PRESERVATION OF BLACKBERRY FRUITS AFTER POST-HARVEST TREATMENT WITH CHITOSAN

Abstract

Blackberries have become very popular all over the world, mainly due to their characteristic taste, nutritional properties and high content of compounds that have a beneficial effect on human health. However, the thin covering tissues of fruits cause juice leakage, accelerated decay, and also make them susceptible to mechanical damage, which can shorten their shelf life. Because of the short shelf life of blackberry fruit after harvest, scientists have explored new storage methods, such as refrigeration and food coatings, to extend postharvest life and preserve fruit quality. At the moment, cold storage is the main way to extend the shelf life of blackberry fruits. The technology of applying edible coatings to the surface of fruits is also applied to it. The use of coatings to form semipermeable barriers that increase fruit quality is aimed at reducing gas exchange and slowing down biochemical processes. To study the effect of chitosan as an edible coating, blackberry fruits were collected at the consumer stage of ripeness, their physical, physico-chemical and organoleptic properties were studied, after which they were processed and then stored. Fruits were treated with chitosan solutions of three concentrations (0.1%; 0.2%; 0.3%) by full immersion for 1 min. The processed fruits were left until completely dry. Dry processed fruits and control were weighed and placed in perforated plastic (PET) containers with a capacity of 500 g and stored in a refrigerator at a temperature of 0 +2°С. Fruits without treatment were considered as control. It was established that the post-harvest treatment of blackberry fruits with a chitosan solution contributed to their better preservation compared to the control, which proves the effectiveness of its use. Pretreatment of blackberry fruits with chitosan slowed down the loss of dry soluble substances by 0.2-0.9%, and organic acids by 0.04-0.12% of the control.