Research On Technology Of Walnut Lactobacillus Fermentation Drinks

The traditional lactobacillus fermentation drinks are generally based on milk as a raw material. Plant protein resources are more abundant than animal proteins such as milk in China, and have a complementary role in the amino acid composition. It is important to develop plant protein processing and utilization in China for solving the lack of milk resources and improving diet structure.The purpose of this study was to use walnut residue as high quality plant protein resources, combined with the advantages of lactic acid bacteria fermentation, comprehensively considering the physical and chemical index, microbiology index and sensory quality of the products, to obtain the optimal processing conditions and formula for the preparation of walnut lactobacillus fermentation drinks. The main results were as follows:1. Preparation of raw fermentation solution of walnut: The walnut residue was dipped into95℃hot water for4min before beating, to protect the color effectively. When beating the walnut residue in80℃, the walnut protein dissolution rate was the highest. A solid-liquid ratio of1:10could contribute to the best sensory quality.2. Domestication of strains:strains were domesticated by choosing the gradual domestication method. After the raw walnut solution were fermented by domesticated strains, the acidity reached up to69°T, increased by50percent than before and the viable count reached up to2.9×10’/mL, an increase of about17times more than before. Sensory quality was also improved significantly.3. Stability research:Considering the centrifugal sedimentation rate and the sensory quality as the inspection object, the optimal sterilization condition was sterilization temperature of65℃and sterilization time of25min. Compared with the CMC-Na and AGAR, sucrose ester had positive influence on the stability and the suitable adding amount was0.3%.4. Fermentation process research: Based on the orthogonal experiment the optimal fermentation process condition was at an inoculated quantity of3%, fermentation temperature of37℃fermentation time of10h, and sucrose adding amount of5%.5. Antioxidant activity research:walnut lactobacillus fermentation drinks (C=0.988g/mL) from the optimal technology had obvious antioxidant activities. The DPPH· scavenging rate, OH· scavenging rate and total antioxidant ability were respectively equivalent to those of0.463mg/mL,5.4mg/mL and0.212mg/mL ascorbic acid solution.