香草醛/硫酸法测定柿子单宁含量条件的优化  

Determination of persimmon tannin content by H_2SO_4-Vanillin assay

作　　者：杨依姗[1] 李春美[1] 陈美红[1] 

机构地区：[1]华中农业大学食品科技学院,武汉430070

出　　处：《食品科技》2010年第12期267-271,共5页Food Science and Technology

基　　金：国家自然科学基金项目(30972398);教育部重点项目(109115)

摘　　要：采用以硫酸为香草醛法的介质测定柿子单宁含量,考察了硫酸浓度、香草醛浓度、反应时间、反应温度、含水量、光照等因素对柿子单宁与香草醛显色反应的影响。结果表明,硫酸-香草醛法测定柿子单宁含量的适宜条件为:1.0 mL提取液,2.5 mL 1%香草醛的甲醇溶液以及2.5 mL 5 mol/L H2SO4的甲醇溶液,混匀后于30℃水浴保温20 min后即可测定A500。在实验过程中应严格控制水分,而光照对该反应影响不大。采用此法测定柿子单宁含量稳定性和重现性好,方法回收率高。Vanillin assay was carried out in H2SO4 medium to determine the content of condensed tannin in persimmon extract.Several parameters affecting the precision and accuracy of vanillin assay including H2SO4 concentration,vanillin concentration,reaction time,reaction temperature,water content,sunlight were studied.The results showed that the proper reaction conditions were as the following： the medium comprised of 1 mL of sample,2.5 mL of 1% vanillin solution in methanol,and 2.5 mL of 5 mol/L H2SO4 solution in methanol,and the reaction was carried out at 30 ℃ for 20 min（measured at 500 nm）.Water content should be strictly controlled during the reaction,and there was no significant difference at the 5% level between vanillin reaction undergone in the dark and that undergone in diffuse sunlight.Assessment of the method by statistics proved its high stability,reproduction quality,and recovery.

关 键 词：柿子单宁 香草醛 条件优化 影响因素 

分 类 号：TS207.3[轻工技术与工程—食品科学]