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Browning Evaluation of Ready-to-Eat Apples as Affected by Modified Atmosphere Packaging
Abstract
The color and polyphenol oxidase (PPO) activity of fresh-cut Golden delicious apples were evaluated throughout cold storage under modified atmospheres. The shelf life of cut apples was extended to several weeks, especially when an initial atmosphere of 90.5% N(2) + 7% CO(2) + 2.5% O(2) and plastic pouches of 30 cm(3)/cm(2) x bar x 24 h were used. Under these conditions, a maximum 62% PPO activity depletion was observed. In all cases, the faster the initial PPO activity decays, the less the color changes. A fractional conversion first-order model was proposed for predicting color changes in minimally processed apples. Browning was better described through lightness (L) (k(L) = 0.017 - 0.07 day(-1)) and color difference (Delta E*) values (k(Delta E) = 0.015 - 0.073 day(-1)), which fitted the model with enough accuracy.
Supplementary resource (1)
... Apple juice browning was fitted to a fractional conversion model according to Eq. (2), as previously proposed by Soliva-Fortuny et al. (2001) and López-Nicolás et al. (2007a), using a nonlinear regression procedure of Statgraphics Plus (version 5.1) software. ...
... Such enhanced phenolic extractability after mild HPP treatments has been widely reported in apple juice and other beverages (Queiroz et al. 2010). (lines) with a zero-order kinetic in the final lineal portion (representing k 0 in min −1 (R 2 )) of the data Colour changes of the apple juice were well fitted using the model proposed by Soliva-Fortuny et al. (2001). Particularly, Soliva-Fortuny et al. (2001) modelled the influence of enzymatic browning on the colour parameters of fresh-cut apples under several conditions. ...
... (lines) with a zero-order kinetic in the final lineal portion (representing k 0 in min −1 (R 2 )) of the data Colour changes of the apple juice were well fitted using the model proposed by Soliva-Fortuny et al. (2001). Particularly, Soliva-Fortuny et al. (2001) modelled the influence of enzymatic browning on the colour parameters of fresh-cut apples under several conditions. In that sense, experimental colour data were fitted with this first-order model showing root mean square deviations (RMSE) that ranged from 0.16 to 0.34 (Fig. 1). ...
Browning control in apple juice has been one of the highest challenges within food technology. High pressure processing (HPP) ensures quality and safety in apple juice during its shelf life, but enzymatic browning may be increased. Hence, the effects of addition of α- (10/30/40 mM) and β-cyclodextrins (CDs) (5/10/15 mM) during apple juicing and HPP treatment (0/300/400/500 MPa; 5 min, 22 °C) were studied on the browning index (BI) and phenolic compounds degradation at 22 °C. In general, apple juice browning was well fitted with a first-order kinetic. Contrary, phenolic degradation was better fitted with a zero-order kinetic. The highest HPP treatment induced the highest apple juice browning, while it was minimum in untreated samples. Nevertheless, 30 mM α-CD addition to the apple juice may reduce the related HPP browning. Chlorogenic acid and (−)epicatechin showed the highest degradation rates related to browning, while phloridzin did not show high changes after juicing. A β-CD concentration of 15 mM was needed to prevent browning of the 500 MPa-treated juice. Consequently, the use of α- and β-CDs may control enzymatic browning caused by HPP through the quick encapsulation of the phenolic compounds.
... Los cambios en el estilo de vida de las personas, junto con la concientización entre los consumidores sobre la importancia de una alimentación saludable, han generado una demanda creciente de frutas y hortalizas mínimamente procesados, con atributos de calidad (tales como apariencia, textura y flavor), similares a los de los productos frescos (Soliva--Fortuny et al., 2001). Para las personas activas, las manzanas frescas cortadas constituyen una forma práctica y con bajo aporte de calorías, de consumir frutas "al paso" (Abbott et al., 2004). ...
... El mínimo procesamiento se ha definido como una combinación de procedimientos, como lavado, clasificación, recorte, pelado o cortado, que permiten obtener un producto con características similares a las de la fruta u hortaliza original (Soliva--Fortuny et al., 2001). ...
... Debido a que la integridad celular de las frutas es alterada durante el procesamiento, los productos listos para consumir son más perecederos que los frutos originales (Soliva--Fortuny et al., 2001). Por lo tanto, el desarrollo de productos frescos cortados requiere una adecuada selección de la variedad así como la utilización de métodos de preparación y condiciones de almacenamiento apropiados (Abbott et al., 2004). ...
The application of chemical treatments based on citric acid, ascorbic acid and calcium chloride to fresh cut Granny Smith apples during refrigerated storage was evaluated. Three treatments were applied by dipping the washed, disinfected, peeled and cut into eighths apples: water (T1), aqueous solution of 0.5% citric acid + 0.5% ascorbic acid + 0.25% calcium chloride (T2), and aqueous solution of 1.0% citric acid + 1.0% ascorbic acid + 0.5% calcium chloride (T3). pH, soluble solids, firmness, color (L*, a*, b* C*ab, hab), polyphenol content and antioxidant capacity were determined on raw material (MP), and treated samples after 0 and 7 days of storage at 1.5 °C. The overall appearance, presence of off-odors, browning development, presence of off-flavors and texture were sensory evaluated. The minimal processing reduced firmness, soluble solids content, and luminosity (L*) of the pulp of MP. No significant differences (p> 0.05) were found among samples treated with T1, T2 and T3 on the processing day. T2 and T3 reduced the initial pH of the samples. Apples T3 showed lower values of a*, b* and C*ab and higher values of hab over both the processing day and after 7 days. T2 and T3 maintained the initial content of polyphenols and antioxidant capacity of MP. T3 treatment had the lowest levels of off-odors, browning and off-flavors development, and the highest values in texture and overall appearance, both at the processing day and after 7 days. It can be concluded that the application of T3 treatment was effective in reducing the deterioration of fresh cut Granny Smith apples during refrigerated storage.
... The influence of chemical treatments on the colour of fresh-cut apples was evaluated by monitoring the changes in colour values (L*, a*, b*) at the surface of apple pieces stored at 8 °C for 14 days. The CIELab parameters are frequently used in monitoring the browning of cut apple surfaces, a decrease in L* value and an increase in a* value being indicative of browning (Soliva-Fortuny et al., 2001;Rojas-Graü et al., 2008). ...
... The L* values of fresh-cut apples decreased during storage for all treatments (Figure 1). This trend was also found in previous studies (Soliva-Fortuny et al., 2001;Raybaudi-Massilia et al., 2007) and it was attributed to enzymatic browning caused by tissue damage with consequent enhanced contact between enzymes and substrates (Rojas-Graü et al., 2008). A lower decrease in L* values of treated samples compared to non-treated samples during storage showed that the chemical treatment preserved the natural colour of the fresh-cut apples. ...
The objective of this study was to investigate the effects of dipping in solutions of citric (2%), benzoic (0.2%), sorbic (0.2%) and ascorbic (0.5%) acids and in acidic electrolyzed water on the quality attributes and surface microbiota of fresh-cut apples, cvs ‘Florina’ and ‘Ionathan’, packaged in disposable plastic containers under normal atmospheric conditions during 14 days storage at 8 °C. The colour, firmness, total phenolic content, antioxidant activity and surface microbial load were determined weekly throughout storage. The colour results indicated that acidic electrolyzed water reduced browning while the ascorbic and citric acids were less effective in controlling the enzymatic browning of fresh-cut apples. After 14 days of refrigerated storage, the samples treated with 2% citric acid and acidic electrolyzed water maintained significantly higher firmness, total phenolic content and antioxidant activity than the other treated and control samples. The microbiological analysis revealed that organic acids successfully suppressed bacterial growth throughout the storage period as compared to the control samples. The sorbic and benzoic acids at 0.2% were also effective on yeasts but these dip treatments determined a higher darkening, yellowing and loss of firmness and of antioxidant activity during storage.
... Mathematical models can integrate the abovementioned aspects of food quality and can be used to predict the optimal shelf-life for MPFC apple products using predictive food microbiology models, which is an efficient method to determine products' shelf-life (Kreyenschmidt & Ibald, 2012). Current literature suggested that there is a large number of data focused on the shelf-life of fresh-cut apples under laboratory settings (Putnik & Bursa c Kova cev c, 2017;Putnik, Bursa c Kova cevi c, Herceg, & Levaj, 2016a;Soliva-Fortuny, Grigelmo-Miguel, Odriozola-Serrano, Gorinstein, & Martin-Belloso, 2001). However, predicting the shelf-life of MPFC apples from food physicochemical parameters and microbial spoilage under industrial setting had not been studied yet. ...
... Production of the packaged fresh-cut apples in the modified atmosphere 20 Kgs of each apple cultivar were washed with water and processed under industrial settings (Fragaria d.o.o., Zagreb, Croatia). Apple pieces (1 cm thick) were then subjected to one of the following treatments for 3 min: (i) no treatment (control); (ii) mixture of ascorbic (10 g/dm 3 ) and citric acid (2 g/dm 3 ) with/ without exposure to ultrasound; and (iii) Ca-ascorbate (10 g/dm 3 ) with/without exposure to ultrasound (Aguayo et al., 2010;Pizzocaro, Torreggiani, & Gilardi, 1993;Soliva-Fortuny et al., 2001;Son et al., 2001). The apple pieces were dipped in 30 L of the antibrowning solution (T ¼ 4e7 C) in plastic basins and the ultrasound treatment was carried out using an ultrasonic bath (Bandelin Sonorex, Germany) at frequency of 40 kHz for 3 min. ...
The objective of the present study was to determine the shelf-life of minimally-processed fresh-cut apples treated with anti-browning agents under modified atmosphere packaging. Shelf-life is calculated by application of mathematical models with product quality attributes such as: pH; soluble solids content (SSC); CIELab color parameters; sensory evaluation; and microbial spoilage (Salmonella spp., Staphylococcus aureus, Sulfite-Reducing Clostridium, Enterobacteriacae, Escherichia coli, Aerobic mesophilic bacteria (AMB), yeast, mold, Listeria monocytogenes). Golden Delicious and Cripps Pink apple cultivars were individually treated with one of several anti-browning treatments and packaged in a modified atmosphere (N2=90.5%; CO2=2.5%; O2=7%), and stored at 4 °C. The treatments were; 1) non-treated (control); 2) dipping in a mixture of ascorbic and citric acids for 3 min with and without ultrasound (40 kHz, 3 min) treatment; and 3) Ca-ascorbate with/without ultrasound (40 kHz, 3 min) treatment. Results revealed that Cripps Pink was the most suitable variety for minimally-processed fresh-cut product. All the investigated treatments were equally effective in improving the quality of the product compared to the control. Shelf-life predictive models were developed based on the following quality attributes: apple cultivar, anti-browning treatment, color parameters, sensory evaluation, pH, and SSC. Maximum growth rates for Enterobacteriacae and Aerobic mesophilic bacteria were 0.25±0.02 log CFU/g/day and 0.46±0.02 log CFU/g/day, respectively. In order to optimize fresh-cut production, these models can be useful tool for predicting the longest shelf-life time with monitoring microbial activity during production. All models are freely available on-line (“Anti-browning Apple Calculator – C.A.P.P.A.B.L.E.©”; apple.pbf.hr or 31.147.204.87).
