EFFECT OF ENHANCED PROTEOLYSIS ON FORMATION OF BIOGENIC-AMINES BY LACTOBACILLI DURING GOUDA CHEESE RIPENING

The effect of enhanced proteolysis on amine formation by amino acid de carboxylase positive Lactobacillus sp. during Gouda cheese ripening wa s examined. A commercial proteolytic enzyme preparation was added to p asteurized milk prior to cheese preparation. The effect of this manipu lation on the formation of putrescine, histamine and tyramine was inve stigated in the presence and absence of amino acid decarboxylase-posit ive strains during a 12-week ripening period. Four batches were supple mented with a proteolytic enzyme. Batch I contained the proteolytic en zyme only, whereas batches II-IV were additionally supplemented with L actobacillus delbrueckii LTH 1260 (batch II), Lactobacillus buchneri L TH 1388 (batch III) or Lactobacillus brevis LTH 2560 (batch IV). In ba tch I putrescine was detected with 4 mg/kg, in batch II, 42 mg/kg putr escine, 238 mg/kg histamine and 636 mg/kg tyramine were found. Batch I II contained 13 mg/kg putrescine and 418 mg/kg histamine, whereas in b atch IV, 26 mg/kg putrescine and 776 mg/kg tyramine were present. Batc h V was supplemented with all three lactobacilli but did not contain t he proteolytic enzyme. In this experiment, 4 mg/kg putrescine, 179 mg/ kg histamine and 337 mg/kg tyramine were detected. A control cheese ba tch (VI) without addition of amine forming lactobacilli or a proteolyt ic enzyme was produced and only 4 mg/kg putrescine were detected. An i ncrease in amine concentration during cheese ripening under conditions of enhanced proteolysis in the presence of starter and spoilage lacto bacilli was evident from the experiments. (C) 1998 Elsevier Science B. V. All rights reserved.