Study On The Brewing Technology Of Alcohol-free Cider

Cider is a kind of fruit wine which refers to the fresh apple juice or apple juice concentrate as raw material, adding suitable yeast and fermentation under certain condition of a period of time to complete. Cider is rich in nutrients, and has a variety of health functions, such as regulation of organism’s, anti-aging, beauty care, and so on. Cider containing alcohol limits the number of people and occasions of drinking. Therefore, low alcohol and non-alcoholic cider are extremely popular with consumers. Selecting suitable apple variety, alcohol-removal method and maximizing the retention of cider nutrients, volatile aroma compounds is the focus of the present study.In this study, we used different apple varieties as raw material. The aroma components of different apple varieties were measured by GC-MS respectively. The principal component analysis(PCA) and cluster analysis(CA) were used to select apple varieties with the aroma components similar to that of special apple variety. Then the mixture of some varieties which has most similar aroma components with the special apple variety were used as materials to ferment cider and strain was selected as fermentation starter. The cider’s alcohol degree was reduced by adding glucose oxidase in apple juice. Using the single factor experiment and response surface optimization test to determine the optimal fermentation technology. At last,the alcohol in fermented product was removed by Reverse Osmosis. Main results for this study are as follows:(1) Ten kinds of domestic apple cultivars and US special apple dedicated to the apple wine as raw material. The aroma components of these samples were determined by GC-MS. The PCA and CA were used to analyse the aromatic components and content differences among apple varieties. Then the mixture of four varieties which has similar aroma components with the special apple variety was selected and used for fermentation. The hybrid contained Fuji,Pink Lady, Golden Delicious and Red Star. This study provided an effective method to select appropriate apple varieties for cider fermentation.(2)The best technology conditions for using glucose oxidase to product low-alcohol cider were as follows: the fermentation temperature 22.90℃, the pH of apple juice 4.65 and the addition amount of glucose oxidase 2.84 mg. Under these conditions, the cider alcohol degree6.35%(V / V), 2.9% lower compared to the control group.(3) Film properties and technological research on two kinds of reverse osmosis membranes and one nanofiltration membrane and GC-MS analysis of samples brought the results that: The most suitable membrane for cider dealcoholization is Al RO98 pHt reverse osmosis membrane. RO98 pHt membrane performance was stabilized after running 40 min.The concentration factor of 0.7 was the best adding water time. When pressure was 1.6 MPa,Ethanol can be removed better and the loss of the extract in cider decreased.