Research On Production Process Of Beer Using OAT Malt As Ingredients

Oats, as our abundant grain resources, has been widely applied in the production of healthy food, beverage, cosmetics and so on. The use of oat malt can not only enrich the types of beer, but also can improve the oats nutritional value. The influence of production process on the quality of oat beer was investigated by single factor, orthogonal experiments and response surface methodology. Furthermore, we found the best clarification and the amount of clarifying agent of oat beer.The main conclusions of this study are as follows:(1) The overall optimum saccharification conditions were established as follows, the proportion of oat malt was 50%, the ratio of raw materials to liquid was 1:4, and protein inactivity time Ⅱ and saccharification time for the first stage were 50 min and 90 min respectively.(2) The oat malt proportion, the ratio of raw materials to liquid and protein inactivity timeⅡ were the main factors affecting the oat malt wort. The result shows that reducing sugar content of the first wort is not substantially affected by saccharification time when above 60 min.(3) The effects of the key parameters including fermentation time, fermentation temperature and yeast addition level on the oat beer’s alcohol content and diacetyl content were investigated. The optimal levels for fermentation were obtained, including fermentation time of 8d, fermentation temperature of 13.51℃, yeast addition level of 0.45%. Under optimized conditions, the oat beer’s alcohol content was 4.21 %(v/v) and diacetyl content was 0.28mg/L.(4) Compared with the normal clarifying agent, it is concluded that tannin and PVPP have a better clarification effect on protein and polyphenol, which leads to a higher beer clarification of 88.7% and beer colority of 25.33 EBC. Compared with commercial beer, the oat beer not only has a higher alcohol, polyphenol and protein content, but also has a darker color.