Processing Of Fermented Beverage On Apricot Juice And Its Volatile Compounds

The change was studied on total sugar, titratable acid, alcohol content and sensory quality of apricot (cv.Lanzhoudajie) juice fermented in the different conditions. The optimum parameters of clarification were carried out in this paper. The volatile compounds of apricot juice and its fermented juice were isolated and identified with SPME (solid-phase microextraction) and gas chromatography-mass spectrum (GC/MS). The results showed that the optimum parameters of fermentation with single yeast were 25℃for 12h, pH3.5, 3% of inoculum amount and dried active yeast powder as fermentation microorganism. The optimum parameters of fermentation with two yeast strains were 25℃for 20h, pH3.5, 3% of the inoculum amount and 1:3 ratio of dried active yeast power and fruit wine yeast.The flavor of apricot juice fermented with two yeast strains was intense and full compared with the single strain yeast fermentation. The optimum parameter of clarification was 0.1% of 1% pectase for 40min at 45℃. The rate of fermentation increased as long with the increase of fermentation temperature and the content of residual sugar was higher and the alcohol content was lower after fermentation. The titratable acid increased firstly, then decreased in the different condition of fermentation temperature. The higher fermentation temperature, the faster change of titratable acid content, while the value of variation was low. The titratable acid in fermented apricot juice was higher than in apricot juice. The higher alcohol? increased; however, the esters and lactones decreased with the increase of fermentation temperature. Terpineol was higher at 25℃of fermentation temperature than that at both 20℃and 30℃. The pH had no effect on the fermentation rate, titratable acid and alcohol content under the same temperature. The higher alcohol reduced by 40.5% at pH3.5; however, esters, lactones and terpineols increased by 55.1%, 58.8% and 12.9%, respectively, compared with that at pH 4.0. The higher ratio of fruit wine yeast, the lower of fermentation rate and alcohol content. The titratable acid increased for 16 h in the condition of single yeast, while it increased for 20h in the other condition of yeasts. The fruit wine yeast produced more flavor volatiles than dried active yeast power. The ratio of yeasts affected on the kinds of volatile compound; however, no effect was observed on the relative content ..