关键词: 软儿梨, 果酒, 挥发性风味物质, 动态变化, 气相色谱?质谱联用

Abstract:

Ruan'er pear is a unique "frozen fruit" product in Northwest China. It is sour， sweet and delicious with rich fruit aroma. It is the best raw material for brewing fruit wine. In order to clarify the retention of fruit aroma in the fermentation process of fruit wine， and to explore the effect of fermentation time on the quality of Ruan'er pear wine， the frozen fruit of Ruan'er pear in Minhe County of Qinghai Province was used as raw material. Based on the fermentation process with skin residue， the volatile flavor compounds in raw juice （0 d）， pre fermentation （7， 14， 28 d） and post fermentation （100 d） samples were analyzed by headspace solid?phase microextraction?gas chromatography?mass spectrometry （HS?SPME?GC?MS）. Effects of original fruit flavor retention and post fermentation time on flavor of Ruan'er pear wine were discussed by relative odor activity value （ROAV） and principal component analysis （PCA）. The results showed that： a total of 88 volatile compounds were detected in the whole fermentation process， including 33 esters， 29 alcohols， 6 acids， 7 terpenes and 13 other compounds， and the total content of flavor compounds increased first and then decreased slightly with the fermentation process. The results of ROAV showed that there were 8 kinds of key flavor compounds in original fruit of Ruan'er pear， which were ethyl butyrate， ethyl hexanoate， ethyl 2?methylbutyrate， n?octanol， damascone， linalool， eugenol and decanal； among them， ethyl caproate， n?octanol， linalool， eugenol and damascone were well preserved in fruit wine， which were the key substances to determine the flavor of Ruan'er pear wine. Principal component analysis showed that the main aroma contributing substances in the early stage of fermentation were ethyl butyrate， 3?hydroxyethyl butyrate and 2?methylethyl butyrate. When fermented to 100 d， ethyl acetate， ɑ?terpineol， limonene and linalool contributed a lot to the aroma. These aroma compounds together gave Ruan'er pear wine unique flavor quality of delicate fragrance and rich fragrance. In this study， the key flavor compounds of Ruan'er pear wine and the change rules of characteristic flavor compounds in different fermentation stages were obtained， which can provide theoretical support and reference for the development of high?quality Ruan'er pear wine products and the improvement of Ruan'er pear wine fermentation process.

Key words: Ruan'er pear, fruit wine, volatile flavor compounds, dynamic change, gas chromatography?mass spectrometry