Study On The Technology Of Black Tea Type Lactic Acid Bacteria Beverage Fermented By Summer And Autumn Tea Leaves

The summer and autumn tea leaves have been seriously wasted,and it becomes a focus on how to develop and utilize them.Using the juice of summer and autumn fresh leaves,a bio-drink was fermented by our own-isolated superior lactic acid bacteria,and its fermentation technology was optimized through single factor and orthogonal experiments.Its chemical and sensory qualities and hygienic qualities were analyzed,the proportion of its mixed products was proposed,and its antioxidant function were checked.The main results are showed as follows:1.The fermentation technology of black tea type lactic acid bacteria beverage fermented by summer and autumn tea leavesThrough single factor tests,it showed that the fresh tea leaves withering 4 h,withered leaves rolling 30 min and directly pulping as a propoption of 10 g rolled leaves added 100 ml water in a juice machine,and the sterilization of 110? with 10 min benefited to forming the quality of black tea type lactic acid bacteria beverage.Through the orthogonal test,the optimized fermentation technology was of the inoculum 10 mL/L,sugar concentration 60 g/L,fermentation temperature 28? and fermentation time 3-day.2.The dynamic law of quality formation of black tea type lactic acid bacteria beverage fermented by summer and autumn tea leavesDuring the 11-day fermentation,the change of its sensory quality was very significant,and the sensory score was 83.9;the fermented beverage was orange-red color,slightly turbid without precipition,fruit sweet and sour aroma with tea aroxna,and concentrated sour flavor with slight astringency but no bitterness.Compored to the 0-day fermentation,its main components had a very significant change(p<0.01);the soluble sugar,free amino acids,pH value,tea polyphenols,and flavonids decreased about 45.13%,91.38%,36.7%,27.44%and 37.84%,respectively;total acidity increased about 72.91%,and tea pigments reduced about different extents.3.Quality characterics of black tea type lactic acid bacteria beverage fermented by summer and autumn tea leavesThe unfermented black tea beverages had a dark red-brown color,a muddy form,and sweet incense of black tea,and no sour.The fermented black tea type lactic acid bacteria beverage had a tea and fruit sweet flavor,a bright orange-red color,and a sweet and sour taste without bitter taste.Compared with the unfermented beverage,the free amino acids,caffeine and thearubigins of the lactic acid bacteria beverage had little changes,but its tea polyphenols,flavonoids,theabrowns,soluble sugar and pH value reduced significantly,and its total acidity increased significantly.Compared with the unfermented beverage,tea catechins of the lactic acid bacteria beverage increased by 19.66%.The C did not change,but the others increased by different content,especially EGCG increased 84%.However,the GA decreased slightly.The type and component of aroma included aromatic compounds,alcohols,olefins,alkanes,aldehydes,ketones,acids,esters,phenols.Tea drinks and control are quite different about the type and content of aroma.There was a great difference in the type and content of the aroma components in lactic acid bacteria beverage when compared with the unfermented,and the largest components were acids in lactic acid bacteria beverage(about 1.07%),alcohols,alkanes and aromatic in the unfermented.4.Hygienic qualities of black tea type lactic acid bacteria beverage fermented by summer and autumn tea leavesThe contents of heavy metals and microbe index in black tea type lactic acid bacteria beverage both were lower than the relevant national standard of drinks.The number of total bacterial colony and coliform are<10 CFU/g and<30 MPN/100 g,respectively,and the pathogenic bacterium(Salmonella,Shigella,Staphylococcus aureus,Hemolytic streptococcus)were not detected out.5.The mixing technology of the flavor products using the black tea type lactic acid bacteria beverageFour flavor products were mixed and their best proportions were optimized.The mixing proportions were 3:100((honey to a fermented broth,v/v)of honey-type product,4:10(milk to a fermented broth,v/v)of milk-type product,1:4((banana juice to a fermented broth,v/v)of banana juice-type product and 5:1((water to a fermented broth,v/v)of original product.Because fruit juice-based drinks had a delicious and coordinated flavor with sweet and sou,its sensory score was higher than other flavor drinks.6.Antioxidant function of black tea type lactic acid bacteria beverage fermented by summer and autumn tea leavesThe rate of scavenging DPPH by black tea type lactic acid bacteria beverage fermented by summer and autumn tea leaves was up to 98.27%,and its IC50 was 47.56.The ability of scavenging O2-· by the fermented beverage was 500.05 g/L,and its IC50 was 11.82.The ability of scavenging OH· by the fermented beverage wa 186.99 g/L,and its IC50 was 22.51.The antioxidant functions of black tea type lactic acid bacteria beverage fermented by summer and autumn tea leaves was far lower than those of Vc,but slightly higher than those of the unfermented.