Food Technology
Ali Akbar Shokouhian; Shahriyar Einizadeh; Mehrdad Dashti
Abstract
IntroductionCherry, with the scientific name Prunus avium L., is one of the most important stone fruit trees in temperate regions, belonging to the Rosaceae family and the Prunoideae subfamily. Edible coatings are thin layers of materials that are used on the surface of the product and are an alternative ...
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IntroductionCherry, with the scientific name Prunus avium L., is one of the most important stone fruit trees in temperate regions, belonging to the Rosaceae family and the Prunoideae subfamily. Edible coatings are thin layers of materials that are used on the surface of the product and are an alternative to protective wax coatings. Chitosan is a coating that has a polysaccharide structure and is composed of glucosamine and N-acetylglucosamine units and is obtained from the shell of crustaceans such as crabs and shrimps. Clear, odorless, non-sticky gel with high and firm absorption power is extracted from the inner parts of aloe vera plant leaves. Between this gel and the outer skin of the leaf, there are special cells that contain a yellow liquid and when this liquid dries, aloe vera juice is produced. This gel is completely healthy and compatible with the environment, and its pH is about 4.5, which can replace various fruit coatings in the post-harvest stage. The purpose of this research was to investigate the combined effect of aloe vera gel and chitosan in maintaining the quality characteristics post harvesting and increasing the shelf life of Lombard cherry fruit. Materials and MethodsLambert black cherry fruit was obtained from the garden complex of Moghan Agriculture and Animal Husbandry Company located in Pars Abad city of Ardabil province. they were immediately transferred to the Postharvest Physiology Laboratory, Department of Horticultural Sciences, Faculty of Agriculture and Natural Resources, Mohaghegh Ardabili University, for the desired treatments.This study aimed to extend the shelf life of cherry fruit with two edible chitosan coatings (0, 0.5, 1, 1.5% w/w) and aloe vera gel (0, 15%, 30%, 45% w/w) was performed as factorial in a completely randomized design in three replications. The measured parameters were soluble solids, vitamin C, total acidity, anthocyanin, starch, weight loss and firmness of fruit tissue that were evaluated at harvest time and 45 days after harvest. Results and DiscussionThe results of analysis variance showed that the effect of time had significant on cherry fruit flavor (P<0.01). The use of Aloe vera gel had a significant effect (P<0.01) on soluble solids, starch, firmness, fruit flavor and also weight loss (P<0.05). The effect of chitosan treatment also were significant on total soluble solids, starch, firmness, and fruit flavor (P<0.01). Moreover, Interaction effect of aloe vera gel and chitosan treatments on total soluble solids, starch, firmness, and fruit flavor were significant (P<0.01) during at storage time. The compare means showed that the ratio of soluble sugars to total acid was increased. The highest soluble solids and their ratio to total acid were obtained as a result of the using of 45% aloe vera gel with 0.5% chitosan coating. Combining of aloe vera gel with 30% and 45% concentrations with chitosan at 1% and 1.5% were able to maintain better firmness of fruit tissue compared to other treatments during storage time.The highest residual starch in the fruit was obtained in using aloe vera gel treatments at concentrations of 15%, 40% and 45% with 1% chitosan during storage. Also, the use of aloe vera gel (all three levels) was exceled compared to control on fruit weight loss. By reducing the activity of ethylene, chitosan causes a delay in ripening and aging and as a result reduces the firmness of the fruit. Aloe vera gel reduces the activity of pectin methylesterase, poly-galactronase and beta-galactosidase. These enzymes destroy the cell wall and soften the fruit. ConclusionThe interest in using edible coatings to maintain the optimum quality of fruits during the marketing and storage process has increased. Edible coatings can act as a barrier, thereby reducing quality loss, inhibiting gas exchange, controlling respiration rates, and preventing the growth of microorganisms that cause fruit decay. The results clearly indicated the preservation of the quality of cherry fruit with the use of edible coatings compared to the control. The use of the treatment combination of chitosan at a concentration of 1.5% with aloe vera at a concentration of 45% has had a positive and significant effect to maintain the quality of cherry fruit after harvesting. Therefore, the use of this treatment combination is recommended to increase the storage life and maintain the quality of Lambert cherry fruit during the storage period.
