Quality and antioxidant activity changes during low-temperature storage of strawberry fruits.

摘要

There was only a slight change in colour (L*, a* and b* values) during storage at 0 degrees C of fresh strawberry cultivars Prarajathan No. 50 and 72 (different breeding lines) grown in northern Thailand. The rate of loss of firmness was greater in No. 50 than in No. 72 for the total storage period. The total soluble solids (TSS) content decreased in No. 50, but there was only a slight change in No. 72. Titratable acidity decreased substantially, and reducing sugar content increased at the same rate during low temperature storage of both cultivars. Vitamin C content was reduced after 16 and 12 days storage in No. 50 and 72, respectively. There was a decrease in phenolics and in anthocyanin content, but there was an increase in antioxidant activity in these cultivars. The observed negative correlation between both phenolics and anthocyanin content to antioxidant activity during low temperature storage indicated that these fruit antioxidants did not play a major role in increasing antioxidant activity. It can be concluded that an increase in antioxidant activity was probably due to an increase in antioxidant enzymes (such as superoxide dismutase, peroxidase and catalase) and other fruit antioxidants during the senescence stage, rather than vitamin C, phenolic compounds or anthocyanin..