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Accleration of fish sauce fermentation using proteolytic enzymes

To help you further specialized material Chemistry serving the needs of learning and research, invite you to refer to the contents of the document "Accleration of fish sauce fermentation using proteolytic enzymes". Hope content useful document for the learning needs and research. | ACCELERATION OF FISH SAUCE FERMENTATION USING PROTEOLYTIC ENZYMES by Ravipim Chaveesuk A thesis sumitted to the Faculty of Graduate Studies and Research in partial fulfilment of the requirements for the degree of Master of Science. Department of Food Science and Agricultural Chemistry Macdonald Campus of McGill University Montreal P.Q. Canada July 1991 ABSTRACT Fish sauce fermentation is widely used in Southeast Asia as a means of preservation and producing valued added products from underutilized fish species. First grade and second grade Nampla commercially produced Thai fish sauces were analyzed for their chemical and microbiological composition first grade commercially produced Nampla contained higher amounts of total nittogen formol niưogen free and total amino acids compared to second grade sauce. Most of the essential amino acids were present in both grades of sauces. Low microbial counts of halotolerant microorganisms were observed in both sauces. The use of trypsin and chymotrypsin to accelerate the rate of fish sauce fermentation produced from herring one of the underutilized fish species in Quebec was investigated. Results showed that supplementation with trypsin and chymotrypsin increased significantly the rate of proteolysis the amounts of total nitrogen formol nifrogen and free amino acids in the final fish sauces pcO.OS . Fermentation time was also reduced from 6-12 months to 2 months. A significant increase in total nhrogen and free amino acid contents in the end products was observed when the enzyme concentration was increased from 0.3 to 0.6 p 0.05 . Supplementation with 0.6 of 25 75 trypsin chymotrypsin showed the most satisfactory results in terms of total niữogen formol nitrogen and free amino acid contents. However the levels of free amino acids and volatile bases in herring sauces produced with various proportions of 0.6 trypsin and chymotrypsin were significantly lower than in first grade commercially produced Nampla. Results of sensory .