Antioxidant activity of sodium lactate in meat and model systems

Abstract

Antioxidant activity of sodium lactate (NaL) was investigated in meat and model systems as follows: (1) portions of raw ground pork were treated with BHT (0.1 g/kg, fat basis), NaL (10 or 20 g/kg, weight basis), non-vacuum packaged and stored in the dark at 0 and 5°C for 0, 3, 7, 10 and 14 d and the formation of thiobarbituric acid-reactive substances (TBA-RS) was monitored; (2) in model studies, the antioxidant activity of NaL (5 or 10 g/L), with reference to BHT (0.1 g/L) and BHA (0.1 g/L), was examined in a system consisting of linoleic acid (2.5 mmol/L) dispersed in phosphate buffer (25 mmol/L, pH 5.8) containing Tween-20 (5 g/L), ferric chloride (150 μmol/L) and ascorbate (100 μmol/L). Samples were stored in the dark at 25 ± 1°C for at least 72 h. Oxidation was estimated by peroxide value (PV), conjugated diene (CD), and TBA-RS. NaL suppressed oxidation in pork during up to 7 d storage at 0 and 5°C and compared well with BHT. In model studies, while BHT and BHA effectively controlled formation of oxidation indices, NaL was particularly effective in controlling TBA-RS formation. Inhibition of PV or CD formation by NaL appeared to be concentration dependent. Calcium lactate (CaL) showed similar activity. The mechanism of NaL antioxidant activity is proposed to be in part through Fe3+-lactate complexation or lactyl radical reduction of Fe3+ to Fe2+ and subsequent chelation of Fe2+ by the carboxylate species. © 1994 Academic Press.