Inhibition of Clostridium botulinum by Nα- Cocoil-L-Arginine Ethylester•DL- Pyrrolidone Carbonate in Meat

Abstract

Nitrite has been used as a curing agent for meat products. The purposes of nitrite addition are to inhibit outgrowth of Clostridium botulinum spores and to produce the characteristic heat stable red color and cured meat flavor. However, nitrite produces carcinogenic nitroso compounds. Therefore, substitutive compounds for nitrite have been searched. Amino acid derivatives have reported to have antimicrobial effect and they are considered as safety compounds when we used as food preservatives. Among them, N^α-cocoll-L-arginine ethylester•DL-pyrrolidone carbonate (CAE) has strong inhibitory effect to Escherichia coil, Bacillus subtilis, Staphylococcus aureus, etc. We have observed 25 ppm of CAE was inhibitory to growth and toxin production of C. botulinum okra in PYG medium incubated at 30°C for 8 days. The objective of this paper is to determine the inhibitory effect of CAE on toxin production of C. botulinum okra in meat. The inhibitory effect of CAE in meat was about equal to that of sorbate. In raw meat system containing minced pork, 2% NaCl and CAE, toxin production was reduced to one tenth of that of control by addition of 10, 000 ppm of CAE. When spores were inoculated after minced meat was heated at 100°C for 2min, 2, 500 ppm of CAE was necessary to reduce toxin production to one tenth of that of control. We supposed that CAE was less effective in meat system than in laboratory medium because it was partly adsorbed to meat protein. The effect of nitrite on inhibitory activity of CAE was also studied. The inhibitory ffect of 100 ppm of CAE plus 50 ppm of nitrite was about equal to that of 2, 500 ppm of CAE or 150 ppm of nitrite. CAE was tested for mutagenicity by using a microsomal test system with Salmonella typhimurium TA 98 and TA 100. No mutagenicity was observed with CAE. CAE is possible to use as substitutive compound for nitrite.