Sulphite-free lamb burger meat: antimicrobial and antioxidant properties of green tea and carvacrol.

BACKGROUND Sulfite is commonly used to preserve lamb burger meat in the EU. Nevertheless, its consumption has been related to certain health problems, which has increased consumer demand for sulfite-free products. Natural compounds with antioxidant and antimicrobial properties may be a feasible alternative to preserve lamb burger meat. This study evaluated the antimicrobial and antioxidant properties of carvacrol, green tea and their combination in preserving lamb burger meat. Their effect was also compared with that of 400 ppm sulfite. RESULTS Lamb burger meat was mixed with different concentrations of the extracts, packaged aerobically and displayed for 8 days at 4 degrees C. Total polyphenols, thiobarbituric acid reactive substances, colour, and microbial and sensory analyses were performed. Both green tea and carvacrol avoided lipid oxidation even at 300 ppm, while only carvacrol, which showed a concentration-dependent action, delayed discolouration and microbial growth. Carvacrol and green tea also limited the development of oxidation odour and flavour, but the former brought about herbal odours and flavours to the meat. On the other hand, sulfite provided a higher colour stability and lower microbial counts than both natural compounds but presented a higher lipid oxidation. CONCLUSION Carvacrol seems to be a promising alternative to replace sulfite in lamb burger meat, whereas green tea should be combined with an antimicrobial agent. (c) 2018 Society of Chemical Industry