Bio-Preservation Challenge for Shelf-Life and Safety Improvement of Minced Beef

Abstract

Bio preservation systems are of increasing interest for food industry and consumers. Bacteriocinogenic lactic acid bacteria and/or their isolated bacteriocins are considered safe additives (GRAS), useful to control the frequent development of pathogens and spoilage microorganisms in foods. The role of lactic acid bacteria (L. acidophilus) as a trail (I) compared to a probiotic bacteriocin (nisin) as a trail (II) individually and in combination (combined tail, trail III) as bio-preservative agents on shelf-life and safety of L. monocytogenes injected in minced beef samples was studied during cold storage (4°C). The results showed that pH, total volatile basic nitrogen (TVB-N) and thiobarbituric acid values were markedly decreased in all treated samples as compared to untreated (control) sample. On the other hand, there was a good antibacterial activity of the investigated trails on total aerobic (TAC), Enterobacteriaceae (TEC) and total coliform (TCC) counts but the activity decreased through out the storage time. Consequently, results indicated that probiotic bacteria and bacteriocin had a positive effect on the shelf-life of treated samples compared to untreated ones by the manner of trail (I), combined trail and lastly trail (II). The samples treated with nisin (trail I) showed the best results as long shelf-life (6 days) compared to those of other trails. It could also be observed that the potential of probiotics to inhibit growth of common foodborne L. monocytogenes was different as combined trail (18.2, 29.1,40, 47.3 and 61.8%), trail (I) (12.7, 23.6, 32.7, 43.6, 4.8 and 50.9%), trail (II) (14.5, 20, 25.5 and 38.2%) and control samples (zero%) where, combined trail samples that were treated with both nisin and L. acidophilus culture was the superior one. In conclusion, no single probiotic agent could cover all the requirements for food preservation and safety. It is often practical, however, to use a combination of bio preservatives and preservative factors to achieve this goal.