桑椹果汁加工技术研究

Studies on the Juice Processing of Mulberry

本研究对桑椹果汁有机酸HPLC分析,含柠檬酸为1.06％。单宁含量达206rag/100ml。新鲜榨取的果汁,室温下经过6 hr,乙醇和挥发酸(以醋酸计)含量开始变化,12 hr后分别为0.1％和0.2％,是原来的2倍和8倍,果汁出现明显的刺喉现象。桑椹果汁经冻藏解冻后,单宁含量减少了22％,涩味减轻。感官评定含原汁20％的桑椹果汁饮料,评价最高者为酸度0.3％、糖度13Brix的组合,所喜好的酸度范围较窄。高温和金属罐包装贮藏明显促进桑椹果汁花色苷的降解,单宁色变率(CDT％)相应提高。

This study was conducted to determine the organic acids of mulberry juice by HPLC. the results showed that the content of citric acid was 1. 06%. The content of tannin was 206mg/100ml. The contents of alcohol and volatile acid (as acetic acid ) of mulberry juice began change after 6 hr storage at room temperature, and was increased to 0. 1% and 0. 2% respectively after 12hr. It was 2 and 8 times of original value, and the juice was off - odour obviously. The content of tannin decreased for 22% after the juice frozen and thawed, and astringency alleviated. On the preference for mulberry beverage containing 20% juice, preferable acidity and sugar content of the beverage was 0. 3% and 13 Brix respectively, the range of preferable acidity was narrow. Storage at high temperature and packed with metal can could accelerate the degradation of anthocyanin obviously, and % color due to tannin increased in the same time.