با همکاری انجمن علمی منظر ایران
نوع مقاله : مقالات پژوهشی
نویسندگان
1 گروه فیزیولوژی و فناوری پس از برداشت، پژوهشکده مرکبات و میوه‌های نیمه‌گرمسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش.
2 گروه فیزیولوژی و فناوری پس از برداشت، پژوهشکده مرکبات و میوه‌های نیمه‌گرمسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش
3 گروه فناوری و مدیریت تولید، پژوهشکده مرکبات و میوه‌های نیمه‌گرمسیری، موسسه تحقیقات علوم باغبانی، سازمان تحقیقات، آموزش و ترویج
کلیدواژه‌ها
عنوان مقاله English
نویسندگان English
Introduction:
Postharvest treatments with waxes or chemical fungicides have been used for many years in citrus sorting units to preserve fresh fruit, control postharvest decay, and increase fruit storable. Fungicides have a short-term efficiency due to the appearance of fungicide-resistant pathogens. In addition, consumer concerns have increased about their adverse effects on the environment, human, and animal health. Therefore, fruit production should be safety and healthy, without chemical additives, in accordance with the principles of sustainability and the need for environmental protection. Nano chitosan, due to its excellent biocompatibility, biodegradability, low toxicity, and ability to coating, can be used to preserve fruit quality and inhibit Penicilliums.
Materials and Methods:
In this experiment, uniform fruits were divided into four groups after harvest. Then, each group was subjected to coating and protective treatments and transferred to two conditions: Common storage and Cold storage. The treatments included 1. Nano chitosan (2gr/L), 2. Thiabendazole fungicide (1.5 per 1000 L.), 3. Wax coating (Xedamix, 1 per 1000 L.) and 4. Control. Each treatment consisted of three boxes containing 30 fruits as replication. For each treatment, one box of fruit containing 15 fruits was also considered for the evaluation of rind spots at the end of storage. The fruits were stored in two types of cold storage: cold storage at a temperature of 5°C and 85% RH and common storage with average temperature of 7 to 10°C (depending on the environment temperature) and 60-70% RH for three months. On days 0, 30, 60, and 90, by sampling from both storages, fruit quality characteristics including peel thickness, weight loss, juice percentage, technology index, TSS, TA, TSS/TA, vitamin C, L*, a* and b* values, hue angle, chroma, CCI, rate, percentage and severity of rind spot and sensory properties.
Results and Discussion:
The results showed that the percentage of weight loss during both storages, regardless of the type of treatment, was near to 6% in the first 30 days, but its amount decreased on day 60 and then increased again in the 30 days leading up to the end of storage. Fruits treated with wax lost less water (3.05%). The peel thickness of fruits treated with Nano chitosan was 3.36 mm less than other treatments. The juice percentage of fruit was not affected by the applied treatments. In all treatments, the ratio of fruit juice to weight was high in the first 30 days of storage (average 41%) but continued to decrease until the end of storage. The technological index of all treated and control fruits in cold and common storages were between about 4 and 5. Nano chitosan-treated fruits did not differ significantly from the control and wax coating in terms of TSS (11.28%) but were lower than (11.7%) fungicide-treated fruits, significantly. Nano chitosan treatment did not have a significant effect on TA compared to the control and other treatments. Regardless of the treatment type, TA in both storages decreased from 1.35% at the beginning of storage and reached 1.18% at the end of cold storage and 0.96% in common storage. Nano chitosan treatment did not have a significant effect on TSS/TA compared to the control and other treatments. In cold storage, this ratio increased significantly from 8.4 to 10.01 in the first 30 days, but remained constant until the end of storage. In both storage conditions, vitamin C levels were high at the beginning of storage and on day 60 but showed a decreasing trend during storage. The a* value in the Nano chitosan treatment was as high as the control, but significantly reduced at the fungicide and wax treatments. Fruits treated with Nano chitosan, like the control, had a higher hue angle than the other two treatments in common storage. The hue angle of the fruit skin in both storage conditions and in all treatments gradually decreased from the beginning to the end of storage. In common storage, fruits treated with Nano chitosan had a higher color index (CCI) than the control. The lowest percentage of spots was related to the wax treatment with 8.33%. In common storage, the percentage of spots in the Nano chitosan and wax treatments was zero, which was much lower compared to the control and fungicide treatments. At the end of storage, it was found that the fruits under wax treatment, although they had a desirable appearance, but had a significant decrease in their sensory properties. Fruits treated with Nano chitosan, while preserving their sensory properties, also had overall fruit acceptability at the end of storage.
Conclusion:
Fruits treated with Nano chitosan did not differ significantly from other treatments in terms of weight loss, juice percentage, technological index, titratable acid and vitamin C. Also, the TSS level as control and wax was lower than the fungicide treatment. The peel color index was the highest, as in other treatments, compared to the control. The percentage and severity of rind spots in common storage was zero but was moderate in cold storage. Fruits treated with Nano chitosan maintained their sensory quality properties well. Nano chitosan is a natural compound and is considered an alternative to chemical coatings. Due to its role in preventing the development of fungal diseases, it can be used by orchard and cold storage owners.
Acknowledgement
This article is derived from a research project with the approved number 47-17-33-134-991294, which was commissioned and supported by Nano Pouya Polymer Tis Company and it became researched in the Citrus and Subtropical Fruits Research Institute (Ramsar). The financial support of both units is gratefully acknowledged.
کلیدواژه‌ها English
