金刺梨原汁脱涩及其与梨-南瓜复配果蔬汁的研制

目的:解决金刺梨原汁口感酸涩，开发口感良好、酸甜适口且稳定性高的金刺梨复配果蔬汁。方法:首先采用明胶吸附或β-环糊精包埋法进行原汁脱涩处理，其次拟采用鲜榨梨汁和南瓜浆进行复配，并进行巴氏杀菌条件优化。结果:加入0.5%明胶可使金刺梨原汁中单宁脱除率达到63.00%。根据感官评价结果和基本理化指标，确定复配果蔬汁的优化配比为金刺梨汁:梨汁:南瓜浆体积比为34:40:26；在85 ℃下处理3 min能够使复配汁中细菌总数降至1.38 lg CFU/mL，酵母和霉菌未检出（<1 CFU/mL）；其可溶性固形物含量、总酸含量分别下降了2.33%和5.98%，超氧化物歧化酶（SOD）保存率为67.8%，还原型维生素C（V_C）和总V_C的保留率分别为78.72%和80.30%；但热处理后复配果汁发生了一定程度褐变。结论:通过对金刺梨原汁进行脱涩及果蔬汁复配得到酸甜适度的金刺梨复配果蔬汁，可为金刺梨的深加工提供技术参考。

Research on Deastringency of Raw Chestnut Rose Juice and Preparation of Its Blended Fruit-Vegetable Juice with Pear and Pumpkin

Objective: To solve the problem of sour taste in raw chestnut rose juice, and to develop its blended fruit-vegetable juice with good taste quality, sweet and sour taste and high stability. Methods: The raw chestnut rose juice was first deastringented with gelatin adsorption or β-cyclodextrin embedding, and then it was blended with freshly prepared pear juice and pumpkin pulp, finally the pasteurization parameters of blended fruit-vegetable juice were optimized. Results: By adding 0.5% gelatin, the tannin removal rate of raw chestnut rose juice could reach 63.00%. According to the sensory evaluation results and basic physical and chemical indexes, the optimal ratio of compound fruit and vegetable juice was determined as follows: The volume ratio of golden thorn pear juice:pear juice:pumpkin pulp was 34:40:26. As the blended fruit-vegetable juice was subjected to pasteurization at 85 °C for 3 min, total viable bacteria of it was1.38 lg CFU/mL, and the counts of yeasts and molds were under the detect limitation (<1 CFU/mL). There were 2.33% and 5.98% reduction of soluble solid content and total acid of the blended juice, respectively. And 67.8% superoxide dismutase was retained. The retention rates of reduced vitamin C (V_C) and total V_C were 8.72% and 80.3%, respectively. However, a viable browning of blended juice occurred after pasteurization. Conclusion: A blended chestnut rose fruit-vegetable juice with good taste and high nutritional value was developed by deastringency treatment of raw cloudy juice and further more blending with proper fruit-vegetable juice or pulp. The obtained results would provide primary technical suggestions for the deep processing of chestnut rose juice in the future.