Study On The Fermentation Characteristics And Quality Of The ?-amino Butyric Acid Yoghurt

In this paper,the effects of Lactobacillus caseiwith high yield of ?-aminobutyric acid and,banana juice with high activity glutamate decarboxylase on the fermentation process and of yogurt were studied.The the quality characteristics comparation off our kinds of commercially-available yogurt and ?-aminobutyric acid yogurt were also investigated.The results were as follow.(1)In fluence of the Lactobacillus casei addition onthequality and fermentation of yogurt.Experimental data result edthatthe internal structure of fermented yogurt was good when the addition amount of 2% of lactobacillus casei,and the hardness,viscosity,cohesiveness,elasticity,water-holding capacity reached the maximum.The yield of?-aminobutyric acid are increasing along with the lactobacillus casei addtion.When the fermentation temperature is 40 ?,which is most suitable for the lactobacillus casei growth,hardness,cohesiveness,elasticity,water of yogurt are ecreasing with the fermentation.As temperature rised,the viscosity showed a declinetrend.The yield of?-aminobutyric acid increased and then decreased,along with the fermentation temperature increased,and at 40?the ?-aminobutyric acid yield reaches maximum.(2)Influence of the addition of banana extract on the fermentation process and the quality of the product.The additions of banana extract were beneficial tothelactic acid bacteria growth.The addition oftheheat treated banana extract,lactobacillus caseiin fermentation process growed faster than that of the untreated banana extract.The addition of banana juice affected the texture characteristics of yogurt.With the increase of the addition of banana extract,the hardness,viscosity and elasticity of yoghurt are increased first and then decreased,and the cohesion is increased and then decreased.The yield of?-aminobutyric acid in yoghurt increased significantly when addedthe banana juice,and the effect of the untreated banana juice is much greater than that of the heat treated banana.(3)Comparision of the ?-aminobutyric acid yogurt with four kinds of commercially available yogurt.The results showed that the five kinds of yogurt were glossy,smooth,delicate taste,smooth,evenly organized,and the number of viable cells,acidity,protein reached the national standard andhad little difference,Mengniu have the highest protein content,which taste sweet.Five kinds of yogurt elasticity has littledifference,hardness and viscosity of Kang Xiaole is relatively large.?-aminobutyric acid yogurt by adding Lactobacillus casei and banana juice extract not only had special banana flavor,but also the GABA content were significantly higher than the commercial yogurt.