Neda Derakhshan; Ali Akbar Shokouhian; Bahram Fathi achachelooee
Abstract
Introduction: Peach fruit is considered to be a part of the fragrance fruits in terms of respiratory behavior, which is why it quickly becomes corrosive at normal temperature. Shelf life of peach is limited because of weight loss due to water loss and physiological abnormalities such as browning and ...
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Introduction: Peach fruit is considered to be a part of the fragrance fruits in terms of respiratory behavior, which is why it quickly becomes corrosive at normal temperature. Shelf life of peach is limited because of weight loss due to water loss and physiological abnormalities such as browning and tissue alteration. The Aloe Vera gel is a polyester coating and has an elastic property that is easily soluble in water and covers the entire area around the product to a similar extent. This gel acts as a protective layer on the product and protects the cells below the protective layer against mechanical damage and also prevents the loss of juices. Polyamines are a group of low-molecular-weight, naturally-occurring compounds with linear nitrogen groups found in almost all organisms and play a role in a wide range of physiological processes in plants, animals and microorganisms. The purpose of this experiment was to investigate the effect of Putrescine and Aloe Vera gel on the prolongation of the post-harvest life of peach fruit.
Materials and methods: Peach fruits (Prunus persica L.), the redtop cultivar at commercial maturing stage, when 80-50% of the fruits were painted, Harvested from the gardens of Moghan Agro Industry & Industry Co., located in Pars Abad city and after transferring to the laboratory, coating treatments as factorial based on completely randomized design with coating treatments in four levels of Putrescine (0, 2, 4, and 6 milli molar) and Aloe-vera gel treatments in four levels (0%, 15%, 30%, and 45%) in three time periods (15, 30 and 45 days) and three replicates with total of 144 experimental units was carried out. The fruits at -1° C and humidity of 95-90% were kept in cold storage. The pH of the juice were measured by a Digital pH Meter, soluble solids at room temperature was read by hand-made refractometer on a graded column. To measure total acid, titration was performed using 0.1% sodium hydroxide solution and the results were expressed in grams of malic acid in 100 grams of fresh weight. Measurement of vitamin C was done by titration with Decolor phenol Indole Phenol and Meta phosphoric acid and its amount expressed as mg of ascorbic acid in 100 grams of sample. The total phenol content was measured by the Folin- Sioculto method. The acetone method was used to measure carotenoid. Flavonoids were measured by acid ethanol method. The data of this study were analyzed using SPSS (9.1.3) and comparison of mean of treatments with LSD-test at probability level of 5%. Charts were also drawn using Microsoft Excel software.
Results & Discussion: Based on the analysis of variance table, the triple effects of Putrescine, aloe vera and time treatments in all indices had a significant effect at 1% probability level. Analysis of variance showed the lowest pH at combined treatment of 6 mM putrescine and 30% Aloe-vera gel. Also, the most titratable acidity was observed at combined treatment of 6 mM putrescine and 15% Aloe-vera gel and the most total soluble solids was observed at combined treatment of 2 mM and 45% Aloe-vera gel. Highest levels of vitamin C were observed at combined treatment of different levels of Aloe-vera gels at 6 mM putrescine. The most carotenoid levels was for combined treatment of 6 mM putrescine and 30% Aloe-vera gel and the most flavonoids was for combined treatments of 6 mM putrescine and 45% Aloe-vera gel. The pH peach juice increased during storage, due to the breakdown and decomposition of organic acids in the respiration process. The organic acids during storage are low due to their consumption during respiration and have a downward trend. The amount of soluble solids in fragrance fruits, such as peaches, increases during storage, when using putrescin significantly reduced the changes in soluble solids. The treatment of polyamide fruits slowly reduces the amount of total soluble solids that can be delayed in the production of ethylene and the ripening of fruit. It seems that the effect of polyamide treatments on their ability to maintain acidic conditions and the total acid content of the fruit extract, is related to their ability to compete with ethylene and delay in the ripening process. The amount of phenol over time has been increased. Phenol content of fruits and vegetables can be reduced or increased, which depends on storage conditions. With increasing maintenance period, the activity of PEL enzymes increases in different stages of harvesting, so that it has the highest amount at the time of commercial maturation. Based on the results of this study, it was observed that co-application of Putrescin coated treatments with aloe vera gel maintains biochemical parameters in terms of storage of peach fruit. Generally, the combination of 6 μM Putrescin and 30% Aloe Vera combination therapy had the best effect among other treatments in maintaining the traits in tomato fruit.
