Understanding the Effects of Various Edible Coatings on the Storability of Fresh Cherry

摘要

In this work, cherries, which have a very short shelf life, were packaged after being coated with various edible coatings [whey protein isolate (WPI), chitosan and shellac]. The changes in gas composition, weight loss, Brix, pH, electrical conductivity and firmness were measured periodically up to 11 days after harvest to compare the effects of the applied coatings. Fourier transform near-infrared (FT-NIR) spectroscopymeas-urements were also taken individually. After storage, the gas composition within trays was about 1-10% O_2 and 14-47% CO_2. The lowest weight loss (25.56%) was observed in the shellac-coated cherries, while the highest loss (48.58%) occurred in the control group. Coated cherries exhibited a significantly lower pH and electrical conductivity than the uncoated ones. The control group presented the highest total soluble solid (TSS) values (21.29) and shellac coating had (17.25) the lowest. At the end of storage, the highest ascorbic acid (AA) content was 0.64 mg/100 ml in the shellac-coated cherries, and the lowest AA content of 0.40 mg/100 ml was measured in the control group. Firmness was maintained by coating, especially with shellac (3.734 N), whereas the control had the lowest firmness measured (2.138 N) at the end of storage. There were differences between the absorbance spectra for the coated and control cherries at the end of storage. This research concludes that shellac coating is more effective in reducing the respiration rate and maintaining the quality parameters of cherries than chitosan and WPI coatings. Major benefits of coatings were observed in lessening the weight-loss process and in maintaining firmness, which were also supported by the FT-NIR measurements.