Effect of Ultra High Pressure Treatment on γ-Aminobutyric Acid and Volatile Components in Germinated Brown Rice Wine

The germinated brown rice was used as raw material to brew brown rice wine. The germination temperature,germination time,ultra-high pressure treatment pressure and ultra-high pressure treatment time were optimized by single factors. The contents of γ-aminobutyric acid(GABA)in wine was investigated under different conditions. The volatile components in the germinated brown rice wine were detected by headspace solid phase microextraction(HS-SPME)combined with gas chromatography-mass spectrometry(GC/MS). The results showed that the germination condition was 28℃ for 20 h,and the obtained germinated brown rice had a high GABA contents of 346.7 μg/g. The GABA contents of the germinated brown rice wine was 24.7 mg/L. At the ultra-high pressure treatment pressure of 200 MPa and the ultra-high pressure treatment time of 30 min,the GABA contents of the finished brown rice wine was higher,reached 27.4 mg/L. In the germinated brown rice wine treated with 200 MPa,12 kinds of alcohols,20 kinds of esters,5 kinds of ketones and 1 kind of acid were detected. Compared with non-pressurized germinated brown rice wine,the types of esters in the germinated brown rice wine after ultra-high pressure treatment increased,the alcohol contents decreased,and the acid contents decreased. Through sensory evaluation,it was found that samples treated at 200 and 300 MPa were superior to the untreated group,which indicated that the pressure treatment improved the taste of the germinated brown rice wine and greatly improved the flavor quality of the rice wine.