THE INFLUENCE OF CHITOSAN FILMS ON SOME QUALITY INDICATORS OF STRAWBERRY BERRIES BEGINS DURING REFRIGERATION

Abstract

Strawberry (Fragaria ananassa) is among the most perishable berries and is vulnerable to physical injuries and fungal invasion. One of the main approaches to extend the storability of this perishable commodity is to apply edible coatings on the surface followed by cold storage. Edible coatings can be used as a protective barrier to reduce respiration, retard microbial growth and improve physical integrity be reinforcing the tender skin structure. The objective of the research was to the investigate the effect of chitosan treatment on weight loss, respiratory rate, pH and microbiological damage of strawberries during refrigerated storage. To achieve this goal berries were treated with 0,1; 0,3; 0,5% chitosan solution and storage at t 0+2°С for 14 days. Uncoated fruit were used as control samples. Strawberries that showed any sign of surface mycelia development were considered decayed. Results were expressed as percentage of infected strawberries. Results have shown that storage duration of strawberries in the control variant was 8 days, in the experimental variants was 14 days, which is 1,7 times longer. An important indicator of preservation is natural weight loss. The criteria for the end of storage was the weight loss no more than 5%. The experimental results show for strawberries in the control variant, the average weight loss on the 8th day of storage was (6,11%). The weight loss of treated berries were (2,88 – 4,81%). Chitosan treatment changer the respiration rate of strawberries. At the end of storage the respiration rate was (1,15 – 1,8%). Chitosan treatment berries had less damage to fungal diseases. Chitosan edible coatings can be an effective method to improve the quality and extending the shelf-life of strawberry. It approved to be good barrier, thus preventing the weight loss by evaporation and delaying microbiological damage

Keywords

• strawberries
• chitosan
• post-harvest processing
• edible coatings