Food Technology
Karim Mandahakki; Hamid Hassanpour
Abstract
IntroductionDue to the high rate of respiration, strawberry is prone to water loss, mechanical damage and fungal decay post-harvesting, which may reduce its shelf life (Yan et al., 2019). Food waste is an important global challenge that estimated about 30% of the world's agricultural land. Every year, ...
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IntroductionDue to the high rate of respiration, strawberry is prone to water loss, mechanical damage and fungal decay post-harvesting, which may reduce its shelf life (Yan et al., 2019). Food waste is an important global challenge that estimated about 30% of the world's agricultural land. Every year, about 9.5 million tons of food is lost in the post-harvest phase of agriculture crops (Bishop et al., 2021). Post-harvest storage of strawberry at low temperature without using other combined treatments may reduce its shelf life due to its highly perishable nature. Therefore, in addition to low temperature storage, other post-harvest techniques have also been reported to increase the shelf life of strawberry fruits after harvest. One of these techniques is using chemicals (Kahramanoglu et al., 2019).Glutathione is present in various plant tissues in concentrations of 2 to 3 mM and plays an important role in many cellular processes such as cell differentiation, enzyme regulation, cell signaling and cell death and acts as an antioxidant. (Diaz-Vivancos et al., 2015). During the experiment, spraying GSH on strawberry plants increased the amount of total flavonoids and ascorbic acid in the harvested fruits, and the results showed that the application of GSH can increase the shelf life of strawberries. (Ge et al., 2019). It has been reported that application of glutathione after harvesting okra has reduced browning and prevented its weight loss, which has created a suitable market for it, also GSH has increased the level of total phenol and the activity of ascorbate peroxidase enzyme and reduced the level of ROS and malondialdehyde, which can increase the shelf life of okra in cold storage after harvesting (Li et al., 2023).Materials and MethodsSabrina strawberry fruit was obtained from a commercial greenhouse located in Urmia in the full maturity stage. The fruits were transported to the laboratory of Horticultural Sciences Department of Urmia University, observing the necessary precautions to prevent mechanical damage. The fruits were separated in terms of size and uniformity, so that the fruits were divided into 5 groups of 15, one group as a control group and 4 groups treated with different concentrations of L-glutathione (4, 16, 32 and 64 mM respectively). After drying, the treated fruits were placed in zipped nylon bags and stored for 15 days in a cold room at ± 0.5 °C and a relative humidity of 90-95%. Also, three biological replicates at each time interval were included in the analysis. Samples obtained at each of specified time were placed to evaluate skin color, titratable acidity, soluble solids, taste index, pH, weight loss, total antioxidant capacity, total phenol content, and polyphenol oxidase enzyme activity.Results and DiscussionThe results of variance analysis showed that the effect of GSH treatment after harvesting, the effect of storage and the interaction between them differently affect each of the studied indicators. In terms of color, no significant effect was found. The effect of storage (p≤0.01) and post-harvest treatment (p≤0.05) were significant on TA trait and its highest value was observed in 10 days of storage with 32 mM. In terms of antioxidant capacity (p≤0.05) and PPO activity (p≤0.01), the effect of GSH treatment after harvest was significant, and the highest amount was observed in 16 and 64 mM treatment, respectively. Also, the effect of storage time (p≤0.05) and the effect of GSH treatment after harvesting (p≤0.01) were significant in the trait of total phenol content, and the highest amount was observed in 15 days of storage and 64 mM treatment. However, both the storage (p≤0.01) and the post-harvest GSH treatment (p≤0.05) effects on fruit weight reduction were significant and the lowest weight loss was observed in 5 days of storage and 64 mM treatment. There were no significant changes in indices such as TSS, taste index and pH.ConclusionAccording to the obtained results, the treatment of 64 mM GSH is the best concentration of GSH to increase the shelf life of harvested strawberry fruits in cold storage.Author ContributionsManda-Hakki: conceptualization, data management, financing, research and review, resources, validation, visualization, writing-main draft, Hassanpour: formal analysis, methodology, project management, software, supervision, Writing - review and editingFunding SourcesPart of this project was financially supported by Urmia University.AcknowledgementWe appreciate and thank all those who were with us in this project, especially the officials of Horticulture Laboratory, Faculty of Agriculture, Urmia University.
Hadis Cheraghi; Fardin Ghanbari; Mehdi Saidi
Abstract
Introduction: Button mushroom (Agaricus bisporus L.) is one of the most popular and widely consumed edible mushrooms that is grown all over the world. However, button mushrooms have a short shelf life of about 3 to 4 days after harvest and lose their commercial value within a few days due to browning ...
