Influence of processing on the degradation of pesticides in meat products.

The influence of processing on the degradation of C-14 labelled DDT, γ-hexachlorocyclohexane (γ-HCH) and monolinuron (MLN) was investigated. In culture media micrococci and yeasts metabolised DDT, mainly to DDD, within two weeks, whereas γ-HCH and MLN were negligibly degraded. Only small amounts of the pesticides were metabolised by lactobacilli. Meat of rabbits fed with C-14 labelled pesticides was used to prepare various meat products. In dry sausages with nitrite-curing salt (NCS) up to 60% residual DDT and 70% γ-HCH were recovered. In the presence of a starter culture and nitrate the rate of degradation was lower, 76% DDT (after 38 days) and 77% of γ-HCH (after 30 days) of the initial concentrations were found in the final products. In M. Long. dorsi 61% DDT and 80% γ-HCH were still present after curing. In cured, cooked meats 87% DDT but only 35% γ-HCH of the initial amounts were left. In the case of MLN about 50% of the radioactivity was removed by curing, hot-smoking or cooking; only 2% of the radioactive material was extracteble. The enzymic degradation of DDT, γ-HCH and MLN, respectively, by muscle mitochondria (released after freezing) amounted to about 10% on average. In liver sausage mixtures with sodium chloride, DDT and γ-HCH were metabolised to a greater extent than in mixtures containing NCS or NCS and sodium ascorbate (NaASC). A modified ascorbic acid oxidation system did not enhance the degradation of the pesticides investigated to a significant extent in a cervelat type sausage.