... Fresh-cut processing has gained an increase in popularity as it provides convenient and healthful fruits and vegetables while retaining freshness and nutrients of the non-processed products (Ramos-Villarroel et al. 2011). Fresh-cut fruit processing involves preparation processes such as peeling, slicing and/or cutting which increases the rate of respiration and biochemical reactions in fruit and resulted in negative effects on the quality and safety of the product (Soliva-Fortuny et al. 2001). Therefore, an appropriate technique for prolonging shelf life without detrimental effects on quality of fresh-cut products would be beneficial for consumer and producer. ...
... On the other hand, PL treatment at 12 J/cm 2 reduced growth of Escherichia coli and Listeria innocua in fresh-cut avocado and watermelon but resulted in browning and softening (Ramos-Villarroel et al. 2011. As mentioned earlier, quality and safety of fresh-cut fruit can be negatively affected during fresh-cut processing (Soliva-Fortuny et al. 2001). Moreover, different serovars of Salmonella and Listeria were linked to foodborne outbreaks due to consumption of cantaloupe, occurred from 2008 to 2012 (CDC 2015). ...
The aim of this study was to investigate the effect of cut type and pulsed light (PL) fluence on microbiological stability and quality of fresh-cut cantaloupes. Fresh-cut cantaloupes with various cut types (cuboid, triangular prism and sphere) were treated with PL technology at 6 J/cm2. Samples were exposed to PL treatment at fluences of 2.7, 7.8, 11.7 and 15.6 J/cm2 followed by storage at 4 ± 1 °C for 28 days. Microbiological quality, headspace composition, firmness, colour, pH, titratable acidity, total soluble solids, total phenolic content and ascorbic acid content of fresh-cut cantaloupes were determined. Spherical shape was found to be the most suitable shape for PL treatment of fresh-cut cantaloupes due to its significantly lowest (p ≤ 0.05) microbial counts before and after the PL treatment. No significant (p > 0.05) effect was observed for firmness, colour, total soluble solids and total phenolic content of fresh-cut cantaloupes throughout the storage study. Pulsed light treatment using 7.8 J/cm2 was the best for extending shelf life of fresh-cut cantaloupes with extension of 8 days longer at 4 ± 1 °C compared to the control while maintaining the ascorbic acid content. In conclusion, PL treatment is a potential technique for extending the shelf life of fresh-cut cantaloupes by inactivating microorganisms without compromising the nutritional value.
... Apple cubes in MAP were efficiently preserved from browning and showed the lowest colour losses when initially displacing O 2 by injecting 100 kPa N 2 and a low O 2 permeability film was used. This atmosphere was the main factor affecting lightness, and L* changes occurred four times more slowly than when O 2 was about 2 kPa or when medium O 2 permeability films were used (Soliva-Fortuny et al., 2001). ...
... A first order model fitted with enough accuracy was proposed for predicting colour changes. Browning was better described through decrease in L* and increase in total colour difference with respect to the initial values (Soliva-Fortuny et al., 2001). ...
... Among the treatments used, the most recommended is ascorbic acid (AA) with its derivatives. Its effectiveness has been confirmed by numerous studies, on different fresh-cut fruits and at different concentrations Agar, et al. [19], Chiabrando & Giacalone [30], Dorantes-Alvarez, et al. [31], Soliva-Fortuny, et al. [16] showed that AA at 1% + 0.5% of CaCl2 reduced tissue browning from 31 to 62% in apples stored for 3 months. ...
The ready-to-eat fruit and vegetable market has rapidly grown in recent years due to the health benefits associated with these foods and to the increased health consciousness of consumers with busy lifestyles and increased purchase power. Nevertheless, ready-to-use commodities are more perishable than the original materials. The main factors affecting the loss of consumer acceptability are discoloration, enzymatic browning, dryness and texture loss. These parameters determine the visual appearance of the fruits. For this reason, the fruit processing industry requires the development of techniques capable of keeping safe shelf-life, preserving the original visual and organoleptic fresh-like characteristics of fresh-cut products. Another problem associated with the ready-to-eat products, is the microbiological growth. The metabolism of molds and yeasts is responsible for the qualitative decay of minimally processed fruits, so the products decontamination became essential. Natural antimicrobials, ozone, chlorine dioxide, UV and cold gas plasma are some of the different treatments proposed. In combination with these treatments, some actions are carried out to limit the oxidative browning and the firmness loss. Ascorbic acid is the compound most extensively used to avoid the oxidative browning of the fruits, however nowadays there are many alternatives, like chemical or physical treatments. The edible coatings could be effective systems to preserve fresh cut fruits quality, their actions are due to the barrier forming against external agents; in addiction, they could carry functional ingredients (antioxidant, antimicrobial, calcium salts). In conclusion, the treatments aimed to preserve minimally processed fruits quality could be chemical or physical, innovative or more established, cheap or expensive or they could require complex equipment. This review describes the most significant contributions regarding preservation of fresh-cut fruits in order to evaluate their effectiveness in preserving quality traits.
... Within possible methods to be applied to protect product and reduce losses, there are dedicated packaging systems which allow to prolong the shelf life [17]. Such systems include controlled and modified atmosphere packaging (MAP) [18], which refer to the technique of sealing actively respiring produce in polymeric film packages to modify the O2 and CO2 levels within the package atmosphere [19]. MAP is especially valuable for fruit, as they allow reduction of fruit loss, due to reduced respiration, ethylene production, and sensitivity to ethylene, as well as retarded softening and compositional changes, alleviation of certain physiological disorders, and reduced decay [20]. ...
1-Methylcyclopropene (1-MCP), being applied in postharvest treatment of apples as an inhibitor of ethylene perception, contributes to improved quality of apples during 6 weeks of simulated long-distance transportation, but it was not studied if this period may be prolonged. The aim of the present study was to assess the possibility to apply 1-MCP treatment to maintain the quality of Idared apples for long-distance transportation prolonged for 8 weeks. The 1-MCP treatment was applied either alone, or combined with modified atmosphere packaging (MAP) in selected gas permeability bags and was compared with control group. Postharvest, the storage in Ultra Low Oxygen (ULO) chamber was applied (3 periods: 0, 10, or 20 weeks), followed by simulated long distance transportation (storage duration of 8 weeks) and simulated distribution (4 periods: 0, 5, 10, or 15 days). Each studied group (36 groups: 3 postharvest treatments × 3 storage periods × 4 distribution periods) constituted 4 batches with 10 random apples each. After simulated distribution period, each sample was analyzed to assess the differences of firmness, total soluble solids (TSS) and titratable acidity (TA). The applied treatment influenced observed values of firmness, TSS and TA within each applied storage duration and duration of distribution (p < 0.05). For the majority of the studied durations of storage and distribution, the highest values of firmness, TSS and TA were observed for the samples from the group of 1-MCP applied combined with MAP, while only for some of them, the highest values of firmness and TA, but not TSS, were observed for the samples from the group of 1-MCP applied alone. It may be concluded that applying 1-MCP in the case of Idared apples for long-distance transportation allows prolonging it to 8 weeks without decreasing quality of fruits. Applying 1-MCP combined with MAP allows obtaining even better results than 1-MCP alone, after 8 weeks of transportation. It may be recommended to apply 1-MCP combined with MAP in order to slow the ripening process and to maintain the quality of apples during a long-distance transportation. Citation: Tomala, K.; Guzek, D.; Głąbska, D.; Małachowska, M.; Krupa, T.; Gutkowska, K. The Influence of 1-Methylcyclopropene on the Quality Parameters of Idared Apples after 8 Weeks of Storage Simulating Long-Distance Transportation. Agronomy 2021, 11, 528.
... The ascorbic acid concentration was selected according to Soliva-Fortuny et al. (2001). ...
Fresh-cut apple browning has been conventionally tried to control with the help of ascorbic acid dips, although such antioxidant effect is limited. Lycopene, absent in apple flesh, is the carotenoid in nature with the highest antioxidant capacity, in special for its cis − isomers. Tomato skin is a low cost by-product with very high ly-copene content (7.23 g kg −1) and high potential to be incorporated as an antioxidant agent in antibrowning dipping treatments. High lycopene extraction from tomato skin was achieved with a thermal treatment (75 °C, 1 h) favouring trans − to − cis lycopene isomerization with TiO 2 nanoparticles. Lycopene extracts were highly encapsulated (encapsulation efficiency: 92.2%) with the complex coacervation method and the obtained mi-crospheres were then incorporated in dipping treatments (0.5 (L0.5), 1 (L1) or 2 g L-1 (L2)) during fresh-cut apples processing, compared with an ascorbic acid dipping (AA; 10 g L-1). Quality changes (colour, microbial, physicochemical and bioactive compounds) were studied up to 9 d at 5 °C. The L2 dipping controlled better the browning during storage, showing the lowest browning index among treatments (BI = 43.8) after 9 d. Furthermore, L2 dipping did not affect the physicochemical quality of samples, while maintaining a good microbial quality. Incorporation of lycopene microspheres also improved the bioactive quality of samples, still showing total cis − lycopene isomer content of ≈ 20 mg kg −1 after 9 d. Furthermore, chlorogenic acid, the predominant phenolic acid, content was enhanced by 56% in L2 samples after 6-9 d. In conclusion, a dipping treatment of fresh-cut apples including 2 g L-1 lycopene microspheres reduced browning, while quality was maintained and some bioactive compounds even enhanced after 9 d at 5 °C.
... PPO activity was determined using a spectrophotometric method based on an initial rate of increase in absorbance at 420 nm (Soliva-Fortuny et al., 2001). The activity was assayed in 3mL of reaction mixture consisting of 1mL of substrate (0.02 M pyrogallol + distilled water), 100 µl of the enzyme and 1.9 mL of phosphate buffer (pH 6.5) in a 1cm light path quartz cuvette. ...
Wheat (Triticum aestivum L. em Thell.) is an important cereal crop in Egypt and all over the world. Powdery mildew caused by Blumeria graminis f.s tritici is one of the most devastating diseases of wheat worldwide. The present work designed to control powdery mildew disease of wheat plants through the nano technology, bioagents and some chemical inducers. All tested isolates of antagonistic fungi significantly reduced powdery mildew disease of wheat plants. Nano silicon or titanium, bioagents and chemical inducers were evaluated for their efficiency to control powdery mildew and effect on yield of wheat plants cv. Misr-1 in North Sinai governorate during 2015/2016 and in Beheira governorate during 2015/2016 and 2016/2017 growing seasons. The most effective treatments are SNPs and TNPs obtained by P. putida (PpFT1) and B. subtilis (BsBN3) which reduced the disease severity. Followed by SNPs and TNPs obtained by T. harzianum (ThFT1), T. hamatum (TmSA2), T. viride (TvGK2)and P. fluorescens (PfBN1) in compared with methyl jasmonate and arginine . All tested treatments significantly increase the growth parameters i.e. fresh weight of plant (g) and Spike weight (g). The highest increase was obtained with SNPs and TNPs obtained by all tested bioagents. The highest increase was obtained with SNPs and TNPs obtained by P. putida (PpFT1), B. subtilis (BsBN3) and TNPs obtained by Paenibacillus polymyxa (PbBB2). Treated wheat plants with SNPs obtained by T. harzianum (ThFT1), T. viride (TvGK2) and T. hamatum (TmSA2) resulted in increasing the grain yield. Biochemical studies on the defense mechanisms of wheat plant due to different treatments such as polyphenol oxidase and peroxidase activities, total protein and total phenols were done.The most effective treatments are SNPs and TNPs obtained by P. putida (PpFT1) and B. subtilis (BsBN3) followed by SNPs and TNPs obtained by T. harzianum (ThFT1), T. viride (TvGK2) and P. fluorescens (PfBN1) .All tested treatments significantly increased the polyphenol oxidase and peroxidase activities.
