Abstract: Considering the sugar content of saccharified purple sweet potato solution and the ability of its acylated anthocyanins to enhance the stability of anthocyanins, this study evaluated the effect of the type of ion exchange resins and flow rate on the deacidification of blackberry juice, and it also investigated the effect of saccharified purple sweet potato solution on the taste of blackberry juice. Changes in the anthocyanin content of blackberry-purple sweet potato juice blend, blackberry juice, and purple sweet potato juice during accelerated storage were compared to explore the effect of saccharified purple sweet potato solution on anthocyanin stability in blackberry juice. The results indicated that eight ion exchange resins could reduce the acid content of blackberry juice and absorption of anthocyanin and soluble solids to different extents. Among these, LXZ-67 resin was found to be the most suitable for the deacidification of blackberry juice. Using this sorbent, the deacidification rate was 55.6% and the retention rates of anthocyanins and soluble solids were 81.4% and 87.1%, respectively. Based on both the production efficiency and the retention rate of anthocyanins, the flow rate should be 20 BV/h. The optimal mixing ratio between blackberry juice and saccharified purple sweet potato solution was 4:1, resulting in a perfectly balanced sour-sweet taste with strong aroma. The rate of anthocyanin degradation in the three juices during accumulated storage could be ranked in decreasing order as follows: blackberry juice > blended fruit juice > purple sweet potato juice, which demonstrates that saccharified purple sweet potato solution could improve the stability of anthocyanins in blackberry juice.

Key words: blackberry juice, deacidification, resins, purple sweet potato, fruit juice blends, anthocyanin stability