干燥方式对苦瓜茶感官品质及挥发性物质的影响

Effect of Drying Methods on the Sensory Characteristics and Volatile Compounds of Momordica charantia Tea

目的:研究不同干燥方式对苦瓜茶感官品质、色泽、水浸出速率和浸出物含量以及主要挥发性物质的种类及含量的影响,为筛选苦瓜茶适宜加工方式提供理论依据。方法:以感官评分、色差值、水浸出速率和浸出物含量为评价指标,通过固相微萃取和气相色谱-质谱联用(SPME/GC/MS)方法对苦瓜茶的挥发性成分进行定性和定量检测,比较真空冷冻干燥、日晒干燥、热泵干燥、热风干燥、微波干燥和真空干燥共6种干燥方式对苦瓜茶感官品质及挥发性物质的影响。结果:各干燥方式的苦瓜茶感官评分从高到低依次为热风、微波、真空、真空冷冻、日晒和热泵干燥。真空冷冻干燥苦瓜茶水浸出速率最快,浸出物含量最低。真空干燥浸出速率慢,浸出物含量高。从6种干燥方式的苦瓜茶挥发性物质中共检出119种,其中共同检出3种,分别为2-己烯醛、(E,E)-2,4-庚二烯醛、苯乙醛,是苦瓜茶的主要挥发性物质。真空冷冻干燥苦瓜茶挥发性物质种类最多,热泵干燥最少。真空干燥挥发性物质的种类和组成含量与其它方式相比有较大差异。热风、日晒和微波干燥挥发性物质组成较为相似。结论:干燥方式对苦瓜茶感官品质及挥发性物质种类及含量影响较大。综合比较后热风干燥苦瓜茶感官品质最佳。

Objective: The objective of this study is to provide theoretical basis for choose the optimal industrial production mode of the drying process of Momordica charantia L. tea by studying the effect of different drying methods on sensory evaluation, color, water leaching speed, water solubility index, and the kinds and content of volatile compounds.Method: Sensory evaluation, color, water leaching speed and water solubility index were taken as evaluation indices.Moreover, the species and content of volatile compounds of Momordica charantia tea was analyzed by SPME/GC/MS. Vacuum freeze drying(VFD), sun drying(SD), heat pump drying(HPD), heat air drying(HAD), microwave drying(MD)and vacuum drying(VD) were adopted to dry Momordica charantia tea, and then the effects of six drying methods on sensory characteristics and volatile compounds during processing were studied. Result: The sensory evaluation of Momordica charantia tea by different drying methods from high to low in order was HAD, MD, VD, VFD, SD, HP. VFD had the fastest water leaching speed but the lowest water solubility index. VD had the slow water leaching speed but the highest water solubility index. There were 119 kinds of volatile compounds from six drying methods. Among them, 2-hexenal,(E, E)-2, 4-heptadienal and phenylacetaldehyde were tested in every method. The 3 kinds compounds were the main volatile compounds of Momordica charantia tea. VFD had the most kinds volatile compounds, but the least in HPD.The kinds and content of volatile compounds were different between VD and other methods. While, HAD, SD and MD had the similar constitute of volatile compounds. Conclusion: The results indicated that there are significant differences in sensory characteristics and volatile compounds of Momordica charantia tea among different drying methods. Momordica charantia tea dried by HAD had the best sensory quality.