... The slope or decrease in the lightness loss over time was more defined as the storage temperature was higher (Figure 2), with a higher lightness loss at 21 C. This behavior of decrease in lightness has also been expressed in a similar way by using the first-order kinetics, fractional conversion in these cases, in refrigerated storage of feijoa fruits (Castellanos et al., 2016) and fresh-cut apples (Soliva-Fortuny et al., 2001) both in modified atmospheres. The fitted model satisfactorily represented the experimental behavior at the different temperatures evaluated obtaining R 2 values of 0.97-0.99 as shown in Table 4 and according to the closeness between the experimental data measured (symbols in Figure 2) and the data estimated by the model (lines). ...
In this study, 'Hass' avocado samples were stored at different temperatures to determine changes in firmness, color and other physicochemical support properties throughout the storage time and to represent shelf life depending on temperature from the evolution of these quality properties. From the experimental data, a set of models were adjusted to represent the change of each property as a function of time and temperature by using a first-order kinetics to represent the evolution of lightness (L*) and the chromatic coordinate b*, and a logistic equation to represent firmness and a*. The effect of temperature was represented by using Arrhenius equations. From the models of firmness and color, suitable equations were obtained to predict shelf life considering the relationship with the senescence stage (between 20 and 33 days). All the models were adjusted satisfactorily, obtaining regression coefficients higher than 0.95. In order to determine the predictive capacity of the proposed models, a validation experiment was carried out by storing fruits at 12 C until reaching the senescence stage. With the models, it was possible to satisfactorily predict the changes in color and firmness and it was possible to estimate the shelf life time at 12 C (28 AE 3.1 days).
... The development of brown discoloration in a wide variety of fruit and vegetables decreases the consumer tolerability and thus is of considerable economic importance to the primary producer and the food processing trade (Lattanzio et al. 1989;Mathew and Parpia 1971). Handling of fruit and vegetables with injuries in their tissues resulted in the loss of cell compartmentalization (Soliva-Fortuny et al. 2001); consequently, phenolic components get exposed; and their interaction with oxidizing enzymes (Polyphenol oxidase and peroxidase) leads to browning reactions (Degl'Innocenti et al. 2005). These browning reactions in fruits not only reduce the visual quality but also result in loss of nutrients and impairment of flavor leading to decreased consumer acceptability and significant economic losses (Luo and Barbosa-Canovas 1997;Núñez-Delicado et al. 2005). ...
Enzymatic browning in fruits and vegetables occurs by exposure to the air after cutting and slicing and in pulped states, mechanical damage during transportation, and thawing of frozen or cold stored foods. Polyphenol oxidase (PPO) and peroxidase (POD) are the main enzymes responsible for browning. PPO is classified as an oxidoreductase enzyme with four atoms of copper as a prosthetic group. It catalyzes the oxidation of functional OH group attached to the carbon atom of the benzene ring of monohydroxy phenols (phenol, tyrosine, p-cresol) to o-dihydroxy phenols (catechol, dopamine, adrenalin) and dehydrogenation of o-dihydroxy phenols to o-quinones. The oxidation of phenolic compounds to quinones and production of melanin give rise to a dark color in the foods. The POD is thermostable enzyme that belongs to a group of oxidases that use H2O2 as a catalyst for oxidation of phenolic compounds. The POD is related to undesirable changes in flavor, texture, color, and the nutritional quality of foods. The level of PPO and POD varies in fruits and vegetables and their content changes with maturity and senescence depending upon the ratio of bounded and soluble enzymes. Change in color of fruits and vegetables by enzymatic reactions is a major problem during harvesting, transportation, storage, and processing. Color deterioration, off-flavor, and loss of nutritive value in foods are unacceptable to the consumers. The purpose of this chapter is to provide information available in the literature on PPO and POD in different fruits and vegetables, their role in browning/color changes, and available prevention methods.
... In addition, the accuracy cannot be guaranteed because the color of the bruise is slight and shallow. 11 The hyperspectral and multispectral techniques can overcome the shortage of the insufficient information of these methods from its abundant character spatial and spectral data. As a result, the internal composition changes would be related to the change of spectra via analyzing the spectra using chemometrics and machine learning algorithms. ...
BACKGROUND
Bruising time of apple is one of the most important factors for internal quality assessment. The present study aimed to establish a non‐destructive method for the classification of apple bruising time using Visible and Near‐infrared (Vis/NIR) Hyperspectral imaging. In this study, Vis/NIR hyperspectral images were obtained and analyzed at seven bruising periods. Moreover, the regions of (ROIs) were chosen to construct the bruised region classification model, the spectra of the bruised region were collected and resampled based on four different resampling methods. Subsequently, machine learning algorithms were employed and used for dealing with the time classification model of apples. In order to reduce data redundancy and improve the accuracy of classification model, tree based assembling learning model was used to select feature wavelengths and liner discriminant analysis (LDA) was used to improve the discernibility of data.
RESULTS
The results revealed that random forest (RF) model can precisely locate the bruise region, the gradient boosting decision tree (GBDT) model can validly classify the apple bruising time, and its accuracy is 70.59%. The 128 wavebands data was compressed to 13 wavebands and provide a high accuracy of 92.86%.
CONCLUSION
The results prove that the hyperspectral technique can be used for predicting the apples bruising time, which would help to assess the internal quality and safety of apples.
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... The damaged tissues become darkened and brownish within a few hours, may soften or dry later, and may lead to the decay by microbial infections. [2] The identification of bruises is also affected by time, bruise type, bruise severity, fruit variety, and storage conditions. [3] Therefore, nondestructive techniques are needed to detect internal damages of apples quickly and effectively. ...
Hyperspectral imaging technique (400–1000 nm) was used for rapid and nondestructive recognition of bruises of apples. A total of 324 hyperspectral images were collected from 108 Fuji apples and the average spectral reflectance was extracted from the region of interest (ROI) of each image. The classification results of AdaBoost for the data pretreated by various existing methods were compared. Then, the correlation-based feature selection (CFS) algorithm was used to obtain characteristic wavelengths for reducing data redundancy. After pretreating with multiplicative scatter correction (MSC) and CFS, the average accuracy of the selected wavelengths was 97.63%. Then, an image processing algorithm based on the characteristic wavelengths selected before was proposed for the visual discrimination of bruises. This algorithm performed independent component analysis (ICA) transformation of the selected wavelengths, and chose the third component image of the ICA transform, then used adaptive threshold segmentation to obtain the bruise region of apples. The results showed that hyperspectral imaging technology could discriminate apple bruise, and this study can help to develop an online apple bruises detection system.
... Keeping in view these healthy benefits, a consumer is strongly encouraged to consume more fruit and vegetables as a contribution to a healthy, nutritious and balance diet [5]. Consumer demands for fresh, natural, healthy, high nutritious foods with no or minimal chemical preservatives [6,7]. This demand has increased along with the whole crop consumption or food processed minimally [8]. ...
... As this factors had no significant influence on DE Ã a;b and BI, pretreatment with water was excluded from the future experiments. Based from the literature, selected antibrowning solutions were: (a) no treatment/control; (b) ascorbic (1%, w/v) and citric acid (0.2%, w/v); (c) ascorbic acid (1%, w/v) 1 NaCl (0.05%, w/v); (d) NaCl (1%, w/v); (e) citric acid (1%, w/v), and (f) Ca-ascorbate (1%, w/v) (Aguayo et al., 2010;Pizzocaro, Torreggiani, & Gilardi, 1993;Soliva-Fortuny, Grigelmo-Miguel, Odriozola-Serrano, Gorinstein, & Martin-Belloso, 2001;Son et al., 2001). Colorimetric variables were measured at storage times (0, 30, 180, and 1,440 min), and C*, H*, DE Ã a;b , X, and BI were calculated from Equations 1-5 and all samples were subjected to sensory evaluation. ...
This study identified optimal apple cultivars and antibrowning treatments with/without ultrasound for fresh-cut processing with minimal color changes observed during storage. Color changes ( ) were evaluated for various apple cultivars (Idared, Golden Delicious, Gala, Gloster, Cripps Pink, Braeburn, and Fuji) treated with different antibrowning solutions (ascorbic + citric acid; ascorbic acid + NaCl; NaCl, citric acid, and Ca-ascorbate) with/without ultrasound during storage of 24 hr. Also, sensory evaluation was conducted to assess the acceptability of treated apples. The effectiveness of antibrowning treatments with or without ultrasound were determined as negative effect on and browning index over the storage. The best apples were Cripps Pink and Golden Delicious, and solutions were Ca-ascorbate and ascorbic + citric acid. In combination with ultrasound, the best solution was Ca-ascorbate. Exposure to ultrasound confirmed the best suitability of Ca-ascorbate and Cripps Pink for fresh-cut, while implying that longer periods of exposure might be beneficial for prevention of browning in fresh-cut apples. Fresh-cut processing is a significant segment of the worldwide food markets, with fresh-cut apples being one of the most important foods for such production. Fresh-cut apples have short shelf-life that is mainly reduced by browning. Since, profit margin in fresh-cut industry is spread over the short periods of time (largely due to short shelf-life) it is crucial for such industrial processing to identify apples and antibrowning treatments that will extend preservation to longest possible time while assuring consumer acceptance of such products. Simultaneously, it is important to detect advanced nonthermal treatments able to reduce or prevent browning in fresh produce with minimal loss in nutritive value and addition of additives, due to consumers’ tendency to demand such foods.
... Apple pieces were subjected for 180 s to the following antibrowning treatments: (i) no treatment (control); (ii) ascorbic (0.010 kg L 21 ) and citric acid (0.002 kg L 21 ) with/without exposure to the ultrasound; and (iii) Ca-ascorbate (0.01 kg L 21 ) with/without exposure to the ultrasound (Aguayo, Requejo-Jackman, Stanley, & Woolf, 2010;Pizzocaro, Torreggiani, & Gilardi, 1993;Soliva-Fortuny, Grigelmo-Miguel, Odriozola-Serrano, Gorinstein, & Martin-Belloso, 2001;Son, Moon, & Lee, 2001). Cut apple pieces were dipped in 30 L/per antibrowning solution (T 5 4-7 8C) in plastic basins. ...
