PROTEINASE ACTIVITY OF NONSTARTER LACTOBACILLI

The proteinase activity of non-starter lactobacilli previously isolated from mature good quality Cheddar cheese was investigated in order to select a suitable organism for influencing cheese flavour. These organisms all possessed relatively low proteinase activity which was not adversely affected by the temperature and pH conditions encountered during the manufacturing process. Further the non-starter lactobacilli proteinase system was more tolerant to the NaCl concentration in Cheddar cheese and was able to degrade milk proteins, particularly alpha-s1-casein, more efficiently under cheese maturation conditions than the starter organism L. lactis subsp. cremoris BK5. There was a difference in the peptide patterns produced when protein digests were examined by HPLC.