Effect of rosemary extracts on the antimicrobial activity and quality of minced pork during refrigerated storage

摘要

Rosemary is well known as a very promising dietary antioxidant. The antimicrobial activities of 80% ethanol crude extract and four subfractions (petroleum ether fraction, ethyl acetate fraction, butanol fraction, and aqueous fraction) from rosemary to test strains were investigated by the Oxford-cup assay. The results revealed that petroleum ether fraction, ethyl acetate fraction, and crude extract exhibited a good antimicrobial activity to test strains. Petroleum ether fraction had the best antimicrobial activity, while butanol fraction and aqueous fraction only had an antimicrobial action on Proteus vulgaris Hauser. Besides, the effect of petroleum ether fraction, ethyl acetate fraction, and crude extract on minced pork stored for 15 days at 4°C were compared, respectively. In addition, sensory evaluation, Total Bacterial Count (TBC), pH, the values of Malondialdehyde (MDA), and Conjugated Dienes (CD) were used as a criterion. The results evidenced that petroleum ether fraction treatment was obviously better than other subfractions in minced pork. Five major compounds were identified by High-Performance Liquid Chromatography-Mass Spectroscopy (HPLC-MS). It has been concluded that petroleum ether fraction had better antimicrobial, preservative, and antioxidant capacities in minced pork, which might be at least partially associated with its interactions with high contents of carnosol and carnosic acid.