This study addressed the changes in polyphenolic stability and antioxidant capacity in fresh-cut apples packaged in modified atmosphere (MAP) as a result of: (i) minimal processing parameters (type of cultivar, anti-browning treatments, and the length of storage); (ii) superficial browning, (iii) ultrasound treatment, and (iv) microbial growth during storage at 4 ºC for 14 d. Studied cultivars were Cripps Pink and Golden Delicious. Anti-browning agents were ascorbic with citric acid and sole Ca-ascorbate that were both combined with the ultrasound. Identified phenolic compounds, in all samples were: chlorogenic and p-coumaroylquinic acid, quercetin, epicatechin, and phloridzin. Cripps Pink was richer on flavonoids and had the higher antioxidant capacity than Golden Delicious. Application of any anti-browning treatments did not influence quantities of phenolic compounds but they showed an improved antioxidant capacity in comparison to untreated samples. Phenolic compounds were stable and antioxidant capacity decreased during storage. Microbial growth had no association with the majority of phenolic compounds (except epicatechin), where it was possible that microorganisms oxidized epicatechin to quercetin together with apple respiratory processes.
... Application of antioxidant treatments as dipping after peeling and/or cutting is the most common way to control browning of fresh-cut fruits. Ascorbic acid (l-ascorbic acid) and its various neutral salts and other derivatives have been GRAS (Dorantes-Alvarez et al. 1998;Rocha et al. 1998;Agar et al. 1999;Buta et al. 1999;Gorny et al. 1999;Senesi et al. 1999;Soliva-Fortuny et al. 2001, 2002. The carrageenan-based coatings in combination with ascorbic acid resulted in positive sensory results and reduction of microbial levels on minimally processed apple slices (Lee et al. 2003). ...
The application of edible films and coatings to fresh, minimally processed, and processed fruits and
vegetables extend their commercial shelf life, maintain their microbiological, sensory, and nutritional
quality and have a similar effect on the storage under controlled or modified atmospheres. Some formulations
have been specifically tested on their ability to inhibit PPO activity and delay browning reactions.
In addition, edible films and coatings are able to transport substances that bring some benefits not only
for the food itself but also for the consumer, through the encapsulation of bioactive compounds, developing
new products with nutraceutical, or functional effect. Their use in highly perishable products such
as horticultural ones is based on some particular properties such as the cost, availability, functional
attributes, mechanical properties (flexibility, tension), optical properties (brightness and opacity), barrier
effect against gas flow, structural resistance to water and microorganisms, and sensory acceptability. In
some cases, edible coatings were not successful. The success of edible coatings for fresh products totally
depends on the control of internal gas composition. Edible coating technology seems to be very promising
as long as consumer accept this technology as safe and friendly. Basic information on film-coating
formulation, properties, methods of application to fruit or vegetable surface, and demonstration of effectiveness
is lacking. The interaction of proteins, polysaccharides and lipids in coatings and the interaction
between coatings and plastic packaging need to be explored further for successful commercialization of
this technology. Tremendous research is required in the area of applications of edible coatings and films
on fresh and fresh-cut fruits and vegetables.
... The supernatant was collected and filtered, to obtain the enzymatic extract, required for enzyme activity determination. According to the method of Soliva-Fortuny et al. (2001) and Kołodziejczyk et al. (2010) PPO activity was determined spectrophotometrically, adding 3 mL of 0.05 M catechol and 75 µL of extract into a quartz cuvette. The changes in absorbance at 400 nm were recorded every 1 min up to 3 min. ...
The research project aimed at the investigation of different methods for the storage of fresh-cut fruit. This case study relates to the proposal of an innovative controlled release system to improve the shelf life of ready-to-eat fruit. The methods applied during three research years included the application of active molecules from natural substances, some widely used in commerce and other tested for the first time; first analyzed in vitro and then applied in vivo. The under consideration methods concerned dipping, coating and the layer-by-layer assembly. The analysis carried out on the fruit have monitored pomological traits performances (soluble solids content, titratable acidity, pH, color, flesh firmness), the chemical profile (polyphenoloxidase, carotenoids) and microbial growth.
... However, the respiration and biochemical reactions of fresh-cut fruit still continue even though the fruit has been peeled, sliced and cut. As a result, quality and microbiological safety of the product can be negatively affected due to deterioration of products (Soliva-Fortuny, Grigelmo-Miguel, Odriozola-Serrano, Gorinstein, & Martín-Belloso, 2001). Moreover, foodborne diseases can also occur due to contamination of the product by pathogenic and spoilage microorganisms under inappropriate handling, processing and storage conditions. ...
... when initially displacing O 2 by injecting 100 kPa N 2 and a film with low O 2 permeability was used. This atmosphere was the principal factor affecting lightness, and L* changes happened four times more slowly than when O 2 was about 2 kPa or when medium O 2 permeability films were used (Soliva-Fortuny et al., 2001). Day (1994) has suggested that O 2 levels greater than 21 kPa may influence the postharvest life of intact and fresh processed fruits and vegetables and PPO is probably substrate inhibited by high O 2 levels. ...
This chapter is about the controlled atmosphere (CA) packaging technique. CA storage commonly uses low oxygen (O2) levels and high carbon dioxide (CO2) levels in the storage atmosphere combined with refrigeration. In CA storage, inside a food storage room is the gas composition that continually monitors and adapts to maintain the optimum concentration within completely close tolerances. Because CA storage is capital intensive and expensive to operate, it is more appropriate for those foods that are agreeable to long-term storage such as apples, kiwifruit, and pears. CA packaging is the enclosure of food in a gas impermeable package inside which the gaseous environment with respect to CO2, O2, N2, water vapor, and other trace gases has been changed and is selectively controlled to increase shelf life. Considering the definition, there are no CA packaging systems in commercial use. However, using the combination of O2 and ethylene (C2H4) absorbers, together with CO2 release agents in packaging, at least during the early stages of the storage life of the packaged product, could be classified as CA packaging. There are some functions for the generation and maintaining of CA including O2 removal, excess CO2 removal, and addition of air to replace O2 consumed by respiration, removal of C2H4, and in some cases addition of CO2. Selection of the appropriate functions and devices for generating and maintaining CA depends on what horticultural produce is stored and the storage conditions required for each produce. Research has shown that CA storage has positive, negative, and no effect on certain quality aspects of fruits and vegetables, such as physiological disorders, flavor and off-flavor, acidity, C2H4 production, respiration rate, volatile compounds, phytochemical compounds, color, etc. In this chapter all of these effects are discussed comprehensively.
... Application of antioxidant treatments as dipping after peeling and/or cutting is the most common way to control browning of fresh-cut fruits. Ascorbic acid (l-ascorbic acid) and its various neutral salts and other derivatives have been GRAS (Dorantes-Alvarez et al. 1998;Rocha et al. 1998;Agar et al. 1999;Buta et al. 1999;Gorny et al. 1999;Senesi et al. 1999;Soliva-Fortuny et al. 2001, 2002. The carrageenan-based coatings in combination with ascorbic acid resulted in positive sensory results and reduction of microbial levels on minimally processed apple slices (Lee et al. 2003). ...
Fruits and vegetables are susceptible to spoilage during the postharvest life due to rich nutrient substance, high water content, its own metabolism and microbial infection. The preservation of fruits and vegetables plays a significant role in maintaining their quality, extending the supply period and improving their economic benefits. Edible coatings can form a barrier between the fruit and surroundings, and this semi-permeable barrier has the capacity to modify fruit internal atmospheres, prevent water immigration, reduce mechanical injury to fruit during the transport and storage process as well as lower the risks of microbial contamination. As an effective preservation technology, the properties of edible coatings and films along with its application on fresh fruits and vegetables have been widely studied. In this chapter, in the first part I critically reviewed the effect of application of hydrocolloids, lipids and composite coatings on maintaining the quality of fruits and vegetables, after that I have a focus on the effect of second-generation coating material (bioactive compounds) on human health, especially due to the application of new microencapsulation or nanoencapsulation techniques. Moreover, I also tried to discuss the problem associated with edible coatings and films and their regulatory status and food safety issues.
... The shelf-life of fresh-cut fruits is dramatically reduced by the removal of the protective skin as well as by the deleterious effects of cutting and handling operations. 4,5 Microbial growth and mechanical damage are the main causes of quality decay. ...
Background:
Pulsed light treatments (PL) stand as an alternative for the shelf-life extension of fresh-cut products. The antimicrobial effects of pulsed light are well known; however, influence on quality attributes needs to be assessed. This study was aimed at evaluating the application of PL treatments in combination with pectin-based edible coatings enriched with dietary fiber for the preservation of fresh-cut apples.
Results:
Dipping of fresh-cut apples in ascorbic acid/chloride calcium solution, prior to pectin coating and PL treatments, was effective to minimize browning and softening in apple surfaces. Incorporation of fiber in the pectin coating did not cause any change in microbial loads and sensory acceptability of apple cubes. Pectin-coated PL-treated apple pieces exhibited significantly higher antioxidant activity values than fresh and PL-control samples. At the end of storage, the combination of both treatments resulted into almost a 2 log CFU g(-1) reduction of microbial counts. Sensory attribute scores did not fall below the rejection limit throughout 14 days, although the presence of off-odors limited the acceptability of the pectin-coated samples.
Conclusions:
Results demonstrate that PL treatments applied to pectin-coated fresh-cut apples may be used to maintain quality attributes, thus conferring prebiotic potential and extending the shelf-life of the product.
... Some researchers have proved the eff ectiveness of edible coatings on the control of browning and polyphenol oxidase activity. Application of antioxidant treatments as dipping aft er peeling and/or cutting is the most common way to control browning of fresh-cut fruits [136][137][138][139][140][141][142]. Ascorbic acid (l-ascorbic acid) and its various neutral salts and other derivatives have been GRAS. ...
Edible films and coatings applied to fresh, minimally processed and processed fruits and vegetables are effectivein extending their shelf life, maintaining their microbiological, sensory and nutritional quality. Some formulations have been specifically tested on their ability to inhibit polyphenol oxidase activity and delay browning reactions. In addition, edible films and coatings are able to transport substances that bring some benefits not only for food itself but also for the consumer, through the encapsulation of bioactive compounds, developing new products with nutraceutical or functional effect. Their use in highly perishable products such as horticultural ones, is based on some particular properties such as cost, availability, functional attributes, mechanical properties (flexibility, tension), optical properties (brightness and opacity), the barrier effect against gases flow, structural resistance to water and microorganisms and sensory acceptability. In some cases, edible coatings were not successful. The success of edible coatings for fresh products totally depends on the control of internal gas composition. Basic information on film-coating formulation, properties, methods of application to fruit or vegetable surface and demonstration of effectiveness are lacking. Tremendous research is required in the area of applications of edible coatings and films on fresh and fresh-cut fruits and vegetables.
... The determination of the PPO activity was performed at day 3 and 8 of cold storage at 4°C as described by Soliva-Fortuny et al. (2001). ...
