Use of Carnobacterium spp protective culture in MAP packed Ricotta fresca cheese to control Pseudomonas spp.

Use of Carnobacterium spp protective culture in MAP packed Ricotta fresca cheese to control Pseudomonas spp. Food Microbiol. 2018 Sep;74:50-56 Authors: Spanu C, Piras F, Mocci AM, Nieddu G, De Santis EPL, Scarano C Abstract Ricotta fresca is a whey cheese susceptible of secondary contamination, mainly from Pseudomonas spp. The extension of the shelf life of refrigerated ricotta fresca could be obtained using protective cultures inhibiting the growth of this spoilage microorganism. A commercial biopreservative, Lyofast CNBAL, comprising Carnobacterium spp was tested against Pseudomonas spp. The surface of ricotta fresca samples were inoculated either with Pseudomonas spp or Pseudomonas and Carnobacterium spp. Samples were MAP packed, stored at 4 °C and analyzed the day of the inoculum and 7, 14 and 21 days after the contamination. Microbiological analyses included total bacterial count, mesophilic lactic acid bacteria, Enterobacteriaceae, Pseudomonas spp, Listeria monocytogenes, moulds and yeasts. Pseudomonas mean initial contamination level was comparable in blank and artificially inoculated samples, respectively with values of 2.15 ± 0.21 and 2.34 ± 0.26 log cfu g-1. Carnobacterium spp. significantly reduced the growth of Pseudomonas spp respectively of 1.28 log and 0.83 log after 14 and 21 days of refrigerated storage. Intrinsic properties and physico-chemical composition were also investigated. Limited variation of pH...
Source: Food Microbiology - Category: Food Science Authors: Tags: Food Microbiol Source Type: research