Abstract: With the aim of effectively removing tannin from Rosa roxburghii juice, reducing astringency, and enhancing its taste, chemical precipitation was applied, and ginger protein was used as the tannin remover. Besides, tannin removal rate and vitamin C(VC)retention rate were adopted as the key analytical parameters. In addition, single-factor experiment and orthogonal test were used to determine the optimal tannin removal process for ginger protein. The results were as follows:(1)The optimal conditions for removing tannin from R. roxburghii juice with ginger protein were a liquid-solid ratio of 30:1.2(mL:g), R. roxburghii juice pH of 3.0, a stirring temperature of 5 ℃, and a stirring time of 30 min.(2)According to orthogonal test analysis, the degree of influence of various factors on removing tannin from R. roxburghii juice was liquid-solid ratio > stirring temperature > R. roxburghii juice pH > stirring time.(3)Under the optimal process conditions, the tannin removal rate and VC retention rate were(47.451±0.608)% and(75.904±1.244)% respectively.(4)Under the optimal process conditions, juice transmittance rate increased from(8.44±0.662)% to(92.47±0.397)%, the astringency of R. roxburghii juice was significantly reduced, and its flavor was improved. In summary, this study provides a novel approach and a new technological route for solving common key technical problems faced by the deep processing industry of R. roxburghii juice and also provides a certain technical reference for exploiting ginger resources comprehensively.

Key words: Rosa roxburghii juice, ginger protein, tannin, chemical precipitation, vitamin C(VC)

摘要： 为有效脱除刺梨果汁(Rosa roxburghii juice)中的单宁,降低其涩味改善口感,该研究以刺梨果汁为对象,采用化学沉淀法,以姜蛋白为单宁脱除剂,并以单宁脱除率和维生素C(VC)保留率为考察指标,采用单因素实验和正交试验优化姜蛋白脱除单宁工艺确定最优工艺。结果表明:(1)姜蛋白脱除刺梨果汁单宁的最优工艺条件为液固比30:1.2(mL:g),刺梨果汁pH 3.0,搅拌温度5 ℃,搅拌时间30 min。(2)由正交试验分析可知,各因素对刺梨果汁脱除单宁的影响程度依次为液固比>搅拌温度>刺梨果汁pH>搅拌时间。(3)在最优工艺条件下,单宁脱除率为(47.451±0.608)%,VC保留率为(75.904±1.244)%。(4)在最优工艺条件下,果汁透光率从(8.44±0.662)%提高到(92.47±0.397)%,涩味明显改善,同时丰富了刺梨果汁风味。该研究结果为解决刺梨果汁深加工行业面临的共性关键技术问题提供了一个新思路和新工艺技术路线基础,也为拓展生姜资源的综合利用奠定了一定技术基础。

关键词: 刺梨果汁, 姜蛋白, 单宁, 化学沉淀法, 维生素C(VC)