Quality changes of fresh grapes and blueberries during cold storage

Abstract

The degradation of fresh fruits during cold storage was studied by measuring changes of various physical and physicochemical parameters during storage at temperatures 0, and 10°C. Red grapes and cultivated blueberries were used as objects of this study. Degradation of fruits was monitored by measuring physical structure, and content of bioactive components in fruits. The anthocyanin content was determined by direct spectrometric determination, and the radical scavenging activity was detected by direct spectrometric determination of standard free radical leftover after reaction with alcohol extracts from the samples. The texture was investigated by rupture test. Yield point, rupture point, young modulus and deformation work were measured by texture analyser. Samples were taken at the starting point of the storage period, at 3, 7, 14, and 21 st day. Results showed that the content of biologically active components is increasing at the initial stage of storage, and starts to decrease at second phase, after second week of cold storage. Changes of the texture were also seen from our results, the fruits were wasted their crispiness and their stickiness was grown.