The study was conducted to investigate the behavior of three different edible coatings formulations on the overall postharvest quality of ready to eat Orion nectarines under fresh-cut commercial storage conditions. Three different coatings were used: 1.5% (w/v) sodium alginate coating, 2% (w/v) chitosan coating and a solution of 1.5% (w/v) of chitosan and 1% (w/v) sodium alginate. Fresh-cut nectarines variations in color, flesh firmness, total soluble solids content (TSSC), pH, titratable acidity (TA) and polyphenol oxidase (PPO) activity were measured. Moreover microorganism counts of molds and yeasts were analyzed. The results indicated that treatments with alginate inhibited decrease in firmness, titratable acidity and delayed flesh browning. Furthermore alginate inhibited the PPO activity throughout the storage period considered. Chitosan coating reduced microorganism proliferation of molds and yeasts compared to control treatment. Our study recommends that alginate edible coating treatment may be a desirable method to maintain fresh-cut nectarines quality and to improve nectarines postharvest life.
... Polyphenoloxidase activity was determined according to the method of Soliva-Fortuny et al. [22] and Kołodziejczyk et al. [23]. Enzyme activity was assayed spectrophotometrically by adding 3 mL of 0.05 M catechol (Sigma-Aldrich Chemie, Steinheim, Germany) and 75 µL of extract to a 4.5-mL quartz cuvette of 1 cm path length. ...
Introduction. The use of edible coatings could be a new technological alternative to maintain fruit quality during cold storage. The objective of this work was to determine the effects of different coatings, alone or in conjunction, on the quality of fresh-cut nectarines during storage. Materials and methods. Nectarines (Prunus persica L.) cv. Big Top were studied under three different coatings: 2% acid-soluble chitosan, 1.5% sodium alginate, and a solution with 3% chitosan and 2% sodium alginate. Slices were then sealed in polyethylene plastic bags and stored at 4 °C and 95% RH for 9 days. Titratable acidity, soluble solids content, firmness, weight loss, color, browning potential and polyphenol oxidase activity were determined. Yeasts and molds were also monitored. Results and discussion. Nectarine firmness was maintained equally in all analyzed groups. The color parameter L∗ showed a tendency to decrease with the increasing length of storage, with lower values in alginate-and alginate + chitosan-coated fruits. The chitosan coating decreased the metabolism activity of fruit during the cold storage without significant changes in the fruit quality (lightness and total soluble solid content). The chitosan coating also controlled the growth of microorganisms. Conclusion. The chitosan coating appears to be a promising preservation alternative and an effective method to improve the quality and shelf life of fresh-cut nectarines in marketing conditions.
... MAP has been revealed to be effective in preventing browning by numerous studies. Browning inhibition and depletion of PPO activity in ready-to-eat apples was detected during storage under MAP ( Soliva-Fortuny et al., 2001). L*-values of Fuerte avocado halves stored in VAC were lower than those stored in MAP throughout 21-day of storage at 7.2°C. ...
Fresh-cut mangosteen (Garcinia mangostana L.) is highly susceptible to quality losses due to damaged cells and tissues and lack of protective skin. The appropriate use of storage condition has extensively been reported to be an effective approach to maintain quality of fresh-cut fruits. The objective of this study was to investigate changes in some quality attributes of fresh-cut mangosteens as affected by storage conditions. Mangosteens were peeled and dipped in a solution consisting of 2% sodium erythorbate + 0.2% calcium chloride for 30 min, and then drained prior to storage under three different conditions, including modified atmosphere packaging (MAP; 5% O2 + 9% CO 2), vacuum packaging (VAC) and air (AIR). In all treatments, moisture content, total soluble solids, pH, titratable acidity, color, firmness and sensory acceptance of fresh-cut mangosteens were monitored at 2-day intervals during 14 days of storage at 4°C. During storage, total soluble solids of fresh-cut fruits stored in AIR sharply increased and were considerably higher than those stored in MAP and VAC. Losses of moisture content and firmness were retarded by storage in MAP and VAC, whereas a rapid decline of both quality attributes was found in fruits stored in AIR. Titratable acidity of MAP and VAC-treated fruits gradually decreased, compared with the slight change in AIR-treated fruits as a result of a greater extent of dehydration. However, pH of fruits in all treatments remained somewhat stable during storage. Lightness (L*) decreased to a larger extent in VAC and AIR-stored fruits, whereas a small decrease in MAP-treated fruits were detected. Fresh-cut fruits with MAP treatment obtained the highest sensory scores, compared with other treatments, throughout the entire period of storage. MAP resulted in the best overall retention of quality attributes of fresh-cut mangosteens during postharvest storage.
... Furthermore, calcium salts have been widely used as firming agents in the fruits and vegetables industry for both whole and fresh-cut commodities (Martín-Diana et al., 2007). On the other hand, calcium treatments have been widely applied in combination with ascorbic acid and thiol-compounds such as cysteine, N-acetylcysteine, and reduced glutathione to prevent enzymatic browning and maintain firmness of fruits (Rojas-Graü, Sobrino-López, Tapia, & Martín-Belloso, 2006;Rojas-Graü et al., 2008;Soliva-Fortuny, Grigelmo-Miguel, Odriozola-Serrano, Gorinstein, & Martín-Belloso, 2001;Soliva-Fortuny, Oms-Oliu, & Martín-Belloso, 2002). Since calcium chloride may impart flavour, the use of other calcium salts such as calcium propionate, lactate, and ascorbate has been recently suggested (Aguayo, Requejo-Jackman, Stanley, & Woolf, 2010;Alandes, Hernando, Quiles, Pérez-Munuera, & Lluch, 2006;Barbagallo, Chisari, & Caputa, 2012;Quiles, Hernando, Pérez-Munuera, & Lluch, 2007). ...
The effects of pulsed light (PL) treatments combined with a quality-stabilizing dip on the quality and antioxidant attributes of fresh-cut 'Golden delicious' apples was studied. Apple wedges were dipped into a solution of 1% w/v N-acetylcysteine and 0.5% w/v CaCl2 and flashed with broad-spectrum light with an overall radiant exposure of 4, 8, 12 and 16J.cm-2. General microbial counts, colour, firmness, phenolic compounds and vitamin C contents were evaluated over 15days at 5°C. More pronounced reductions of the naturally-occurring microbiota were observed as the applied PL-dose increased. The quality-stabilizing pre-treatment effectively prevented browning phenomena on the cut-tissue surface. In addition, browning and oxidation were not promoted in PL flashed samples. Indeed, the initial contents in phenolic compounds and vitamin C were even better maintained than in untreated samples. Treatments of 8 and 16Jcm-2 were most effective for maintaining the quality and antioxidant characteristics. Industrial relevance: Pulsed light technology is an emerging technique with good prospects for the decontamination of foods and food contact surfaces. Application of pulse light treatments for increasing safety and extending microbial shelf life of fresh-cut produce seems feasible. However, their effects on the quality and antioxidant characteristics of fruit need to be evaluated for successfully applying the technology at an industrial level.
... Overall TSS of diced jackfruits for citric acid and ascorbic acid treatments Colour: Changes in a* and L* values have been used to monitor enzymatic browning of cut apples(Soliva-Fortuny et al., 2001). ...
Green mature jackfruits were minimally processed into cubes, dipped in solution of citric acid (0 and 1%) and ascorbic acid (0, 1 and 2%), vacuum packed at 550 mbar atmospheric pressure in 80 μm laminated low density polyethylene vacuum pouches and stored at 2-4°C for 15 days. A control was prepared, using water. Quality parameters like colour, fi rmness, pH, titratable acidity and total soluble solids were determined during storage. Colour parameters indicated increase in browning during storage. A signifi cant increase (P<0.05) in titratable acidity and signifi cant decrease (P<0.05) in pH were observed in all treatments. Texture signifi cantly decreased (P<0.05) in all treatments during storage. Combinations of the browning inhibitors were more effective than when applied individually. Citric acid and ascorbic acid when applied together resulted in non-signifi cant change (P>0.05) in microbial counts, browning, and colour lightness. Treatment of 1% citric acid and 2% ascorbic acid in combination with moderate vacuum packaging and low temperature storage was found most effective in inhibiting browning and deterioration of fresh-cut green jackfruit for up to 15 days.
... Fruits are likely to soften mainly due to hydrolysis of the pectic acids found in the cell walls, with a consequent loss of fluids . The protective effects of calcium chloride treatments against texture loss in fresh-cut apples have been widely reported Soliva-Fortuny, Grigelmo-Miguel, Odriozola-Serrano, Gorinstein, & Martín-Belloso, 2001). In the present work, firmness was maintained as a consequence of the applied treatment and along storage regardless of the applied treatment. ...
Pulsed light (PL) has received considerable attention during the last years as a non-thermal method for the superficial decontamination of fresh foods. The aim of the present study was to evaluate the quality attributes of fresh-cut ‘Golden Delicious’ apples as affected by the combined application of a pulsed light treatment (12 J/cm²) and a gellan-gum based (0.5% w/v) edible coating enriched with apple fiber. Changes in color, firmness, antioxidant capacity, microbial growth and sensory attributes were determined during 14 days of storage at 4 °C. The combined application of coating and PL treatment retarded the microbiological deterioration of fresh-cut apples and maintained the sensory attribute scores above the rejection limits after prolonged storage. Incorporation of fiber in the coating formulation did not curb the sensory acceptability of apple cubes. Results show that the use of a gellan-gum based coating incorporating apple fiber followed by the application of a PL treatment significantly reduced softening and browning of apple pieces through storage.
Our results reveal that PL treatments applied to gellan-coated fresh-cut apples can be used to decontaminate the cut fruit surface without dramatically affecting its fresh-like quality attributes, thus conferring prebiotic potential and contributing to their shelf-life extension.
... PPO activity measurement. Polyphenoloxidase activity was determined according to the method of Soliva-Fortuny et al. (2001). Enzyme activity was assayed spectrophotometrically by adding 3 mL of 0.05 M catechol (Sigma-Aldrich Chemie, Steinheim, Germany) and 75 μL of extract to a 4.5 mL quartz cuvette of 1 cm path length. ...
The work investigate the effect of short-term heat treatment on quality of freshcut nectarines 'Orion'. This treatment may have effects on the fruit beyond their stated purpose because a high temperature stress can trigger changes in plant tissue that affect many physiological processes. These processes include inhibition of ethylene production and other ripening and senescence related processes, induction of defense compounds against pathogens, attack and induction of resistance to other stresses, including low temperature stress. The result of the treatment is to maintain fruit quality following the heat treatment. In this work, a pre-cutting heat treatment at 40°C for 50 min and modified atmosphere packaging (5 kPa O2 and 5 kPa CO2) storage was evaluated. The quality-affecting parameters were evaluated by physical and chemical methods (firmness, colour, pH, soluble solids content and titratable acidity) and by the evaluation of physiological aspects (PPO activity) as well as the changes in headspace gas composition during storage for 11 days at 4°C. Significantly lower concentrations of O2 in the package atmosphere were recorded for heat-treated slices. In contrast, hot water treatment did not reduced firmness loss. Moreover, an insignificant effect of heat treatment and modified atmosphere on chemical composition (total soluble solids and titratable acidity) and colour parameters was observed. Also for the polyphenoloxidase activity no significant changes was recorded.
