关键词: 糙米酒酿, 工艺优化, 风味, 气相色谱-嗅闻-质谱, 偏最小二乘回归分析法

Abstract: The preparation of sweet rice wine from brown rice was optimized using single factor and orthogonal array design methods for higher comprehensive sensory evaluation scores as calculated by fuzzy mathematics. Headspace solid phase microextraction (HS-SPME) coupled with gas chromatography-olfactometry-mass spectrometry (GC-O-MS) and partial least squares regression (PLSR) were used to compare the flavor characteristics of brown rice wine with those of glutinous rice wine, and the correlation between flavor components and sensory attributes of brown rice wine was explored. The results showed that the optimum preparation conditions were determined as follows: soaking time of brown rice 8 h, cooking time 35 min, adding 0.4% koji, and fermentation at 35 ℃ for 60 h. A total of 47 flavor substances were identified in the brown rice wine prepared under the optimized conditions; 29 of these could be smelled and recognized. At a split ratio of 27, ethanol, ethyl butyrate, 2-pentylfuran, methylheptenone, hexanol, and mushroom alcohol could still be sniffed and recognized as the main aroma of brown rice wine. PLSR analysis showed that the flavor components such as ethanol and ethyl butyrate had a strongly positive correlation with the winy, fruity and floral aroma of the rice wine, while 2-pentylfuran, methylheptenone, hexanol, and mushroom alcohol had a strong correlation with the rice aroma. These results provide a theoretical basis for the preparation and flavor evaluation of brown rice wine with unique flavor.

Key words: brown rice wine, process optimization, aroma, gas chromatography-olfactometry-mass spectrometry, partial least squares regression analysis