Inhibitory Effects of oxalic acid on Listeria monocytogenes , Salmonella Enteritidis and Escherichia coli O157:H7 inoculated onto Chicken Breast stored at 4°C

Oxalic acid was evaluated for its effectiveness in inhibiting growth of selected pathogens on raw chicken breasts. Inoculated chicken breasts were dipped in oxalic acid solutions (0, 0.5, 1.0, 1.5 and 2.0% w/v) for 10, 20, and 30 min, packed in oxygenpermeable polyethylene bags, and stored at 4°C. Oxalic acid residues were determined using HPLC method. Counts of pathogens on chicken breasts were determined on days 0, 2, 5, 7, 10, and 14 after storage. Maximum oxalic acid concentration in unwashed chicken breast was 36 mg/100g. Washing of chicken reduced oxalic acid concentration by 50%. Oxalic acid concentration in cooked breast was 2mg/100g which is quite lower than levels in vegetables and herbs, used in daily diets. Chicken meat treated with oxalic acid could therefore be safe for human consumption. Reduction by 2.87, 2.02 and 4.12 log CFU/g, of L. monocytogenes, S. Enteritidis and E. coli O157:H7 respectively was observed in treated samples. Counts of the pathogens in treated samples decreased compared to untreated samples during 14 days storage. Sensory evaluation of cooked oxalic acid treated samples was acceptable to consumers after 14 days of storage. It was evident that oxalic acid has great potential for decontamination of chicken carcasses.