Lactic Bulk Starter Homogenization Affects Culture Agglutination

Four commercial lactococcal cultures (three agglutinating, one nonagglutinating) grown in an internal pH‐controlled medium were homogenized at various pressures to determine the effect of homogenization on bulk starter agglutination. Severity of agglutination was determined in skim milk that had been inoculated with these bulk starters. As homogenization pressure increased, bacterial agglutination decreased. Homogenization decreased culture agglutination by breaking chains and clumps of cells apart. A pressure of 176 kg/cm2 was optimal for two of the agglutinating cultures, but 246 kg/cm2 was required for the third culture. Homogenization of the nonagglutinating culture at 246 kg/cm2 decreased rate of acid production in skim milk, suggesting that cellular damage had occurred. Copyright © 1992, Wiley Blackwell. All rights reserved