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Introduction: Button mushroom (Agaricus bisporus L.) is one of the most popular and widely consumed edible mushrooms that is grown all over the world. However, button mushrooms have a short shelf life of about 3 to 4 days after harvest and lose their commercial value within a few days due to browning of the tissue, water loss, aging and microbial attack. Tissue browning is caused by the activity of polyphenol oxidase (PPO) in plastids on phenolic compounds in the vacuoles as a substrate. Therefore, enzymatic browning is intensified by the loss of membrane integrity due to aging and tissue deterioration and as a result of physical connection between the enzyme and the substrate. The use of some techniques such as the chemicals and physical treatments gives promising results in delaying Browning and increasing the shelf life of edible mushrooms. Cinnamic acid (CA) is an organic acid that occurs naturally in plants and has low toxicity and a wide range of biological activities. Cinnamic acid and its derivatives are widely used in food industry. This compound acts as an inhibitor of polyphenol oxidase activity. On the other hand, cinnamic acid in low concentration has been proposed as an activator of the antioxidant system and its positive effects on reducing the effects of environmental stresses in various plants have been proven in several experiments. Therefore, in the present study, the effect of cinnamic acid treatment on reducing the browning of the tissue and maintaining the quality of white button mushrooms in the post-harvest period has been investigated. Materials and Methods: Treatments included exogenous application of cinnamic acid at four levels (control, 100, 200 and 400 μM trans cinnamic acid) and storage time at five times (0, 4, 8, 12 and 16 days after storage). Cinnamic acid treatment at the mentioned concentrations was applied by top application 24 hours before mushroom harvest. Distilled water was used for control treatment. At the time of picking, infected, very large and small mushrooms were removed and the same mushrooms with a cap diameter of 40 to 45 mm were collected for each experimental treatment. After harvesting, the mushrooms were placed in a polyethylene box covered with cellophane and after weighing, they were transferred to an incubator at 4°C. In the post-harvest period, different traits were measured with a four day interva. Results and Discussion: The results showed that by increasing storage time, the activity of polyphenol oxidase and peroxidase increased and consequently the browning of the tissue also had an increasing trend. Also, with increasing storage time, weight loss percentage, hydrogen peroxide and malondialdehyde increased and total phenol and total antioxidant capacity were decreased. The use of cinnamic acid treatment in all three concentrations (100, 200 and 400 μM) reduced the activity of peroxidase and polyphenol oxidase activities and reduced tissue browning. The application of cinnamic acid also improved the quality traits of edible mushrooms such as total phenol, total antioxidant capacity and visual quality index. These findings suggest that application of cinnamic acid, especially at a concentration of 400 μM, could have the potential of inhibiting tissue browning and thus maintaining the mushrooms quality at the postharvest period
Maryam Mandegari; Abdol Majid Mirzaalian Dastjerdi; Laleh Mosharaf; Maryam Tatari
Abstract
Introduction: Pomegranate (Punica granatum L.) is an important horticultural fruit that is generally very well adapted to the Mediterranean climate. Arils are the edible part of this fruit, being rich in anthocyanins and bioactive compounds such as phenolic compounds and flavonoids which act as antioxidants ...
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Introduction: Pomegranate (Punica granatum L.) is an important horticultural fruit that is generally very well adapted to the Mediterranean climate. Arils are the edible part of this fruit, being rich in anthocyanins and bioactive compounds such as phenolic compounds and flavonoids which act as antioxidants and free radical scavengers. Susceptibility to chilling injury in pomegranate fruits is a major limiting factor in storing fruits at low temperatures. Below 5 °C, pomegranate fruits show symptoms such as surface pitting, browning, discoloration, and decay. The control of temperature is an effective tool for extending the shelf life of fresh horticultural products. Oxidative stress, as caused by an excess of reactive oxygen species (ROS), is usually associated with chilling injury in fruits. Nitric oxide (NO) is an important gas molecule, the involvement of which in many physiological processes can protect plant cells against oxidative stress by reducing the accumulation of ROS. Postharvest studies have shown that the application of NO gas can extend the storage life of a range of horticultural produce by delaying ripening or senescence. Due to the high number of pomegranate cultivars in Iran, limited amounts of information exist on how the qualitative characteristics of arils in the Malas pomegranate can be affected by nitric oxide and different temperatures during storage. The Malas cultivar comprises a large share of pomegranate exports from Iran. In this research, the positive effects of nitric oxide were examined on reducing the chilling injury and maintaining the fruit quality of pomegranate. The application of this treatment at different concentrations and different storage temperatures led to variable effects on the qualitative characteristics of arils in the Malas pomegranate. Materials and methods: Malas pomegranate fruits were harvested