Use of Bacteria to Improve Healthy Properties of Fatty Acids in Dry Cured-Meat Products

Abstract

related bacteria, such as propionibacteria, bifidobacteria and lactic acid bacteria. The aimof this researchwas to evaluate the production of bioactive CLA isomers cis-9, trans-11 C18:2 and trans-10, cis-12 C18:2 by Lactobacillus caseiand Lactobacillus plantarumgroup strains isolated from raw milk traditional Italian ewe cheeses. A total of 30 strains were grown in MRS broth containing emulsifiers (e.g BSA, Tween 80), skim milk, or resuspended as resting cells in buffer system, all enriched with 0.5mg ml-1 LA. After incubation at 30 37 ◦C for 24 72h, variable CLA concentrations were observed: interestingly, cis-9, trans-11 C18:2 and trans-10, cis-12 C18:2, represented more than 90% of total CLA. In particular, some L. plantarum strains showed a production of about 200 g ml-1 of cis-9, trans-11 C18:2 isomer in skim milk. In general, CLA bioconversion from LA was strain dependent and greatly influenced by pre-cultivation system, medium and pH of cultivation, phase of growth or resting cell condition, as well as parameters of incubation. Based on the above results and due to the GRAS or probiotic status of many L. caseiand L. plantarumgroup strains, some of them could represent good candidates to produce fermented milk/cheeses enriched in CLA or CLA ingredients.