Apple (Malus domestica) belongs to the family Rosaceae. It is one of the most commonly cultivated fruit in all temperate zones of the world and holds an equally important place in the global economy. Apple is a climacteric fruit and undergoes metabolic changes even after the harvest and thus prone to post-harvest losses. The packaging of apples plays an important role in extending the shelf life of the apples and also maintains the quality during distribution and transport. The prime role of packaging is to contain the food commodity and protect the enclosed product from external damage. But other functions such as traceability, convenience and temper evidence are of secondary importance. Different packaging techniques are employed for the packaging of apples which include both conventional (wooden boxes, corrugated fiber boxes, crates) and non-conventional packaging like modified atmosphere packaging (MAP), active packaging, edible coatings, etc.
ZET Bu çalışmada, Amasya çeşidi elma küplerinin sodyum aljinat (SA) ve stevia kombinasyonları (SAS) içeren çözeltiler ile kaplanması ve modifiye atmosferde (MAP) depolanması sonucu meydana gelen bazı fiziksel ve kimyasal kalite değişimleri incelenmiştir. Araştırma sonucunda; 3 gün depolanan kaplanmış ve kaplanmamış örneklerde (K) ağırlık kaybı gözlenmemiştir. Solunum hızı verileri incelendiğinde K, SA ve SAS örnekleri için sırasıyla oksijen tüketimi 82.95; 26.53 ve 230.56 ml kgs-1. (24sa), karbondioksit üretimi 193.55; 25.21 ve 157.00 ml kgs-1 (24sa) olarak tespit edilmiştir. Depolama başlangıcında titrasyon asitliği değerleri K, SA ve SAS örnekleri için sırasıyla %0.055, %0.118 ve %0.125 ve meyve sertliği değerleri sırasıyla 2.458, 1.665 ve 1.430 N olarak belirlenmiştir. K, SA ve SAS örnekleri için 0.gün/3. gün L* değerleri; 79.84/67.50;77.64/65.65 ve 69.46/42.94, a* değerleri,-1.44/4.04;-3.15/3.94 ve-3.04/18.63 ve b* değerleri 16.66/35.85;19.23/54.01 ve 28.01/46.68 olarak ölçülmüştür. Ayrıca, SA'nın yapışkanımsı özellik katması ve stevianın otsu kokusu ve tadı nedeniyle aljinat ve stevia kombinasyonu film kaplı örnekler duyusal olarak kabul görmemiştir. Sonuç olarak kaplama uygulamalarının solunum hızını azalttığı, titrasyon asitliği değerini arttırdığı ve doku değerini azalttığı belirlenmiştir.
Background:
Calcium is a preservative and firming agent largely used in the table olive industry. Foliar applications of calcium (CaCl2 ) before harvest have been proposed in other fruits to increase firmness and reduce physiological disorders or internal damage. However, there is still a shortage of information regarding the source, the concentration, the number and the period of calcium application onto the canopy to get an effective response of olive quality. In this study, we aimed to investigate the effect of two concentrations of CaCl2 foliar treatments (0.5% and 1.0%), applied at different stages of fruit development (at the end of fruit set, end of pit hardening, and prior to harvesting) on olive quality for two varieties ('Manzanilla de Sevilla' and 'Ascolanta tenera'), cultivated in two different geographical areas (Spain and Italy, respectively).
Results:
The applied Ca concentrations enhanced the fruit calcium content and decreased sodium and potassium. They also improved the mechanical properties without modifying fruit morphology, cuticle thickness nor causing phytotoxicity. Foliar treatments increased the oil content in the pulp (dry weight basis) and the amount of hydroxytyrosol, tyrosol and oleuropein, among other phenols.
Conclusion:
Calcium foliar applications during fruit development effectively increase olive quality. This article is protected by copyright. All rights reserved.
The objective of this investigation was to illustrate the effects of quince seed mucilage (QSM) and ascorbic acid pretreatments to prevent the quality of freeze‐dried banana slices. The studied parameters were moisture content, antioxidant activity, total phenol, color properties, structural properties, and sensory evaluation. Both treatments were effective in protecting total phenolic content and antioxidant activity in dried banana slices (P ˂ .05). The control slices showed greater increase in browning index (BI) and greater decrease in lightness (L*) than pretreated dried samples. Ascorbic acid and QSM treatments can be effective in the control of the enzymatic browning along with maintaining the quality properties of banana chips. Therefore, using of immersion pretreatment with 0.25% QSM and 0.05% ascorbic acid is recommended to prevent enzymatic browning as well as maintain the quality of banana chips before the drying process.
The aim of this study was to develop a quality index and examine the effects of drying apples using three technologies (supercritical CO2 drying, air drying and freeze drying) during a period of six months in ambient conditions. Based on nine quality parameters (textural, colour and sensory properties), a mathematical model for calculating a single total quality index (TQI) of dried apples packed in different types of packaging in normal and modified atmosphere has been introduced.
At the beginning of the study, apples dried in supercritical CO2 had the best scores. After six months, samples dried in supercritical CO2 and freeze dried apples, both packed in polyethylene coated aluminium with 100% N2, scored similarly. The six month shelf-life research revealed that measurable changes occur during the second half of the shelf-life when it is possible to clearly distinguish differences in the overall quality index of different dried apple slices.
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This chapter concerns the modified atmosphere packaging (MAP) technique. MAP can be defined as the enclosure of food in a package in which the atmosphere is modified or altered to provide an optimum atmosphere for increasing shelf life and maintaining food quality. Modification of the atmosphere may be achieved either actively or passively. Gases used in MAP usually consist of O2, CO2, and N2, which are essential for the respiration of fresh fruits and vegetables. Among the gases used in MAP, just CO2 has significant nonselective antimicrobial influence on the product. Furthermore, optimal gas composition and the competitive effect on natural microflora on food pathogens play a significant role in product safety and inhibit foodborne pathogens. MAP, a technique used to extend the shelf life of fresh or minimally processed foods, refers to the development of a modified atmosphere around the product through the use of permeable polymeric films. The shelf life of the packaged products can be extended by 50–200% by using MAP, if the nutritional consequences of MAP on the packaged food products become an issue. Currently, MAP is integrated with several treatments such as heat treatment, irradiation, ozone, and preservatives for preservation of almost all foods in industrialized and developing countries to ensure secure microbial safety, stability, and sensory quality.
High speed data processing for online food quality inspection using hyperspectral imaging (HSI) is challenging as over hundred spectral images have to be analyzed simultaneously. In this study, a real-time pixel based early apple bruise detection system based on HSI in the shortwave infrared (SWIR) range has been developed. This systems consists of a novel, homogeneous SWIR illumination unit and a line scan camera. The system performance was tested on Jonagold apples bruised less than two hours before scanning. Partial least squares-discriminant analysis was used to discriminate bruised pixel spectra from sound pixel spectra. As the glossiness of many fruit and vegetables limits the accuracy in the detection of defects, several reflectance calibrations and pre-processing techniques were compared for glare correction and maximizing the signal to noise ratio. With the best combination of first derivative and mean centering, followed by image post-processing, this system was able to detect fresh bruises in thirty apples with 98 % accuracy at the pixel level with a processing time per apple below 200 milliseconds.
Regular intake of fruits and vegetables has been associated with lower incidences of several diseases. The chapter presents the main phytochemicals contributing to antioxidant potential of fruits and vegetables. The main chemical changes in these compounds due to processing and storage are reviewed, as well as their influence on quality and shelf-life of fruits and vegetables. Furthermore, the most relevant technologies to prevent plant-based products from oxidation are pointed out.
Freshly-cut slices of apple (Malus X domestica Borkh. 'Granny Smith') were dipped in a solution of the nitric oxidedonor compound, 2,2′- (hydroxynitrosohydrazino)-bis-ethanamine (diethylenetriamine-nitric oxide; DETANO) and the development of surface browning was examined during subsequent storage at 0°C. It was found that dipping in DETANO solution inhibited the development of browning, provided the solution was buffered to be slightly acidic. The most effective treatment to inhibit browning, and therefore to extend post-harvest life, was dipping for 60 s in a solution of 10 mg 1 -1 DETANO dissolved in phosphate buffer at pH 6.5. The extension in post-harvest life achieved by DETANO, over untreated slices, was about 170% and the extension in post-harvest life compared to water-dipped slices was about 100%. Solutions of buffered DETANO were found to be stable, as a similar extension in post-harvest life was obtained for five separate batches of apple slices dipped sequentially, five-times for 60 s each, over a 20 min period in the same solution.
Volatile compounds of four table grape cultivars, 'Tengnian', 'Longan', 'Cow's Teat' and 'Emerald non-nuclear' were investigated during postharvest storage by SPME/GC-MS. Using the principal component analysis, relations between volatile compounds were associated with cultivars. The results showed that volatile compounds in the four cultivars of table grapes were different and all changed a lot during postharvest storage. Initially a total of 44 volatile compounds, including alcohols, carbonyls, esters and acids, were found in the four cultivars, while only 25 compounds were detected at the end of storage. In addition, the relevant taste indexes total sugar (°Brix), total acidity (titratable acidity, TA) and sugar acid ratio in different cultivar of grape berry were also determined. It was possible to discriminate the results to monitor the loss of freshness for table grape during storage.
Tissue softening and oxidative browning at cut surface are serious problems with fresh-cut fruit products that can limit shelf life. Different techniques have been developed to extend the shelf life of minimally processed fruits, in particular refrigeration combined with antibrowning agents and calcium salts to reduce loss of firmness. The aim of the present study was to compare a commercial product, Natureseal (AgriCoat, Great Shefford, United Kingdom, control), with 2 different Ca salts (Calcium propionate 1%, w/v, and CaCl2 1%, w/v) combined with citric acid (1%, w/v) on 'Golden Delicious' apple diced, stored 5 days at 1 °C. The results obtained showed that Natureseal was highly effective in maintaining colour and firmness of fresh-cut apples, but also application of CaCl2 + citric acid (CA) could be a good method to preserve the same product for 5 days. On the contrary, application of Ca propionate + CA resulted in acceptable values of firmness, but high browning, sometimes associated with off-flavours. The treatment with CaCl2 + CA could be used in small fresh-cut industries as a cheap alternative to commercial products.
