YOGURT PRODUCTION FROM RECONSTITUTED SKIM MILK POWDERS USING DIFFERENT POLYMER AND NON-POLYMER FORMING STARTER CULTURES

Using polymer producing (ropy) strains of lactic acid bacteria it was possible to reduce considerably the syneresis of yogurt, even with 12% total milk solids. The viscosities obtained with these strains were a lso similar to those obtained using normal strains and milk with 17% t otal solids content. The concentration of milk and the polymer produce d by ropy starters had a synergic effect in increasing viscosity. Poly mer production was not affected in most cases by milk concentration. O ne type of ropy culture (Wiesby) seemed to produce a different kind of polymer as it could not be determined by alcohol precipitation, in sp ite of being able to reduce syneresis and increase viscosity in yogurt . A limited number of yogurts were evaluated organoleptically, one pre pared with a ropy starter strain (NCFB at 12, 14.5 and 17% total solid s) and one prepared with a non-ropy strain (LL-I at 17% total solids). The results suggest that the ropy strain yogurts had different mouthf eel from the non-ropy strain yogurts; the most acceptable product over all was the ropy strain made with 12% total solids.