Isolation and Identification of Lactobacillus plantarum C010 and Growth Kinetics of its Batch Fermentation

Chilled pork is pursuit by people due to its delicious and delicate taste, but it is still susceptible to microbial contamination even under refrigerated conditions. Consequently, to explore microbial preservatives for chilled pork, in this study, the specific spoilage organism Pseudomonas koreensis PS1 from spoiled chilled pork as the indicator was used to isolate the bacteriocin-producing lactic acid bacteria from the soils and fresh cow dungs. Among six bacteriocin-producing bacteria from 182 isolates, the strain C010 with higher-yielding, broad-spectrum, subculture stability and protease (pepsin, trypsin and proteinase K) sensitive was selected and identified as Lactobacillus plantarum based on morphological, biochemical and 16S rDNA gene sequence analysis. Simultaneously, the crude bacteriocin of L. plantarum C010 was stable under high temperature and ultraviolet conditions. The kinetics of bacterial growth and bacteriocin production of L. plantarum C010 were analyzed in batch fermentation. Bacteriocin was produced throughout the logarithmic growth phase and the Leudeking-piret model could characterize the synthesis of bacteriocin well. This present study indicates that bacteriocin-producing L. plantarum C010 has promising potentials to control the specific spoilage organism and can be used as the bio-preservative in food.

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

The effect of ultrasonication on the antioxidant and antibacterial properties of Ceylon spinach (Basella alba) 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 (p ≤ 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 Staphylococcus aureus and Escherichia coli 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.

Analysis of the results of microbiological studies of samples of chilled pork and beef meat using traditional and advanced techniques

The article analyzes microbiological studies of meat raw materials obtained using traditional methods of determination and using ready-made test systems. The most promising direction for the development of modern sanitary microbiology at the present time is the use of modern chromogenic medium and ready-made test systems.