干燥方式对秋葵花茶及其茶汤风味的影响

Effect of drying method on the flavor of okra flower tea and its soup

采用气相色谱高通量飞行时间质谱仪(GC-TOFMS)对两种不同干燥方式(冷冻干燥和热风干燥)制备的秋葵花茶及其茶汤中挥发性成分进行检测、分析。结果表明:两种干燥方式制备的秋葵花茶及其茶汤中的挥发性化合物共194种,并以有机酸类、糖类和氨基酸类为主;冷冻干燥花茶茶汤中糖类、有机酸类、醇类、酰胺类、酯类、磺酸类、苷类的相对含量高于热风干燥的;其中,冷冻干燥花茶茶汤中的糖类、有机酸类、氨基酸类和醇类的相对含量分别为27.342,14.025,18.553,7.157,而热风干燥的分别为17.701,8.774,2.517,4.610;冷冻干燥花茶茶汤中的热敏成分——总酚、总黄酮及维生素C的相对含量高于热风干燥的,其中总酚含量存在显著差(P<0.05);热风干燥花茶茶汤中的风味物质——糖醇类、糖酸类、糖胺类、羟胺类、含磷化合物、杂环类的相对含量高于冷冻干燥的。综上,冷冻干燥有利于保留秋葵鲜花中原有的组分及生物活性物质,热风干燥有利于秋葵花茶及其茶汤中风味物质的形成。

The volatile components of okra flower tea and its soup prepared using different drying methods were tested and analyzed by high throughput time of flight mass spectrometry(GC-TOF-MS),and the components of okra flower tea and its soup were determined.The results showed that 194 volatile compounds were identified in okra flower tea and its soup prepared by using the two drying methods.Among them,organic acids,sugars and amino acids were the main ones.The relative contents of sugars,organic acids,alcohols,amides,esters,sulfonic acids and glycosides in freeze-dried flower tea and its soup were higher than those in hot-air dried flower tea and its soup.Among them,the relative content of carbohydrates,organic acids,amino acids and alcohols in freeze-dried flower tea soup was 27.342,14.025,18.553 and 7.157,respectively,while that of carbohydrates,organic acids,amino acids and alcohols in hot-air dried flower tea soup was 17.701,8.774,2.517 and 4.610 respectively.In addition,the relative contents of total phenol,total flavone and V C in freeze-dried flower tea soup were higher than those in hot-air dried flower tea soup.Among them,the content of total phenol was significantly different(P<0.05).However,the relative contents of glycoalcohols,glycoacids,glycoamines,hydroxyla-mines,phosphorus compounds and heterocycles in the hot-air dried flower tea soup were higher than those in the freeze-dried flower tea soup.To sum up,the freeze-drying method was conducive to retain the original ingredients and bioactive substances in okra flowers,while hot-air drying was conducive to the flavor substances formation of okra flower tea and its soup.