrium modified atmosphere packages for fresh-cut vegetables subjected to changes in temperature
- J Leisbeth
- D Frank
- D Tom
Maintenance of eggplant fruits quality inside lining during storage
- Fallik