Abstract: Milk is rich in active nutrients,including lactoferrin,immunoglobulin,lactoperoxidase,α- Lactalbumin,β- Lactoglobulin,and so on. After high temperature sterilization,the active nutrients of yogurt produced by traditional technology are almost completely lost. In this experiment,a new yogurt production process was used to produce high active nutritional yogurt. Firstly,the milk fat was separated,the milk fat part was pasteurized at 125 ℃ for 5 s,and the skim milk part was pasteurized at 75 ℃ for 15 s. After the mixture of the two parts,the Lactobacillus bulgaricus and Streptococcus lactis were added to ferment to the acidity of 75~85° T,and then cooled and postripenessd for more than 8 hours. After determination,the contents of α-lactalbumin,β-lactoglobulin,lactoferrin,immunoglobulin,and lactoperoxidase in the new craft yogurt are 966 mg/L,1 963mg/L,23.4 mg/L,102 mg/L,1 025 U/L,respectively,which were much higher than 68 mg/L,200 mg/L,0.7 mg/L,14 mg/L and 0 U/L of traditional yogurt. There was no significant difference in the number of viable bacteria,viscosity,acidity and taste between the new process and the traditional process yoghurts during their shelf life.

Key words: high quality yoghurt, active protein, β-Lactoglobulin, immunoglobulin, lactoferrin