Sodium Chloride Effect on Autoxidation of the Lard Component of a Gel

SUMMARY: Stable gels composed of lard, sodium carbomethoxy cellulose and water were used for the examination of factors involved in the pro- and antioxidant activities of sodium chloride, other inorganic salts, heme compounds, meat fractions and other additives. Autoxidation processes were evaluated by peroxide and monocarbonyl determinations. The solid translucent gels, in which additives had been incorporated, were stored frozen, freeze-dried or allowed to oxidize without physical change. The hydrated gels were well aerated in preparation and oxidized in the dark at a convenient pace at 20°C. When the gel was freeze-dried, a sponge-like structure was obtained which, after an induction period, autoxidized rapidly. Freezer-stored gels autoxidized at a rate roughly similar to freezer-stored meat. Sodium chloride had a direct pro-oxidant action on the lard of freezer-stored and dehydrated gels. Hydrated gels containing NaCl when stored at 20°C had an inhibiting autoxidation pattern somewhat similar to the quantitative influence of NaCl on pH. Ethylene-diaminetetraacetate (EDJA) had a powerful antioxidant influence. Sodium chloride accelerated heme catalysis regardless of the presence of antioxidant or chelator. Interesting differences in monocarbonyl patterns and monocarbonyl/peroxide ratios as influenced by additives and moisture content of the gels were observed.