Comparative efficacy of sodium lactate and Natamycin against discoloration and spoilage of fresh beef during chilled storage

Comparative efficacy of sodium lactate and Natamycin as preservative against discoloration and spoilage of fresh beef stored at 4 degrees C were evaluated. Fresh beef was treated with 3 g/L sodium lactate and Natamycin, respectively, and sterilized physiological saline was used as negative control. The spoilage of beef samples was monitored by pH, total volatile basic nitrogen (TVB-N), discoloration, sensory analysis and bacterial quality which were determined by culture-dependent and culture-independent analyses. The acceptable shelf life of fresh beef treated by sodium lactate and Natamycin reached 6 days and 4 days, respectively. Whereas, the control sample was acceptable for 3 days. The two kinds of preservative were conducive to hygiene levels improvement. Lactobacillus spp. and Weissella spp. sharply displaced the Ralstoni spp. with high potential spoilage and became the predominant bacteria, and the proliferation of Serratia spp. as the representatives' genus of psychrotrophic Enterobacteriaceae were completely controlled in the preservative treated samples. Sodium lactate displayed a remarkable efficacy against discoloration and spoilage of chilled beef, resulting in shelf life extension by 3-4 days. Natamycin has a remarkable antibacterial efficacy but a little efficacy against discoloration. Thus, sodium lactate is more suitable for freshness promotion of chilled beef.