Whey protein powder(protein content 35%)was used as fermentation substrate to prepare a beverage product with 1.0%protein.Firstly,the effects of protein powder addition,fermentation fat content,fermentation acidity and different proportions of fermentation strains on the stability were studied.With the centrifugal precipitation rate as the index,the optimal formula of fermentation base material was determined by orthogonal test.Stabilizers were selected by instability index,centrifugal sedimentation rate and stationary observation.Finally,the fermented whey beverage was prepared by fermenting materials,erythritol,concentrated monk fruit juice,citric acid and stabilizer,and the product formula was optimized by orthogonal test.The results showed that the optimal formula was whey protein powder 7.5%,strain 0.005%(ratio of Streptococcus thermophilus and Lactobacillus plantarum 1∶2),fermentation acidity 35°T.The formula of the product was as follows:fermentation base material 40%,erythritol 6%,concentrated monk fruit juice 0.2%,citric acid 0.2%and propylene glycol alginate 0.4%.The product was milky white,sweet and sour,rich in fermentation aroma,and the comprehensive score was 87.The results are expected to be helpful for the development of whey fermented beverages or the reuse of whey in the cheese industry.
whey proteinfermented wheycentrifugal sedimentation rateinstability index