The Development Of The New Technology Of Liquefaction For Chinese Rice Wine Brewing

Rice steeping and steaming in the process of conventional Chinese rice wine brewing discharge a large amount of wastewater and consume much energy, especially it is difficult to deal with the wastewater, which is a headache in many rice wine factories. The liquefaction for Chinese rice wine brewing is a new technology, which is using the amylase to liquefy rice particles instead of rice steeping and steaming. The new technology has the advantage of energy-saving and emission-reduction, convenient for the mechanized delivery and cleaner production. The research on the liquefaction for Chinese rice wine brewing most remain in the lab, the industrial production has not been formed so far. Our main work cared about the whole process of liquefaction for Chinese rice wine brewing, then scale-up test would be carried out in the factory. The feasibility of producing Chinese rice wine with liquefaction would be evaluated, which would lay the foundation for the other new technology of Chinese rice wine.Two important parts were studied in this paper, including control of the extent of liquefaction and the usage of wheat qu. The proper extent of liquefaction was that partial long-chain starch became dextrin and oligosaccharides, in order to make sure of the role of wheat qu during fermentation, and characteristics and quality of Chinese rice wine. Rice grinding degree, addition of thermostableα-amylase and liquefaction time, which affected extent of liquefaction and brewing, were studied. The addition of thermostableα-amylase was the most important factor, secondly liquefaction time, rice grinding degree was least. Through the Orthogonal experiment, the applicable extent of liquefaction was determined and the proper conditions of liquefaction was rice grinding to 27 mesh number, adding 5U/g thermostableα-amylase, liquefying 6 mins under 100℃. Through the analysis of sugar molecular chromatography of liquefied mash by HPLC, the liquefied conditions was proper.Wheat qu still played an important role in the new technology of liquefaction for Chinese rice wine brewing. Because of the liquefying of amylase ahead of time, wheat qu could be reduced moderately, and the Chinese rice wine would become much fresher with less wheat qu. Through the analysis of the synergism between wheat qu and enzyme, it was found that saccharifying power of wheat qu was not enough, so appropriate amount of glucoamylase (10U/g) should be supplemented. Wheat qu affected on the whole process of brewing, including fermentation rate and quality of wine, especially the content of amino acids and flavor. By the sensory evaluation and analysis of volatile compound in rice wine, the Chinese rice wine with 7% wheat qu was the best.The scale-up tests in lab and factory proved that produce of Chinese rice wine with the new technology of liquefaction was feasible in the factory. The Chinese rice wine with new technology has its own characteristic, which has light aroma and refreshing taste. Through the analysis of amino acids and volatile compounds in wine, the Chinese rice wine with the new technology of liquefaction is different from traditional one, belonging to the light aroma style ones. It has its own feature, so it will be promising for market in the future. Contrast with the conventional technology, the new technology could save more than 25% energy per ton of rice, and almost none wastewater would be discharged.