Shohreh Zivdar; Naser Alemzadeh Ansari; Hossein Fereydoni; Hojjatollah Rabbani Nasab; Mohammad Hossein Razzaghi
Abstract
IntroductionCitrus is one of the most important horticultural products that is mainly produced in the subtropical regions of the world. Citrus fruits are susceptible to a number of ...
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IntroductionCitrus is one of the most important horticultural products that is mainly produced in the subtropical regions of the world. Citrus fruits are susceptible to a number of fungal diseases that cause significant losses in the citrus industry in the post harvest stage. Worldwide, diseases have been primarily controlled for many years by the application of conventional fungicides. However, human health risks and environmental contamination associated with chemical residues and the proliferation of resistant strains of the pathogens are major problems associated with the continuous and widespread use of conventional post harvest fungicides. Heat and UV radiation treatments are the most common physical means used to control post harvest diseases of fresh fruits. The aim of this study was to investigate the effects of UV-C radiation and Hot Air Flow (HAF) treatment on decay control and some biochemical properties in Thomson navel oranges at cold storage. Materials and MethodsIn this experiment, the effects of heat treatments (37 °C for 24 hours), UV radiation (7.92 kJ / m2) and combination treatment (HAF*UV) on the storage life of Thomson oranges were investigated. The statistical model of factorial experiment was in the form of a completely randomized design in which two factors of storage time and treatments were considered. After treatment, the fruits were stored at 5 ° C for 90 days during the storage period, the percentage of decay, fruit weight loss, and some biochemical properties and enzymatic activity were investigated. Statistical analysis of data was performed using SAS software and the mean data were compared using Duncan's multiple range test at a five percent probability level using MSTATC software.Results and discussion:In this study, the effect of UV-C radiation and hot air flow on the rate of decay, weight loss, biochemical characteristics and activity of a number of enzymes involved in the oxidation of Thomson Novel orange fruit was investigated.Treatments included control (no application of any treatment) radiation (UV-C radiation with an intensity of 7. 98 KJ m2), hot air (hot air 37 °C for 24 hours) and combination (UV-C + hot air) which in The four storage times of zero, 30, 60 and 90 days were examined in factorial format based on a completely randomized design. The results showed that radiation and heat treatment effectively reduced fruit rot . the lowest and highest percentage of cumulative rot was observed in the combined treatment with an average of 3.8% and the control treatment with an average of 12.7%, respectively.The control treatment and the combined treatment with the average of 5.68 and 2.94, respectively, had the highest and lowest fruit weight loss. During fruit storage, TSS, TA, TSS/TA and pH increased and TA decreased The amount of ascorbic acid in fruits treated with hot air flow with an average of 35.54 mg per 100 g of fresh material was higher than the control treatment with an average of 30.67 mg per 100 g of fresh material. Antioxidant activity increased at the beginning of the period, however, the treatments did not have a significant effect on inhibiting DPPH radical activity in fruit flesh The amount of total phenol, peroxidase and polyphenol oxidase enzyme activity in fruit flesh under the influence of heat treatment, initially increased with the period, which the enzyme activity decreased with increasing storage time. According to the evaluated traits, heat and combination treatment succeeded in reducing the rate of rot and increasing the biochemical properties of the fruit during storage, so it can be considered as a suitable practical option.
