Color stability of fruit yogurt during storage.

This article describes the evaluation of the anthocyanins stability in yogurts with strawberry, sour cherry, and blueberry fruit preparation during 8-week storage period under refrigerated condition. The differences in anthocyanin degradation rate and color changes between stirred yogurts and fruit-on-the-bottom yogurts (fruit preparation was on-the-bottom of package) were compared. Anthocyanin content in fruit yogurts showed a significant decreased during the storage, especially for the first 2 weeks. There were differences in the rate of pigment degradation between yogurt obtained from a different species of fruit. The half-life of the pigments in stirred yogurt with the preparation of strawberry, sour cherry, and blueberry was found to be 5.5, 6.7, and 19.0 weeks, respectively. The addition of fruit preparation on the bottom of yogurt could be used to reduce the pigment degradation during storage. The half-life of anthocyanin in fruit-on-the-bottom yogurts was 39-63% higher than in the blending samples. A significant alteration in the pigment profile during storage of blueberry yoghurt was observed. The proportion of malvidin-glucosides and acylated anthocyanins increased with time of storage, with a concomitant decrease in proportion of petunidin, delphinidin and peonidin derivatives.