[关键词]
[摘要]
为探明电磁滚筒变温/热风耦合干燥技术对绿茶栗香形成的影响,本研究考察了不同的滚筒变温组合、干燥时长、是否耦合热风这些关键工艺参数对绿茶栗香形成的影响,利用红外辅助顶空固相微萃取(IRAE-HS-SPME)结合气相色谱-质谱技术(GC-MS)对香气组分进行定性定量分析,采用多元统计分析手段进一步筛选栗香关键差异性化合物。结果表明,以单芽嫩度为制备原料,当电磁滚筒变温组合为180 ℃/170 ℃/160 ℃,耦合110 ℃热风干燥6 min时制得的绿茶栗香品质最佳。此外,通过偏最小二乘法-判别分析(PLS-DA)建立了栗香绿茶的有效判别模型(R2Y=0.997,Q2=0.774);基于VIP>1和p≤0.05,筛选出27种关键差异性化合物;进一步采用层次聚类分析(HCA)确定其在栗香和非栗香茶样中的分布规律,发现27种香气物质在栗香绿茶中的含量普遍高于非栗香绿茶。另外,原料嫩度也会影响绿茶栗香的效果,单芽比一芽一叶制得的绿茶栗香品质更好。综合来看,电磁滚筒变温/热风耦合干燥技术作为一种有前景的加工技术,为栗香绿茶的加工提供一定的理论参考和技术支撑。
[Key word]
[Abstract]
In order to investigate the effect of electromagnetic cylinder variable temperature coupling hot air drying technology on the formation of chestnut-like aroma in green tea, the effects of different combinations of drum variable temperature , drying time, and coupling to hot air were investigated. The qualitative and quantitative analyses of aroma components were implemented by using infrared-assisted extraction coupled to headspace solid-phase microextraction (IRAE-HS-SPME) combined with gas chromatography-mass spectrometry (GC-MS), and the key compounds for chestnut-like fragrance were further screened by multivariate statistical analysis. The results showed that the best quality of chestnut-like aroma was obtained when the drying temperature of the electromagnetic drum was 180 ℃/170 ℃/160 ℃, coupling to hot air at 110 ℃ maintaining for 6 min. In addition, an effective discriminant model of green tea with chestnut-like aroma was established by partial least squares-discriminant analysis (PLS-DA) (R2Y=0.997, Q2=0.774). Based on VIP>1 and p≤0.05, 27 key differential compounds were screened out. Their distribution was further determined using hierarchical cluster analysis (HCA), and it was found that the contents of 27 volatiles were generally higher in chestnut-like aroma green teas than non-chestnut-like aroma green teas. In addition, the quality of chestnut-like aroma in green teas was influenced by the tenderness of the raw materials, too. Better quality of chestnut-like fragrance was obtained using green tea with a single bud than that with a bud and one leave. In general, as a promising processing technology, the electromagnetic cylinder variable temperature coupling to hot air drying technology provides theoretical reference and technical support for the processing of chestnut-like green tea.
[中图分类号]
[基金项目]
国家自然科学基金项目(31972465;31902083);中国农业科学院创新工程(CAAS-ASTIP-TRICAAS);浙江省自然科学基金项目(LQ18C160006)