Beneficial effects of commercial Assam green tea infusion on the microbial growth and oxidative stability of cooked beef

Abstract

Natural preservatives having the great antioxidant and antimicrobial activity have been utilized in the food industry for many years. In the present study, the effect of of two brands of commercial Assam green tea infusion (represented by A and B) and 0.02% BHA/BHT on microbial growth, anti-lipid oxidation and color change were investigated in cooked beef. The green tea concentration has influenced to the results. It was found that A and B at the concentration of 250 mg/mL significantly reduced the population of Staphylococcus aureus, Listeria monocytogenes, Salmonella typhimurium and E. coli in the cooked beef to an undetectable level within 2 days of storage at 4°C. A and B also exhibited higher anti-lipid oxidation activity compared to 0.02% BHA/BHT, and control. Assam green tea infusions in cooked beef significantly increased δ L* value and decreased δ a* and δ b* value (p ≤ 0.05). These indicate that Assam green tea infusion might be a potential candidate as a natural preservative for beef and other types of food.