The effect of rosemary extract and lactic acid on the quality of refrigerated broiler fillets.

The current study investigated the effect of rosemary extract (0.2% RE) and lactic acid (1% LA) on some freshness, bacterial parameters and formation of biogenic amines during refrigeration of broiler fillets. Ninety broiler fillet samples were divided into three groups (each 30). The control group was dipped in sterile distilled water, while the RE and LA groups were dipped in rosemary extract 0.2% (w/v) and lactic acid 1% (w/v), respectively. Sensory evaluation, pH, total volatile basic nitrogen (TVB-N), thiobarbituric acid reactive substances (TBARS), total psychrotrophic and Enterobacteriaceae counts were performed at zero time and at 3 days interval until the group were rejected from sensory analysis. Organoleptic scores were unacceptable after the 9th, 12th and 15th day of refrigeration in control, RE and LA groups, respectively. TVB-N was the lowest in LA group (3rd day; 4.36 ± 0.12, 6th day; 5.62 ± 0.7 and 9th day; 10.13 ± 0.98) when compared with the RE and control groups. Moreover, TBARS was the highest in the control group (3rd day; 0.22 ± 0.06, 6th day; 0.39 ± 0.07 and 9th day; 0.78 ± 0.09) when compared with the RE and LA groups. LA group showed the lowest number of psychrotrophic bacteria during refrigeration period when compared with the other groups. Enterbacteriaceae was detected at zero, 3rd and 6th day in control, RE and LA groups, respectively. This study concluded that dipping in LA 1% or RE 0.2% reduce the psychrotrophic and Enterobacteriaceae bacteria of broiler fillet and increased the acceptability of refrigerated fillet, decreased the biogenic amines formation and rancidity. Therefore, broiler fillets dipped in RE 0.2% or LA 1% can be used up to 12 or 15 days when refrigerated at 4 °C.