Demand for natural and fresh fruit juice with high quality in terms of nutritional value, physiochemical and sensory characteristics compared to pasteurized products has considerably increased. The objective of this study was to determine the optimal blending conditions to obtain high quality minimally processed melon puree. A Central Composite Design was developed, and ten temperature/time combinations, ranging from 0 to 21°C, and from 5 to 140 seconds were tested. Fresh purees from 4 melon types (Cantaloupe, Galia, Amarillo, and Piel de Sapo) stored at 5 °C for 6 days were compared. For all genotypes, physical (color, consistency), chemical (vitamin C, total phenols, antioxidant capacity, pH, titratable acidity, total soluble solids) and sensorial attributes (browning, smoothness, odor, freshness, sweetness and acidity) were monitored before processing, and at the end of cold storage. Time of blending influenced puree smoothness; fruits blended for about 80 sec reached their optimal homogeneity. For Cantaloupe and Piel de Sapo puree, time of blending significantly impacted on vitamin C (higher reduction for blending longer than 60 sec). Moreover in Cantaloupe puree the increase of process temperature reduced the total phenolic content indicating a possible oxidation. Amarillo melon puree was the most sensitive to color changes; time of treatment significantly affected a*, b*, and Chroma attributes, inducing a high proportion of browning during storage. On the other hand, processing conditions did not affect the quality parameters of Galia puree with the exception of L* value which decreased with the increase of the time of processing. Although quality attributes limiting melon purees shelf-life depended more on the melon type, blending time was the most critical factor affecting nutritional and sensorial losses. A general recommendation for all melon types is to blend melons at low temperatures for not longer than 80 seconds.
The first scientific investigation into effects of a modified atmosphere on fresh fruits and vegetables was published about 200 years ago. However, innovations in modified atmosphere packaging (MAP) for fresh produce are still drawing significant attention from researchers and industry nowadays. This chapter provides an overview of the latest innovations or studies related to MAP for fresh fruits and vegetables based on published literature in the past 5 to 6 years. The results show that the identification of the best MAP practices for individual fresh and fresh-cut fruits and vegetables is still the major focus of research. Active MAP, including antimicrobial packaging, is receiving significant attention. New packaging materials have been evaluated in response to market changes and needs. Limited investigations have been conducted into the intelligent packaging design. These indicate that there are still many challenges and opportunities for the innovations of MAP for fresh and fresh-cut fruits.
An atmosphere of air + 15% CO/sub 2/ caused CO/sub 2/ injury in lettuce (Lactuca sativa L.) in about 10 days at 0/sup 0/C. However, subsequent removal of CO/sub 2/ was necessary for the brown stain symptoms to develop. Under CO/sub 2/ treatment, phenylalanine ammonia lyase (PAL) was induced and its activity correlated well with the development of the injury. Nevertheless, PAL activity did not seem responsible for the differences in susceptibility to CO/sub 2/ injury among the 3 lettuce cultivars included in this study. Prevention of the development of brown stain symptoms by CO/sub 2/ probably was due to its inhibition of phenolics production and the inhibition of polyphenol oxidase activity. 27 references, 10 figures.
The objective of our research was to investigate the effectiveness of various physical and chemical treatments in delaying deterioration of fresh cut pear fruit slices. Slices cut from ripe 'Bartlett' pears were dipped for 1 minute in 1% CaCl2 or in distilled water, held in air, air + 5% CO2 or 0.5% O2 (balance N2), and then evaluated after 2, 4, 7, and 9 days of storage at 5°C for flesh firmness, flesh color and visual quality. We found that: (A), neither the 0.5% O2 nor the air + 5% CO2 treatments had any beneficial effects on retaining flesh firmness or reducing cut surface browning; (B), CaCl2 treated slices had significantly less cut surface browning and better firmness retention compared to untreated slices. Compared to the air control, atmospheres of air + 10% CO2 or air + 20% CO2 caused accelerated tissue browning and necrosis. These data indicate that pear slices are susceptible to high CO2 injury, and the symptoms expressed are similar to those observed in whole fruit. We found that an atmosphere of 0.25% O2 did not effectively reduce cut surface browning of sliced pears. Various concentrations of calcium lactate and/or ascorbic acid were tested on 'Bartlett' pear tissue discs to determine the optimal treatment levels to prevent browning and loss of flesh firmness. We found a combination of 1% calcium lactate and 2% ascorbic acid applied as a dip for 1 minute was the most effective treatment to reduce cut surface browning and firmness loss in pear discs.
Minimally processed fruits and vegetables represent a large and rapidly growing segment of the produce industry, and various nonthermal treatments are being developed to increase their shelf life.
This chapter reviews the present knowledge of the role of oxidizing enzymes in the oxidative discoloration of fruit and fruit products. Several theories have been proposed for the nature and course of enzymic browning, differing considerably in nomenclature as well as in mechanism. Different enzymes having the ability to catalyze oxidation of phenols by molecular oxygen have been mentioned. Some of the oxidizing enzymes are known to be important while others are of doubtful importance. The enzyme systems that are involved in oxidative browning of higher plants with some of their properties have been discussed. The chapter discusses the location and distribution of the polyphenolases and peroxidases in fruit tissues, particularly as affected by maturity, growing conditions and varietal differences. Several hypotheses have been presented as to the function of polyphenolase in plants. With respect to activation and inactivation of phenolases, the chapter discusses the effect of pH, temperature, temperature arid pH on rate of inactivation, salts and inhibitors, sugars, and inactivation by electrical energy. The control of enzymic browning in industry is based on the assumption that this browning is largely due to interaction of the enzyme, polyphenolase, with molecular oxygen and a suitable phenolic substrate.
Minimally processed foods represent a problem from the point of view of microbiological safety, since their processing implies a loss of extrinsic and intrinsic preservation factors. This paper analyzes the microbiological status of minimally processed foods and the prospects to extend their microbiological safety by the hurdles technology. Some issues to be taken into account for this technology are also considered
Inhibition studies by reductant, carboxylic acid, and halide compounds have been carried out on purified apple polypnenol oxidase (PPO). When ascorbic acid, cysteine, or bisulfite was added, a lag period was observed in the color formation whereas oxygen uptake was immediate. The most efficient compound in decreasing the remaining activity was bisulfite followed by cysteine and ascorbic acid. All tested aromatic carboxylic acids were pure competitive inhibitors. For a same substitution, inhibition decreased in the order cinnamic, benzoic, phenylpropionic, and phenylacetic. In each series, inhibition was slightly enhanced by p-hydroxy substitution and greatly decreased by m-methoxy substitution. Inhibition increased as pH was lowered from 5 to 3.6, and the results indicated that the neutral form of the carboxyl group was mainly responsible for inhibition. Sodium halides were inhibitors and the decreasing order was NaF, NaCl, NaBr, and NaI. When pH was varied between 3.5 and 5, fluoride exhibited the same behavior as the carboxylic inhibitors. The Ki for HF was close to 4 μM; thus it was by far the most potent inhibitor of apple PPO. Chloride was a noncompetitive inhibitor, and an equation is given for the variation of the apparent Ki of chloride with pH.
Cut apple pieces coated with double layers of buffered polysaccharide/lipid showed a 50-70% reduction in the rate of CO2 evolution and about 90% decrease in C2H4 as compared with uncoated controls at ∼23°C. This substantial decline in the rates of gas evolution was attributed primarily to the diffusion barrier properties of the lipid layer and secondarily to the inhibitory effect of the ascorbate buffer which contained calcium. Internal CO2 increased and leveled off at concentrations of ∼120 mL/L after 8 h. The internal concentration of C2H4 decreased after an initial rise and reached a low level comparable to that observed in the untreated samples after 24 h. There was ∼50-75% reduction in the internal O2 concentration, while the headspace O2 showed minimal changes. These results suggest that the inhibitory effects of internal CO2 accumulation and O2 depletion may be responsible for the reduced gas exchange in the coated fruit.
Polyphenol oxidase (PPO) activity in 4, 000 × g, 100, 000 × g, 200 × g and soluble fractions of ‘Delicious’ apples was monitored during 28 weeks of controlled atmosphere storage. PPO activity in 4, 000 × g and 100, 000 × g fractions decreased, while that in soluble and 200 × g fractions increased. These shifts in subcellular location occurred sooner in apples which were stored under high CO2 conditions (2.5–6% O2, 8–12% CO2) than those under normal CA conditions (2% O2, 3% CO2). Polyacrylamide gel electrophoresis of 4, 000 × g fractions isolated from ‘Delicious’ apples at harvest showed 2 bands with PPO activity, while stored samples all had 3 bands. Isoenzyme patterns were found to vary in different subcellular fractions.
Foliar sprays of gibberellic acid and ethephon applied to Redhaven peach trees at 21 and 46 days after bloom caused a reduction of enzymatic browning in mature fruit tissue. A replicate from each treatment was analyzed by two-dimensional thin-layer chromatography and polyacrylamide disc gel electrophoresis. Twenty-one polyphenolic compounds were separated. Eight were oxidized by PPO, and were tentatively identified as four chlorogenic acid isomers, three leucoanthocyanidins, and catechin. No differences in qualitative distributions of phenolic compounds were observed which would account for the inhibition of browning in peach tissue. Polyacrylamide disc gel electrophoresis of peach PPO preparations showed the presence of up to 11 multiple forms displaying activity toward catechol. The bands had different substrate specificities and were present in different amounts, but PPO from peaches treated 21 days after bloom appeared to have a catechol reactive band not present in untreated peaches or peaches treated 46 days after bloom. One band from peaches treated 46 days after bloom with 150 ppm ethephon appeared to have decreased substrate specificity toward pyrogallol. Crude PPO preparations from untreated fruit and fruit receiving the 46-day treatments oxidized o-dihydroxyphenols only, and the relative PPO activities varied with treatment. These PPO preparations exhibited two pH optima; pH 4.4 and 6.2 for untreated and GA-treated peaches (46-day treatment), and pH 4.4 and 6.6 for peaches treated with ethephon (75 or 1.50 ppm, 46-day treatment). PPO from the treated peaches had a lower proportion of total activity at pH 4.4 than PPO from untreated peaches.
The physiological consequences of minimal processing are dire. Mechanical injury sets off a complex series of events which result in loss of quality (i.e. color, texture and flavor). Control of this wounding response is a major obstacle that must be overcome. To prolong postharvest life, respiration must be reduced while producing enough energy to maintain the “energized state”. The central roles of membranes and calcium in maintaining quality are discussed.
Polyphenoloxidase (PPO) activity and polyphenol concentrations decreased during maturation and remained relatively constant during cold storage. However, there was no set pattern of changes in degree of browning during maturation and cold storage. Not all cultivars showed the same relationship between degree of browning and enzyme activity. In some cultivars (Classic Delicious, RI Greening, McIntosh and Cortland), PPO activity was directly related to degree of browning while in others (Empire, Rome and Golden Delicious), degree of browning was related more to phenolic concentration. High performance liquid chromatography analysis of the phenolics in apples showed that the types of phenolic compounds in all cultivars were similar and that no one particular compound could account for the differences observed in browning.
The inhibiting effect of ascorbic acid, citric acid and sodium chloride on Polyphenoloxidase (PPO) of Golden Delicious apple cubes was studied.
Dipping in ascorbic acid (0.2-10 g/L range) and in NaCl (0.2-1 g/L range) solutions for 5 min increases the PPO activity. Citric acid solutions (0.2-10 g/L range) have little or no inhibition of PPO.
