Study On The Key Technologies For Brewing Haihongguo Brandy And Alcohol-free Beverage

Haihongguo is a unique fruit mainly growing in the northwest region of China and has a high nutrient and processing value. Because of the lack of storage technology and its preservation period is short, Haihongguo is mainly used to produce foods, such as preserved fruit, dried fruit, jam, drinks, Haihongguo wine and so on. At present, the production of Haihongguo brandy is blank yet. Producing Haihongguo brandy could not only make full use of the resources of Haihongguo, but also can increase the processing ways of Haihongguo and avoid the market risk. Therefore, it is very important to develop a process of Haihongguo brandy.The key technologies for brandy production which are also the main research contents in this study include:(1)Screening of specific yeast and optimization of its fermentation by response surface methodology for Haihongguo brandy.(2)Determination and optimization of distillation parameters such as the distilling temperature, alcohol content of distilled brandy, the amount of distilling brandy collected, and also the determination of intercept point of brandy during distillation.(3)Study on the factors affecting on aging of brandy with oak-sheets and optimization of aging conditions by orthogonal tests.(4)Study on the key techniques for the production of Haihongguo alcohol-free beverage, including the optimization of clarification process by response surface methodology, determination and optimization of deacidification process by ion exchange resins, and the determination of its deploying technique.The results showed that:(1) The optimal strain was VL2 for brewing Haihongguo brandy, the optimal fermentation conditions were the initial sugar concentration of 26°Brix, the fermentation temperature of 20℃ and the inoculation size of 0.23g/L. Under these conditions, the Haihongguo brandy was fruity, pure and the characteristic strong.(2) Distillation experiment results showed that electric heating was better in distillation. The optimal conditions were as follows: twice distillation were applied, for the first time, a rapid fire distillation at temperature of 90℃ was used without intercepting head and removing end-liquor. Under these conditions, the alcohol content of first distilled liquor was controlled to 28%(v/v). While for the second time, a slow fire distillation at temperature of 85℃ was reasonable and 1% head liquor was intercepted and 25% end-liquor was removed and the alcohol content of resultant brandy was controlled to about 68%(v/v). Under these conditions, the obtained Haihongguo brandy was pure and good taste.(3) The optimal aging conditions were the baked oak-sheet addition of 0.8%, the altermating temperature of aging between 50℃ and room temperature, ventilating for 1h every day. In these conditions, the aged brandy was golden in color, with fruit, wine and oak aroma harmony.(4) In Haihongguo alcohol-free beverage clarification, the results showed that the bentonite dosage of 5% and the chitosan dosage of 1% were better clarification methods. In addition, the optimal conditions for the compound clarification were determined to be the bentonite dosage of 1.06g/L, the chitosan dosage of 0.11g/L, the clarification temperature of 25℃, the clarification time of 16 h. Under these conditions,the clarified Haihongguo alcohol-free beverage had a transmittance of 95.1%, the tannin content of 5.98g/L, 3.82g/L less than that of unclarification Haihongguo alcohol-free beverage.(5) Deacidification test showed that A451 resin was the best decidification material. The optimal conditions of static adsorption were the used volume of alcohol-free beverage being 10 times more than the volume of A451 resin, static adsorption time of 4h. In the case, A451 resin achieved the exchange adsorption equilibrium, and the amount of apparent adsorption could reach to 2.48g/100 m L. Study on dynamic kinetics showed that the processing capacity and efficiency were better at flow rate of 4BV/h, the best processing capacity was reach to 8BV, and the acid content was decreased to 5g/L. The optimal conditions of alcohol-free beverage blending were determined to be the acid content of alcohol-free beverage of 5g/L, sugar content of 40g/L, and the addition of salt of 0.2g/L. In these conditions, the resultant Haihongguo alcohol-free beverage was sweet and sour taste.