A Study On The Microbial Safety Of Non-pasteurization On IPA Beer

In this paper,the experiment uses a linear relationship between the content of tetrahydroiso-alpha-acid and the bitterness it imparts to beer,adding different concentrations of tetrahydroiso-alpha-acid to the culture medium of different beer harmful bacteria.To measure the bitterness value of the beer and to determine the degree of bitterness reached,which can inhibit their growth and reproduction.According to the obtained bitterness value,the stability of the beer in the case of non-pasteurization was tested and evaluated for the IPA beer under the bitterness value.The experimental results show that when the added hop content makes the bitterness value of IPA beer reach 50~80IBU,the antibacterial effect is the best.It's not only prolong the storage time of the beer with the non-pasteurization conditions,but also maintain the flavor.At the same time,the experiment also analyzed and compared the turbidity values of different bitter non-bacterial IPA beer at different periods to find out the correlation between the enhanced test and the actual shelf life of IPA beer.Predict the shelf life of the finished beer in a relatively short period of time,in order to measure the stability of IPA beer with different bitterness value,it is more accurate to assess the actual shelf life of the product.During the production process of beer and the preservation process of beer after filling,the flavor substances of beer constantly change due to various reasons,such as the color of beer will gradually deepen,the hop aroma of IPA will fade,and even disappear quickly.The bitterness will gradually decrease,and the oxidation of aldehydes and phenols in beer will cause some bad flavors such as cardboard taste and light odor.By measuring the TBA value and DPPH clearance rate of non-pasteurized IPA beer with different bitterness values at different times,the lower the TBA value of the finished beer,the more pure the flavor of the beer and the more stable the flavor.The pasteurization process accelerates the aging and oxidation of the beer,and the aging substances in the beer are significantly increased.At the same time,the heating destroys the original anti-aging substances in the beer,such as the original polyphenols in the beer.During the later period of beer storage,the stability of the pasteurized IPA beer was more stable than that of the non-pasteurized IPA beer.The aged oxidation of the pasteurized IPA beer during the initial storage period was higher than that of the bared IPA beer,but due to the early period The high-temperature heating causes theaging substances in the beer,such as some macromolecules,to reduce the phenols and aldehydes.On the contrary,the heating increases the aged substances in the beer,thereby making the pasteurized IPA beer more aging than the non-pasteurized beer.