Shelf Life Extension of Chilled Pork by Optimal Ultrasonicated Ceylon Spinach (Basella alba) Extracts: Physicochemical and Microbial Properties

Abstract

The effect of ultrasonication on the antioxidant and antibacterial properties of Ceylon spinach (<i>Basella alba</i>) extracts (CE) and the shelf life of chilled pork with CE were studied. The CE were ultrasonicated at different power levels (60-100%) for 10-40 min in an ultrasonic bath with the rise of antioxidant activities (<i>p</i> ≤ 0.05) proportional to the ultrasonication time. The additional investigation of antibacterial activities showed that the ultrasonicated extracts (100 mg/mL) could inhibit and inactivate <i>Staphylococcus aureus</i> and <i>Escherichia coli</i> with the optimal condition of 80% power for 40 min. For shelf-life testing, fresh pork treated with the ultrasonicated extracts at 100 and 120 mg/mL had lower values of thiobarbituric acid reactive substances (TBARS) than the control (without dipping). For food safety as measured by the total microbial count, the fresh pork dipped with 100-120 mg/mL CE extract could be kept at 0 °C for 7 days, 2 to 3 days longer than control meat at 0 and 4 °C, respectively. A sensory evaluation using a nine-point hedonic scale showed that fresh pork dipped with 100-mg/mL CE extracts was accepted by consumers. It is suggested that CE extracts can be applied in the food industry to enhance the quality and extend the shelf life of meat products.