Influences of chitosan coatings on functional compounds of sweet cherries

In this study, sweet cherries were coated with four chitosans (1%) [two of them produced from shrimp waste from Marmara Sea in Turkey (Chitosan-1, Chitosan-2) and two of them commercially produced (Commercial-1 and Commercial-2)] which have different deacetylation degree, and molecular weight (Chitosan-1, deacetylation degree: 78.20%, molecular weight: 182 kDa; Chitosan-2, deacetylation degree: 84.95%, molecular weight: 127 kDa; Commercial-1, deacetylation degree: 81.22%, molecular weight: 273 kDa; Commercial-2, deacetylation degree: 75.12%, molecular weight: 407 kDa) and stored at 4 °C for 25 days, and 20 °C for 15 days. Changes in the total phenolic content, antioxidant capacity, total anthocyanin content, ascorbic acid, total pectin content, firmness, and colour values were evaluated. The results revealed that Chitosan-1 had the highest firmness value; Chitosan-2 showed the highest total anthocyanin and total phenolic content and Commercial-1 exhibited the highest antioxidant capacity and ascorbic acid content at 4 °C. Furthermore, it was found that Chitosan-1 demonstrated the highest total phenolic content; Chitosan-2 displayed the highest total anthocyanin; Commercial-1 had the highest firmness value and C-2 exhibited the highest ascorbic acid content at 20 °C. In conclusion, each tested chitosan coatings have different effects on different quality attributes at different storage temperatures.