EN
Belly flaps of frozen cod fillets not suitable for consumption because of parasitic contamination were used as a raw material to obtain peptones for microbiological purposes. Hydrolysis on a laboratory scale was being performed for 6 hours in a reaction mixture; it contained 5 parts of minced fish meat and 1 part of minced porcine pancreas (temperature 40°C, pH 7.0). The hydrolysates contained 0.8% of total nitrogen, 0.1% of alfa-amino nitrogen and 3.8% of ash. The colour of the hydrolysates was similar to that of standard peptones. Their slightly perceptible fish smell was not assessed as a negative feature. The growth promoting activity of the cod peptones was compared with that of Bacto-Tryptone, Bacto-Tryptose, Bacto-Peptone, and Proteose-Peptone. The growth of E. coli and Staph. aureus strains was better on media based on the fish peptones than that on commercially available peptones.