不同基质得率速溶普洱茶关键香气物质组成及其热释放规律分析

Analysis of the Compositions of Key Aroma Substances and Their Heat Release Trends of Instant Pu-erh Teas with Different Matrix Yields

摘要:

通过控制浸提温度制备不同基质得率速溶普洱茶。采用感官审评、气相色谱-质谱仪、气相色谱-嗅闻仪及香气提取稀释法对普洱茶及速溶普洱茶香气品质进行分析，并计算稀释因子和气味活力值，从普洱茶中鉴定出关键香气物质13种，从不同基质得率（6.54%、14.61%、20.32%、24.02%、27.41%）速溶普洱茶中分别鉴定出关键香气物质为7、8、8、10、10种。常压水中蒸馏分段回收冷凝液以考察关键香气物质在不同基质得率速溶茶中的释放规律，测定各关键香气物质峰面积，其变化趋势显著拟合（P<0.01=幂函数模型。根据峰面积随基质得率升高的变化趋势，将速溶茶关键香气物质分为5类。I类为增加速率呈先增后降的橙花醇、二氢猕猴桃内酯；II类为释放速率增大的芳樟醇、β-紫罗兰酮、1,2,3-三甲氧基苯、3,4,5-三甲氧基甲苯；III类为释放速率降低的3,4-二甲氧基甲苯、1,2,4-三甲氧基苯；IV类为释放速率呈先降后增趋势的α-紫罗兰酮；V类为与基质得率无关的香叶基丙酮。综上，各关键香气物质随基质得率升高呈不同释放规律。

Abstract:

Instant Pu-erh teas with different matrix yields were prepared by controlling extraction temperature. The aroma quality of Pu-erh tea and instant Pu-erh tea samples with different matrix yields were analyzed by sensory evaluation, gas chromatography-mass spectrometry, gas chromatography-olfactometry and aroma extraction dilution method, and the dilution factors and odor activity values were calculated. 13 key aroma substances were detected in Pu-erh tea, and 7, 8, 8, 10 and 10 key aroma substances were identified from the Instant Pu-erh tea samples with different matrix yields (6.54%, 14.61%, 20.32%, 24.02%, 27.41%), respectively. The condensates were recovered from different stages of distillation in water at atmospheric pressure to investigate the release trends of the key aroma substances in the instant tea with different matrix yields, and the peak areas of the key aroma substances were determined. The changing trends of the key aroma components were significantly fitted to a power function model (P<0.01). Based on the trends of peak area changing with the increasing matrix yield, the key aroma substances of the instant tea were classified into 5 categories: I, nerol and dihydroactinodiolide (their increasing showed an increase followed by decrease; II, linalool, β-ionone, 1,2,3-trimethoxybenzene and 3,4,5-trimethoxytoluene (their release rates increased); III, 3,4-dimethoxytoluene, 1,2,4-trimethoxytoluene and 2,4-trimethoxytoluene (their release rates decreased); IV, α-ionone (its release rate decreased then increased); V, geranyl acetone (which was not associated with matrix yield). In conclusion, all the individual key aroma substances exhibited different release trends with the increase of matrix yield.