Development Of Blueberry Beer And The Study On Its Stability

Beer is a kind of low-alcohol drink,known as liquid bread,with the biggest production and sales in liquor.In 2014,the output of beer in China was close to 50 million tons,and China has been the country with the biggest beer production and consumption in the world for 14 years.At present,beer products in China have still been dominated by pale beer with single variety.With the continuous improvement of people’s living standards and the deepening of healthy drinking concept,the demand for new varieties of nutritious and functional beer will increase.Blueberry is a new small bluish-black berry.In recent years,a large number of studies have shown that the blueberry fruit contains abundant active substances of phenols such as anthocyanins and flavonoids,in addition to rich sugars,acids and aromatic ingredients,having a variety of physiological functions on human body.Thus blueberry is a kind of healthy food.In this paper,we use blueberry,malt and hops as the main raw materials to explore the brewing condition and stability plan of new blueberry fruit beer.By studying the effects on the quality,flavor and colloid stability of this beer due to different juice adding methods and different raw material ratios,we optimize the raw material ratio of blueberry beer,revealing the change of phenolic compounds in the storage process of blueberry fruit beer,the 1,1-diphenyl-2-trinitrophenylhydrazine(DPPH)free radical scavenging rate and the change rule of thiobarbituric acid(TBA)value reflecting the degree of beer aging.The main results are as follows:1.The study on the effect of different adding methods of blueberry juice on fruit beer quality.By adding blueberry juice respectively in the stages of main fermentation,after fermentation and beer storage,with sensory evaluation and flavor stability research,we get the results that adding blueberry juice in the stage of main fermentation can make blueberry beer quality better.2.The study on the effect of different raw material ratio on fruit beer quality.The results show that increasing the adding of blueberry juice and hops can effectively improve the beer flavor stability,while increasing the original wort concentration will not conducive to the beer flavor stability.When the blueberry juice addition is 12%,the original wort concentration 10°P and the hop addition 2g/L,the appearance of fruit beer becomes clear and bright,with a pure color and unique fragrance of blueberry and beer,combining with beer flavor.The two kinds of aroma become harmonious,with a mellowtaste and strong stability,thus we achieve a unique fruit-brew beer by this way.3.The study on the aroma components of blueberry fruit beer.We use the solid phase microextraction(HS-SPME)coupling with the gas chromatograph mass spectrometry(GC-MS)to detect and analyze the aroma components.The result shows that blueberry fruit beer contains 22 kinds of aroma components,of which ester compounds are 11,alcohol compounds 6,acid compounds 3,and phenolic compounds 2.Compared with common beer,the fruit beer has higher content with four more species in aroma substances,which indicates that adding blueberry juice during fermentation can enrich the substances for beer flavor.4.The study on the stability in the storage process of blueberry juice beer.The results show that the total phenolic content and DPPH free radical scavenging rate in blueberry fruit beer show a declining trend in the storage process,especially in the early stage of storage,while the TBA value in the storage process keeps increasing with time.In the storage process,the total phenolic content is positively correlated with DPPH free radical scavenging rate,but negatively correlated with the TBA value,with a more significant correlation in the early storage process.In comparison with common beer,the blueberry fruit beer has stronger flavor,biological and colloidal stability.