نوع مقاله : مقاله کامل علمی پژوهشی
نویسندگان
1 دانشجوی کارشناسی ارشد فناوری‌های پس از برداشت، گروه مهندسی بیوسیستم، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
2 استادیار گروه مکانیک بیوسیستم- دانشگاه علوم کشاورزی و منابع طبیعی ساری- مازندران
3 دانشیار، گروه مهندسی بیوسیستم، دانشگاه علوم کشاورزی و منابع طبیعی ساری، ساری، ایران
چکیده
کلیدواژه‌ها
موضوعات
عنوان مقاله [English]
نویسندگان [English]
Background and Objectives: Ripeness of loquat fruit is accompanied by many changes in its chemical composition, which greatly reduces its shelf life. Shelf life prediction models have significant practical implications and theoretical importance in terms of controlling storage conditions and decision-making processes for fruits.
Material and Methods: The loquat fruit was collected from one of the orchards of Mazandaran province in Babol city. At the time of fruit harvesting, care was taken to harvest fruits that were the same in size and maturity. The samples were divided into two general groups. Samples that were stored at ambient temperature (25℃) and samples that were stored at refrigerator temperature (4℃). Each group of samples that were arranged inside the package were exposed to cold plasma for three times of 5, 10 and 15 minutes. The lid of the container was kept open during this time. A series of samples were also considered as controls without cold plasma treatment. Cold plasma with a voltage of 20 kV was generated by copper electrodes using the surface electric barrier (DBD) method at a power of 60 watts and a frequency of 60 Hz and was directly blown into contact with the samples. The quality characteristics of loquat fruit, including resilience, weight loss, soluble solids, ripening index, color indices, total acidity, flavonoid and total phenol content, pH, and vitamin C content, were investigated during the storage. SPSS v.20 and Design Expert v.12 software were used to model, predict, and optimize the treatment and storage conditions. The modeling aimed to find the main factors and their interactions. In the models, the cold plasma treatment time factor (A), storage temperature (B) and number of storage days (C) as well as the interactions AB (time × temperature), AC (time × days) and BC (temperature days) were considered as effective variables.
Results: Finally, it was found that linear models had the best predictive power of the response and showed the greatest fit with the laboratory data. Also, the regression analysis of the predicted data with the model and laboratory data showed a high correlation (R2). To perform optimization with the help of Design Expert software, the pH level was set at the target value of 3.6, Brix in the range of 10 to 12, total acidity in the range of 0.32 to 0.65, ripening index at the lowest level, flavonoid and total phenolic compounds at the highest level, elasticity in the range of 0.04 to 0.35, browning index at the lowest level, color indices L*, a*, b*, H* and C* in the normal range of the control fruit, and weight loss at the lowest level. The importance of all indices for optimization was determined to be medium. In this way, it was determined that for the specified conditions that can maintain the quality indices at the level of the control fruit on the first day, the combination of cold plasma treatment for 15 minutes and storage at 4 °C can be used with a desirability of 0.61, and under these conditions, the fruit is able to maintain the best conditions at the level of the first day of harvest until day 18.
Conclusion: These results could provide a suitable solution for gardeners, sellers, and fruit exporters for post-harvest storage of sensitive fruits such loquat. Also, these results could provide growers, sellers, and fruit exporters with a suitable solution for post-harvest storage of sensitive fruits such as Japanese quince.
کلیدواژه‌ها [English]
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