The influence of chitosan on the raspberry quality during the storage process

Abstract

Raspberry is a perishable berry raw material with a high capacity for mechanical and microbiological damage, and therefore, after harvesting, it is necessary to use appropriate technologies to preserve its quality and extend the storage time. This work aimed to study the influence of different concentrations of chitosan solutions on the quality and duration of storage of raspberries under refrigerating conditions. Raspberries were picked at the consumer maturity stage in perforated plastic containers with a capacity of 500 grams. The berries were processed by spraying with 0.5%, 1.0%, and 2.0% chitosan solution, then removing residual moisture. The storage was carried out for twelve days in a refrigerating chamber at a temperature of 2 °С and relative humidity of 95%. The research was performed according to the physical, chemical, and organoleptic indicators, determining the changes in the mass fraction of ascorbic acid, the mass fraction of sugars during storage, taste, aroma, colour, etc. consistency and appearance at the end of storage. It was found that the loss of ascorbic acid in the processed berries was 1.5-3.9 times less than in the reference sample. A similar situation was observed with the mass fraction of sugars, which prevailed 0.9-2.5 times in the processed samples. According to the organoleptic indicators, the samples with a solution concentration of 1.0% and 2.0% were recognized as the best. According to the results of experimental investigations, it was established that pre-processing of berries with chitosan solutions is a promising method to slow down unwanted metabolic processes that take place after harvesting.