Study On Production And Clarification Of Beer Vinegar From Waste Beer

The waste beer is the by-product during the brewing process, accounting for approximately 1.5% of the total beer output。Nowadays, with the output of the beer increased,more and more waste beer is discharged, which has seriously polluted the environment. It is necessary to develop and explore the waste beer. In this paper,the waste beer is used as raw materia to produce vinegar, for the aim of comprehensive utilization of waste beer, which greatly cuts down the withdrawal of waste beer. We mainly investigate the effect of enzymolysis and heat treatment on the non-biological -stability of the the beer vinegar, the effect of mixed fermentation on the flavor of the beer vinegar and the effect of the clarifying agent on the beer vinegar.The beer vinegar is a kind of colloid system with abundant nutrition and complicated components. The back haze of beer vinegar is mainly because of excess of the HA protein and HA polyphenol. Its stability possesses some relativity. Many physical and chemical factors,such as, time, temperature fluctuation, illumination etc. can destroy the colloid balance in some extent, and the turdity appears. Although the turdity does no harm to people's health, appearance quality of the beer vinegar was greatly influenced. The paper selected the excellent clarifier via adopting different clarifier and the stability of the beer vinegar could be improved greatly.In order to clarify the beer vinegar , 3 steps as follow are carried through, the enzymolysis of the protein in the waste beer, the heat treatment and the clarification of the beer vinegar. The high molecular protein in the waste beer is decomposed into low molecular protein by the papayin, which not only prevent high molecular protein from turbidding,but also increase the content of amino nitrogen in the culture medium.In the heat treatment process with addition of carrageenan, the remanent high molecular protein flocculats and sediments, as a result, there is an appropriate content of high molecular protein in the waste beer.In the clarifying process of the beer vinegar, the study show that PVPP has the best effect on absorbent of polyphenols, mainly absorbing sensitive polyphenols and made the sensitive polyphenols the appropriate content in the beer. Lots of experiments show that three criteria for qualified beer vinegar is as follow, absorbance value≥95%, sensitive polyphenols≤80mg/L ,and not flocculatation and sedimentation in the protein atability experiment.The technology of the submerged fermentation has the advantages of short production period, slight environmental pollution and high yield of beer vinegar, but the taste of the vinegar is worse compared to that of the traditional solid-state fermentation. In the paper, the advantage and shortcoming of the two technology was analysised and compared, we find that the cause of the poor taste in the submerged fermentation is that there is only one fermented strains and only produce a few aroma subject. The mixed fermentation with aroma–produced yeast xjb45 and Acetibacteria AS1.41 was carried through, which increase the pathway of metabolism and kinds of enzymes. As a result, the clarifying and soft acid taste beer vinegar, with the malt flavouring and apple flavouring as main flavouring was produced.