Effect Of New Hops Extract On Beer Related Microorganisms

At present,there are few studies on hops extract in China,and there are fewer studies on isomerized hops extract,so this experiment studies the specific inhibition effect of isomeric hops extract by using dihydro,tetrahydro and hexahydrogen isomeric hop extracts to inhibit beer-related microorganisms and their effects and related strains on beer quality.Firstly,by two experiments of the specific growth rate and the change of colony morphology were carried out to study the inhibitory effect of the isomerized hops extract by different processes on the related microorganisms in beer.The results showed that Staphylococcus aureus had the most inhibitory effect under the same concentration gradient of isomerized hops extract,indicating that it was more sensitive to hop extract,and at the concentration of isomeric hop extract of 0.04 g/L,the specific growth rate of Staphylococcus aureus decreased rapidly,then remained unchanged,and was completely inhibited at 0.5g/L.The specific growth rate of Lactococcus was exponentially distributed with the concentration of isomerized hops extract.When the concentration of isomerized hops extract reached 5g/L,Lactococcus without colony growth,at the same time,the strain of Lactobacillus brevis did not grow at this concentration.The specific growth rate of Escherichia coli was basically inversely proportional to the concentration of isomerized hops extract,when the concentration of isomerized hops extract was 3g/L,Escherichia coli could be completely inhibited.When the concentration of isomerized hops extract was 4g/L,wild yeast did not appear colony growth,that is growth was completely inhibited.The growth of Saccharomyces cerevisiae DM303 did not change significantly,indicating that it was less affected by the isomerized hops extract.The above results showed that the different isomerized hops extract had different inhibitory effects on different kinds of beer harmful bacteria,but the general trend was similar.Through the experimental study of different isomerized hops extract,it was found that the hexahydrogen isomeric hop extracts had the best inhibitory effect on the related microorganisms in beer,the inhibition effect of tetrahydroisomeric hop extract belonged to the middle state,and the hexahydroisomeric hop extract had the worst inhibition effect.In the experimental results of different hop extracts and related strains on beer quality,it can be found that the color,turbidity,and residual sugar of the brewing beer of the isomerized hops extract basically did not change,and the harmful bacteriaadded were stopped by the inhibition of hop,the aroma and bitterness value of beer samples added with isomerized hops extract were better than those of beer added with hop pellets.Therefore,the study shows that the addition of isomerized hops extract will not damage the physical and chemical indexes of beer,and will not reduce the overall quality of beer,it provides a theoretical basis and guarantee for isomerized hops extract to replace hop pellets in actual beer brewing.