A 90-100% PPO inhibition was obtained with a 5 min dip in mixtures of ascorbic acid and citric acid (10 + 2 g/L), and of ascorbic acid and sodium chloride (10 + 0.5 g/L).
Fresh sliced apples were dipped in ethanol or cysteine solutions and/or packaged in air or modified atmosphere in order to retard oxidative browning. Modified atmosphere packaging was effective in inhibiting darkening for at least nine days at refrigerated storage conditions. The combination ethanol dip/modified atmosphere packaging resulted as a suitable method in maintaining the original color in apple slices even after exposure to air.
Enzymatic browning in Golden Delicious apple pulp was studied as related to degree of ripeness and temperature (3.5–31°C). Green apple pulp showed the highest rate of browning. This was attributable to differences in ascorbic acid (AA) content and polyphenoloxidase activity in young fruits. The rate of browning determined by CIE L* measurements followed complex temperature dependent kinetics, represented by a multiple linear effects with log time. Equal changes in L* parameter yielded straight lines in a log temperature vs log time plot. Inhibition with AA caused an initial slow rate of browning and a well defined break point associated with exhaustion of antioxidant properties of the AA. The greater the AA concentration the longer the initial period.
A novel method was developed to extend the shelf life and improve the quality of fresh-cut produce. Edible coatings and films were made from apple puree with various concentrations of fatty acids, fatty alcohols, beeswax, and vegetable oil. Apple pieces were coated with solutions or wrapped in preformed films. Changes in moisture content and color were measured during storage. Increasing concentrations of lipids significantly improved the moisture barrier properties of films. Water vapor permeability varied from 69 to 325 g mm/kPa d m2. Apple-based wraps significantly reduced moisture loss and browning in fresh-cut apples. Color was preserved for 12 d at 5 °C. Wraps were significantly more effective than coatings.
Use of Nature Seal™ 1020, a cellulose-based edible coating, as carrier of antioxidants, acidulants and preservatives prolonged the storage life of cut apple and potato by about 1 week when stored in overwrapped trays at 4 °C. Storage of coated apple discs in vacuum-packed trays reduced weight loss and browning compared to overwrapped tray storage. Ascorbic acid delayed browning more effectively when applied in an edible coating than in an aqueous solution. Similarly, the preservatives sodium benzoate and potassium sorbate were more effective in controlling certain microbial populations when applied in Nature Seal than in aqueous solutions, but less effective for others. Adjustment of coating pH to 2.5 gave optimal control of browning and microbial populations. Addition of soy protein to the original cellulose-based Nature Seal formulations reduced coating permeability to oxygen and water vapor. Cellulose formulations with protein were effective in controlling weight loss, especially when the pH of the formulation was raised above that of the isoelectric point, pI, of the protein.
Hurdle technology was developed several years ago as a new concept for the production of safe, stable, nutritious, tasty and economical foods. It advocates the intelligent use of combinations of different preservation factors or techniques (‘hurdles’) in order to achieve multi-target, mild but reliable preservation effects. Attractive applications have been identified in many food areas. The present article briefly introduces the concept of hurdle technology, presents potential applications and gives details on a recently concluded study concerned with this topic and to which scientists from 11 European countries have contributed.
Lightly processed agricultural products present a special problem to the food industry and to scientists involved in postharvest and food technology research. Light or minimal processing includes cutting, slicing, coring, peeling, trimming, or sectioning of agricultural produce. These products have an active metabolism that can result in deteriorative changes, such as increased respiration and ethylene production. If not controlled, these changes can lead to rapid senescence and general deterioration of the product. In addition, the surface water activity of cut fruits and vegetables is generally quite high, inviting microbial attack, which further reduces product stability. Methods for control of these changes are numerous and can include the use of edible coatings. Also mentioned in this review are coating of nut products, and dried, dehydrated, and freeze-dried fruits. Technically, these are not considered to be minimally processed, but many of the problems and benefits of coating these products are similar to coating lightly processed products. Generally, the potential benefits of edible coatings for processed or lightly processed produce is to stabilize the product and thereby extend product shelf life. More specifically, coatings have the potential to reduce moisture loss, restrict oxygen entrance, lower respiration, retard ethylene production, seal in flavor volatiles, and carry additives that retard discoloration and microbial growth.
New strategies for minimally processed foods. The role of multitarget preservation Combined effects in preventing browning reactions in minimally processed fruit
- S M Alzamora
- M S Tapia
- J Welti
Alzamora, S. M.; Tapia, M. S.; Welti, J. New strategies for minimally processed foods. The role of multitarget preservation. Food Sci. Technol. Int. 1998, 4 (5), 353-361. (18) Nicoli, M. C.; Anese, M.; Severini, C. Combined effects in preventing browning reactions in minimally processed fruit. J. Food Qual. 1994, 17, 221-229.
Mass transfer, textural changes and browning reduction in apples processed by combined methods
- O Martín
- A Monsalve-Gonzá Lez
- G V Barbosa-Cá Novas
Martín, O.; Monsalve-Gonzá lez, A.; Barbosa-Cá novas,
G. V. Mass transfer, textural changes and browning
reduction in apples processed by combined methods.
Boletín Internacional de Divulgación. CYTED. 1994, 2,
1-17.
Interpretation of batch reactor data Vamos-Vigyázó, L.; Gajzágó, I. Studies into the enzymatic browning and the polyphenol-polyphenol oxidase complex of apple cutivars
- O Levenspiel
Levenspiel, O. Interpretation of batch reactor data. In Chemical Reaction Engineering; Wiley: New York, 1972; pp 41-47. (25) Vamos-Vigyázó, L.; Gajzágó, I. Studies into the enzymatic browning and the polyphenol-polyphenol oxidase complex of apple cutivars. Confructa 1976, 21, 24.
Revised manuscript received This research was supported by the Departament d'Universitats Recerca i Societat de la Informació of the Generalitat de Catalunya (Spain) through the granting of a scholarship
- Soliva
Received for review February 15, 2001. Revised manuscript received May 25, 2001. Accepted May 30, 2001. This research was supported by the Departament d'Universitats Recerca i Societat de la Informació of the Generalitat de Catalunya (Spain) through the granting of a scholarship. JF010190C 3690 J. Agric. Food Chem., Vol. 49, No. 8, 2001 Soliva-Fortuny et al.
Gajzágó, I. Studies into the enzy-matic browning and the polyphenol-polyphenol oxidase complex of apple cutivars
- L Vamos-Vigyázó
Vamos-Vigyázó, L.; Gajzágó, I. Studies into the enzy-matic browning and the polyphenol-polyphenol oxidase complex of apple cutivars. Confructa 1976, 21, 24.
Official Methods of Analysis of AOAC International. 17th ed.; AOAC International: Gaithers-burg, MD, 2000. (23) U.S. Armed Forces Supply Support Center. Military Standard: Sampling Procedures and Tables for Inspec-tion by Attributes
- W Horwitz
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Changes in apple polyphe-noloxidase and polyphenol concentrations in relation to degree of browning Changes in the activity and subcellular distribution of PPO in Delicious apples during controlled atmosphere storage
- M Y Coseteng
- C Y Lee
Coseteng, M. Y.; Lee, C. Y. Changes in apple polyphe-noloxidase and polyphenol concentrations in relation to degree of browning. J. Food Sci. 1987, 52 (4), 985-989. (27) Barrett, D. M.; Lee, C. Y.; Liu, F. W. Changes in the activity and subcellular distribution of PPO in Delicious apples during controlled atmosphere storage. J. Food Biochem. 1991, 15, 185-199.
New strategies for minimally processed foods. The role of multitarget preservation
- S M Alzamora
- M S Tapia
- J Welti
Alzamora, S. M.; Tapia, M. S.; Welti, J. New strategies
for minimally processed foods. The role of multitarget
preservation. Food Sci. Technol. Int. 1998, 4 (5), 353-361.
Combined effects in preventing browning reactions in minimally processed fruit Improving storage life of cut apple and potato with edible coating
- M C Nicoli
- M Anese
- C Severini
- E A Baldwin
- M O Nisperos
- X Chen
- R D Hagenmaier
Nicoli, M. C.; Anese, M.; Severini, C. Combined effects in preventing browning reactions in minimally processed fruit. J. Food Qual. 1994, 17, 221-229. (19) Baldwin, E. A.; Nisperos, M. O.; Chen, X.; Hagenmaier, R. D. Improving storage life of cut apple and potato with edible coating. Postharvest Biol. Technol. 1996, 9, 151-163.
Heat inactivation of polyphenol oxidase in fruit puré Food preservation by hurdle technology
- K P Dimick
- J D Pointing
- B Makower
- L Leistner
- L G M Gorris
Dimick, K. P.; Pointing, J. D.; Makower, B. Heat inactivation of polyphenol oxidase in fruit puré. Food Technol. 1951, 6, 237. (16) Leistner, L.; Gorris, L. G. M. Food preservation by hurdle technology. Trends Food Sci. Technol. 1995, February, 6, 41-46.
Studies into the enzymatic browning and the polyphenol-polyphenol oxidase complex of apple cutivars. Confructa 1976, 21, 24. (26) Coseteng, M. Y.; Lee, C. Y. Changes in apple polyphenoloxidase and polyphenol concentrations in relation to degree of browning
- L Vamos-Vigyázó
- I Gajzágó
(25) Vamos-Vigyázó, L.; Gajzágó, I. Studies into the enzymatic browning and the polyphenol-polyphenol oxidase
complex of apple cutivars. Confructa 1976, 21, 24.
(26) Coseteng, M. Y.; Lee, C. Y. Changes in apple polyphenoloxidase and polyphenol concentrations in relation to
degree of browning. J. Food Sci. 1987, 52 (4), 985-
989.
Armed Forces Supply Support Center Military Standard: Sampling Procedures and Tables for Inspection by Attributes; MIL-STD-105D; U.S. Government Printing Office (24) Levenspiel, O. Interpretation of batch reactor data
(23) U.S. Armed Forces Supply Support Center. Military
Standard: Sampling Procedures and Tables for Inspection by Attributes; MIL-STD-105D; U.S. Government
Printing Office: Washington, DC, 1964.
(24) Levenspiel, O. Interpretation of batch reactor data. In
Chemical Reaction Engineering; Wiley: New York, 1972;
pp 41-47.
Studies into the enzymatic browning and the polyphenol-polyphenol oxidase complex of apple cutivars
- L Vamos-Vigyázó
- I Gajzágó
Vamos-Vigyázó, L.; Gajzágó, I. Studies into the enzymatic browning and the polyphenol-polyphenol oxidase
complex of apple cutivars. Confructa 1976, 21, 24.
Heat inactivation of polyphenol oxidase in fruit purées
- K P Dimick
- J D Pointing
- B Makower
Dimick, K. P.; Pointing, J. D.; Makower, B. Heat
inactivation of polyphenol oxidase in fruit purées. Food
Technol. 1951, 6, 237.
Official Methods of Analysis of AOAC International
- W Horwitz
- Ed
Horwitz, W., Ed. Official Methods of Analysis of AOAC
International. 17th ed.; AOAC International: Gaithersburg, MD, 2000.