Optimization of de- astringency technology on Rhodomyrtus Tomentosa( Ait.) Hassk juice by using response surface analysis

Activated carbon combined with ultrasound and gelatin method were used on de-astringency technology of Rhodomyrtus Tomentosa( Ait.) Hassk juice. For the determination of tannin removal rate and anthocyanin retention,the de-astringency effect were compared.The experimental results showed that gelatin method was the better.And based on the single-factor experiment,the de-astringency technology were optimized by using BoxBehnken central combination design. The results showed that the optimum de-astringency conditions were as followed: gelatin dosage 1.2%,temperature 51℃,reaction time 42 min,and the tannin removal rate reached to48.72%,andanthocyanin retention reached to 53.11%.