commercially from Isfahan Province and were transferred to the Food Industry Laboratory of Isfahan Natural Resources Research. The fresh arils were separated from fruit tissues and were immersed in solutions of nitric oxide (0, 5 and 10 μM/L) for 5 min. After draining, the arils were placed in packaging films of polyethylene and were immediately stored at 2, 4 and 8 °C for 21 days. Several parameters were measured every 7 days during the storage time. These were the weight loss, total soluble solids, titratable acidity, TSS/TA, acid ascorbic, total phenol, total anthocyanin content, antioxidant activity, MA, ion leakage, POD, PPO activity and sensory evaluation. The current study was carried out as a factorial assay and was based on a completely randomized design with three replications. Data were processed by ANOVA using the SAS software version 9.4. Significant differences were identified using Duncan’s test at 1% probability level. Results and discussion: Results showed that the total anthocyanin content, total phenol, antioxidant activity, and titratable acidity decreased during storage time. The control group and the treatment with low temperatures significantly reduced the qualitative characteristics of arils during storage. The water content of arils treated with 5 and 10 μM nitric oxide was maintained considerably for 21 days during storage. According to these results, unlike titratable acidity and ascorbic acid which decreased in both treated and untreated fruits, there was an increase in the total soluble solids and POD activity of arils during storage. However, nitric oxide reduced the rate of these changes, whether it be the decrease or increase in the measured parameters. During the experiment, the control samples showed lower values of quality regarding all parameters. The use of nitric oxide in fruits reduced lipid peroxidation and ion leakage significantly, whereas the antioxidant activity increased. The decrease in ion leakage was observed most notably in fruits that were treated with 10 μM nitric oxide. Furthermore, low temperatures managed to disrupt the metabolic balance of reactive oxygen species, leading to the accumulation and destruction of antioxidant enzymes. In the present study, exogenous treatments with nitric oxide at 5 and 10 μM significantly reduced the lipid peroxidation content and electrolyte leakage of arils being stored at cold temperatures, compared to untreated arils. Nitric oxide suppressed the activity of polyphenol oxidase (PPO) and preserved the physical appearance and the internal quality of pomegranate arils. The decrease in phenolic compounds (29.32%) and antioxidant activity (39.91%), besides the increase in lipid peroxidation (38.37%) and ion leakage (36.98%), caused deteriorations in the appearance and organoleptic properties of the control samples. To alleviate these problems, nitric oxide has beneficial effects on maintaining the anthocyanin content of pomegranate arils by partially inhibiting PPO enzyme activity during storage. It prolongs the postharvest life, helps to preserve the quality of pomegranate arils, suppresses the formation of ethylene, reduces the respiratory rate and controls weight loss, in addition to maintaining the firmness of fruits. Delaying the changes in peel color and TSS are also considered as useful effects of nitric oxide on pomegranate arils. Nitric oxide impeded the process of senescence by slowing down PPO-related activities, thereby maintaining the total phenolic content of pomegranate arils.In conclusion, the application of nitric oxide was observed to reduce ion leakage and PPO activity in pomegranate arils, while also maintaining the quality of arils. Ultimately, the use of 10 µM nitric oxide at 8 °C can be suggested as the most optimum treatment herein.
Hassan Sabbaghi; Aman Mohammad Ziaiifar; Mahdi Kashani-Nejad
Abstract
Introduction: L-Ascorbic acid (vitamin C) is the most important vitamin in terms of nutrition. Ascorbic acid is a thermolabile (heat-sensitive) compound that can be degenerated aerobically or anaerobically. The degradation rates of ascorbic acid differ with the changes in environmental conditions such ...
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Introduction: L-Ascorbic acid (vitamin C) is the most important vitamin in terms of nutrition. Ascorbic acid is a thermolabile (heat-sensitive) compound that can be degenerated aerobically or anaerobically. The degradation rates of ascorbic acid differ with the changes in environmental conditions such as temperature and water activity. It is ascertained that the other nutrients residing in a food can be preserved in case the Vitamin C content is preserved. Thus, the compound is considered as the nutritional quality index during the food processing. The simultaneous infrared dry-blanching and dehydration (SIRDBD) with intermittent heating method is a novel process in which the temperature is kept constant. Over-blanching causes product quality decline and nutrients, especially vitamins, deterioration. Therefore, the precise process conditions (time and temperature) are specified with the objective of preventing over-processing. To do so, such factors as access to the specific center temperature, access to a certain level of enzymatic inactivation and preservation of a given ratio of Vitamin C should be taken into account. This is subject to the biophysical properties of fruits and slices size and shape. The aim of this study was to determine the appropriate operating conditions for blanching step. For this purpose, the effect of irradiation temperature and thickness of the product on the destruction of polyphenol oxidase (enzymatic browning agent) and vitamin C were investigated.
