响应面法优化高品质茶叶木炭烘焙参数

Response Surface-optimized Tea Charcoal Baking

【目的】优化茶叶的木炭烘焙工艺,为高品质茶叶木炭烘焙提供理论参考依据,为茶叶烘焙智能化提供基础。【方法】利用模糊数学矩阵分析原理,以模糊感官综合评价分作为响应值,烘焙温度、摊平厚度、烘焙时间为自变量,设立三因素三水平试验组合,拟合线性回归模型,通过响应面法对茶叶木炭烘焙工艺进行优化,并通过实际烘焙试验进行验证;测量茶叶主要香气成分含量、主要生化成分含量,分析试验工艺对茶叶品质的影响,进一步验证二次回归模型的可靠性。【结果】结合实际修整后的最佳组合参数:烘焙温度为82℃、摊平厚度为3 cm、烘焙时间为126 min;茶叶主要香气成分有反-橙花叔醇、法尼烯、植物醇、吲哚,其含量多少与香气等级相符;主要生化成分有茶多酚、可溶性糖、氨基酸、咖啡碱,其含量多少与汤色、滋味等级相符,感官评价结果与评价体系相吻合。【结论】建立的高品质茶叶木炭烘焙工艺的感官评价标准合理,感官评价模型可靠性强,试验结果能够真实地反映木炭烘焙最佳工艺。

【Objective】Charcoal baking in processing tea was optimized.【Methods】Fuzzy sensory evaluation score was used as the criterion in a 3-factors-3-levels response surface experiment to optimize the temperature(A),leaves spreading thickness(B),and time(C)of the tea baking with burning charcoal.A linear regression model was established for the process.Actual and theoretical sensory evaluations on the resulting tea were compared to determine the effect of the baking on tea quality and reliability of the quadratic regression model in predicting the result.【Results】The optimized charcoal baking spread tea leaves 3 cm thick and held at 82℃for 126 min.The main aromatics in the baked tea included trans-nerol,farnesene,plant alcohol,and indole in contents corresponded to the rated grade.The major biochemicals were tea polyphenols,soluble sugars,amino acids,and caffeine in contents reflected the color and taste of the brewed tea.The sensory panel and the fuzzy evaluation on the tea yielded agreeable results.【Conclusion】The fuzzy sensory evaluation model appeared to be applicable for determining the process conditions of tea charcoal baking.