采用高效液相色谱法测定琯溪蜜柚果汁中柚皮苷及其降解产物的变化,研究黑曲霉DB056柚苷酶制剂脱苦琯溪蜜柚果汁的优化条件;并且在此优化条件下,使用该柚苷酶制剂对琯溪蜜柚鲜柚汁、浑浊浓缩柚汁和澄清浓缩柚汁进行脱苦。结果表明:黑曲霉DB056柚苷酶制剂催化琯溪蜜柚果汁中柚皮苷水解成普鲁宁和柚皮素;该柚苷酶制剂在40~55℃、果汁自然pH值条件下对琯溪蜜柚鲜柚汁进行脱苦,酶用量90U/mL、处理时间80min,柚皮苷脱除率达到89%;处理不同浓缩程度的浑浊浓缩柚汁,脱苦率约为80%左右。结果说明黑曲霉DB056柚苷酶制剂对琯溪蜜柚果汁具有良好的脱苦作用。
High performance liquid chromatography(HPLC) was used to determine naringin and hydrolysates in Guanxi pomelo juice to explore the optimal conditions of bitterness removal for Guanxi pomelo juice by the naringinase from Aspergillus niger DB056.Under optimized conditions,the naringinase was used to debitter Guanxi pomelo fresh fruit juice,cloudy concentrated juice and clarified concentrated juice.The results showed that the optimal debittering conditions were natural pH,40-55 ℃treatment temperature,90 U/mL naringinase amount and 80 min treatment time.Under the optimal debittering conditions,the naringin in pomelo juice could be effectively degraded into prunin and naringenin by the enzyme and the removal rate of naringin was up to 89%;meanwhile,the debittering efficiency of cloudy concentrated juice was up to 80%.Therefore,naringinase has an excellent debittering capability for Guanxi pomelo juice.