摘要
为了研究茶叶内部可能存在的苦味抑制效应,采用定量感官分析法比较了蔗糖、D-葡萄糖酸钠、L-谷氨酸钠、乳酸锌和腺苷-5′-磷酸(AMP)对咖啡因、EGCG(表没食子儿茶素没食子酸酯)和茶汤的苦味掩盖作用。结果表明,低浓度的蔗糖(5 mmol.L-1)、葡萄糖酸钠(5 mmol.L-1)和谷氨酸钠(2 mmol.L-1)对苦味掩盖不明显,在高浓度下这3种物质的苦味掩盖效果明显,但对茶汤滋味的协调性产生不利影响。乳酸锌(0.5～1.5 mmol.L-1)和AMP(0.2～0.6 mmol.L-1)对苦味的掩盖作用均明显,但是乳酸锌即使在低浓度下涩感也较强,加重茶汤涩感;AMP是最为有效的苦味掩盖剂,可有效掩盖茶汤的苦味,且对茶汤滋味协调性没有明显影响。此外,还建立了茶叶中AMP的HPLC测定方法,1/15 mmol.L-1的磷酸盐缓冲体系(pH7.0,含5 mmol.L-1四丁基溴化铵,5%甲醇)为主要流动相,35℃条件下C18柱分离,254 nm测定AMP的方法。茶叶中AMP的含量(0.23～0.32 mg.g-1)尚未达到明显掩盖茶叶自身苦味的水平。
In order to study the possibility of self-inhibition on bitterness in tea brews,the masking agents as sugar,sodium D-gluconate,sodium L-glutamate,zinc lactate and adenosine-5′-phosphoric acid（AMP） on bitterness of caffeine,EGCG（epigallocatechin-3-O-gallate） and tea were studied by quantitative sensory assessment.The results showed that the treatments of low concentrations of sucrose（5 mmol·L-1）,sodium D-gluconate（5 mmol·L-1） and sodium glutamate（2 mmol·L-1） had no obvious effect on bitterness inhibition respectively.Although the supplements of high concentration of the three compounds showed significant effects on bitterness suppression,those high concentrations led to uncoordinated tastes.Further,Zinc lactate（0.5-1.5 mmol·L-1） and AMP（0.2-0.6 mmol·L-1） were used to masking test and it showed that they were both significant on the masking of bitterness.However,zinc lactate itself showed obvious astringency even in low concentration（0.5 mmol·L-1） which had strengthened the astringent taste.AMP had showed as the optimum masking agent for tea bitterness.Moreover,a RP-HPLC method with C18 column for AMP tests in tea was established.The HPLC conditions were optimized as the mobile phase pH 7.0,1/15 mmol·L-1 phosphate buffer containing 5 mmol·L-1 tetrabutyl ammonium bromide and 5% methanol,detecting wavelength 254 nm and temperature 35℃.The amounts of AMP in tea were all at low levels（0.23-0.32 mg·g-1） which were far below the valid level for masking bitterness.
出处
《安徽农业大学学报》
CAS
CSCD
北大核心
2010年第4期682-687,共6页
Journal of Anhui Agricultural University
基金
现代农业(茶叶)产业技术体系建设专项资金(农科教发[2008]10号)资助