Materials and methods: Apple slices (Golden Delicious variety) were prepared with thickness of 5, 9 and 13 mm and 20 mm in diameter. Irradiation was carried out at three constant temperatures of 70, 75, and 80 ° C. The central temperature of the product was recorded during processing. To evaluate the enzymatic activity of polyphenol oxidase (PPO) and its effect on the product color, apple slices were removed from the device in 2- minute intervals and the process was continued till the time no sign of color change stemming from catechol reagent addition was observable. Vitamin C content measurement was carried out with 30- minute intervals during drying till apple slice reaches constant weight. It was performed based on titration by the use of 2, 6-Dichlorophenol-Indophenol (DCPIP). To calculate the browning index (BI) due to PPO activity, image acquisition was made with the use of a flatbed scanner. The treated samples were placed on the scanner and then a black box was utilized so as to prevent the interferences of the peripheral lights and light reflections. The images featured a 300 dpi quality and were saved in TIFF-24 bit format. Color analysis of the obtained images was carried out in color spaces L*a*b* by the use of “color space convertor” pelagin in ImageJ software, version 1.6.0. Statistical analyses were carried out in SPSS software, version 19. To do so and in order to assess the time required time for the blanching, there was made use of completely randomized design (CRD) in factorial format (32) considering two factors, namely thickness (in three levels) and temperature (in three levels). The statistical analyses of the vitamin degradation kinetic constant (k), as well, were conducted based on randomized complete block design (RCBD) in the course of which the temperature and thickness were considered as the block and the treatment, respectively. Mean comparisons were undertaken based on Duncan test in a 95% confidence level (P
Mohammad Reza Asghari; Raheleh Jami; Alireza Farokhzad
Abstract
Introduction: Nowadays, due to mechanization of life, consumers need of food which they spent little time for preparation, So Fresh cut industry is growing rapidly in the world. These products had strong growth since 1940, and in 2013, most sales of fresh cut fruit related to apples, against 21.8 percent. ...
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Introduction: Nowadays, due to mechanization of life, consumers need of food which they spent little time for preparation, So Fresh cut industry is growing rapidly in the world. These products had strong growth since 1940, and in 2013, most sales of fresh cut fruit related to apples, against 21.8 percent. Minimal processing operations include grading, washing, sorting, slicing, chopping and then packaging of fruit or vegetables. Since these operations result in quality loss, due to water loss, softening, microbial contamination, increased respiration, ethylene and tissue browning. To extend the shelf life of fresh cut fruit, some effective techniques including, low temperature, modified atmosphere packaging, nanotechnology and coating have been applied. Nowadays, edible coatings are used for fresh cut fruits to reduce respiration and control physiological changes. Nano-scale ingredients lead to increase surface to volume ratio so increases the activity of the particles and their impact, the other hand use of calcium compounds in the fruit can be caused strength of the cell wall and bridges between pectin polymers in cell wall and cell membrane so the activity of digestive enzymes decreases. Materials and methods: Golden delicious apples were selected for uniform size and appearance in a commercial orchard in Urmia. Fruit disinfected with disinfectant solutions for 10 min. half of the apples in the laboratory before cutting were immersed in nano calcium carbonate solution at concentrations of 0, 0.1, 0.2, and 0.4 % for 4 min and the other half of the fruit after cutting treated with the same concentrations of nano calcium carbonate for 2 minutes. Control fruit were treated with distilled water. Fresh cut were dried at 20 ᵒC for 15 minutes and placed in plastic containers (8 slices per a dish), In Refrigerator equipment at 1±0.5ᵒC and relative humidity 90-95% for 20 days. Results and discussion: Fresh cut apples coated with nano calcium carbonate reduced the enzyme activities. So that in treated samples compared to control samples polyphenol oxidase activity was reduced. Also, antioxidant activity and catalase levels were higher than the treated fruit during storage. As a result, fresh cut apples coated with nano calcium carbonate can be used as an easy way to increase the shelf life of apples in cold storage.
Mina Seifzadeh; Aliasghar Khanipour
Abstract
This project was carried out in order to Study of possibity of uses from 4 hexyresorcinol for prevention of melanosis in cultured shrimp.Treatments including of samples processed with 0.15% concentration of 4 hexylresorcinol and control samples. The samples were kept at -18oC. Bacterial, chemical and ...
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This project was carried out in order to Study of possibity of uses from 4 hexyresorcinol for prevention of melanosis in cultured shrimp.Treatments including of samples processed with 0.15% concentration of 4 hexylresorcinol and control samples. The samples were kept at -18oC. Bacterial, chemical and sensory examinations were carried out for a period of six months. Statistically significant difference was observed in peroxide value, free faty acids, thiobarbotouric acid and trimethylamin in test samples compared with the control samples during storage period (P
