LACTOPEROXIDASE EFFECTS ON RHEOLOGICAL PROPERTIES OF YOGURT

A mixed culture (Lactobacillus delbrueckii subsp. bulgaricus and Strep tococcus thermophilus) was inoculated into reconstituted skim milk and incubated. When 0.45 Unit/g or more of lactoperoxidase (LPO) was adde d, the yogurts had softer and smoother texture than untreated yogurt. The apparent viscosity of yogurt was also reduced by addition of LPO. The storage modulus (G') of the gel of LPO-treated yogurt decreased bu t the frequency-dependency remained unchanged. The amount of exopolysa ccharide or degree of proteolysis in yogurt was not changed by additio n of LPO.