Supercritical extracts of wild thyme (Thymus serpyllum L.) by-product as natural antioxidants in ground pork patties

The effects of wild thyme by-products (Thymus serpyllum L.) from supercritical fluid extraction SFE1 (100 bar and 40 degrees C) and SFE2 (350 bar and 50 degrees C) on the quality of ground pork patties evaluated by pH, CIE-color, lipid (TBARS test) and protein oxidation (thiol group content) and microbiological profile. SFE extracts were added to ground pork patties as: 0.075 mu L/g of SFE1 (T1), 0.150 mu L/g of SFE1 (T2), 0.075 mu L/g of SFE2 (T3), 0.150 mu L/g of SFE2 (T4), while SFEs (T5) was control without any extracts. SFE1 and SFE2 were protective against color degradation. Moreover, the addition of SFE1 and SFE2 significantly reduced lipid and protein oxidation in the patties (p <= 0.05). Furthermore, lower concentration of SFE2 reduced total plate count to < 6 log cfu/g after 3 days of storage. Obtained results indicated that SFEs of wild thyme by-product are useful as natural antioxidants and antimicrobial agents in meat processing.