超高压处理对发芽糙米酒中γ-氨基丁酸及挥发性成分的影响
Effect of Ultra High Pressure Treatment on γ-Aminobutyric Acid and Volatile Components in Germinated Brown Rice Wine
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摘要: 以发芽糙米为原料酿造米酒,对发芽温度、发芽时间、超高压处理压力、超高压处理时间进行单因素实验,考察不同条件下酒中γ-氨基丁酸(γ-aminobutyric acid,GABA)含量,并对米酒成品采用顶空固相微萃取(HS-SPME)结合气相色谱质谱联用(GC/MS)技术检测发芽糙米酒中的挥发性成分。结果显示,发芽条件为温度28℃、时间20 h,获得的发芽糙米GABA含量较高,为346.7 μg/g。发酵后获得的发芽糙米酒GABA含量为24.7 mg/L。在超高压处理压力200 MPa、超高压处理时间30 min,获得的糙米酒成品GABA含量较高,达到27.4 mg/L。在200 MPa处理后的发芽糙米酒中共检测出醇类12种,酯类20种,酮类5种,酸类1种。相较于未经超高压处理的发芽糙米酒,超高压处理后的发芽糙米酒中酯类种类增加,醇类含量减少,酸类含量减少。通过感官评价,发现200和300 MPa处理的样品均优于未处理组,说明加压处理提高了发芽糙米酒的滋味,大大提高了米酒的风味品质。Abstract: 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.