The production of fermented foods is based on the use of starter cultures, for instance lactic acid bacteria that initiate rapid acidification of the raw material. Recently, new starter cultures of lactic acid bacteria with an industrially important functionality are being developed. The latter can contribute to the microbial safety or offer one or more organoleptic, technological, nutritional, or health advantages. Examples are lactic acid bacteria that produce antimicrobial substances, sugar polymers, sweeteners, aromatic compounds, vitamins, or useful enzymes, or that have probiotic properties.

http://mummified.persiangig.com/new_folder/lact1.pdf

Lactic acid bacteria as functional starter cultures for the food fermentation industry

Bacteriocin-based Strategies for Food Biopreservation

Food fermentations: role of microorganisms in food production and preservation.

http://sgpwe.izt.uam.mx/files/users/uami/acym/Enterococos_en_alimentos_y_salud-2006.pdf

The role and application of enterococci in food and health.

Biopreservation refers to extended storage life and enhanced safety of foods using the natural microflora and (or) their antibacterial products. Lactic acid bacteria have a major potential for use in biopreservation because they are safe to consume and during storage they naturally dominate the microflora of many foods. In milk, brined vegetables, many cereal products and meats with added carbohydrate, the growth of lactic acid bacteria produces a new food product. In raw meats and fish that are chill stored under vacuum or in an environment with elevated carbon dioxide concentration, the lactic acid bacteria become the dominant population and preserve the meat with a "hidden' fermentation. The same applies to processed meats provided that the lactic acid bacteria survive the heat treatment or they are inoculated onto the product after heat treatment. This paper reviews the current status and potential for controlled biopreservation of foods.

Biopreservation by lactic acid bacteria.

The behaviour of spoilage and pathogenic microorganisms was evaluated after high-pressure treatment (600 MPa 6 min, 31 8C) and during chilled storage at 4 8C for up to 120 days of commercial meat products. The objective was to determine if this pressure treatment is a valid process to reduce the safety risks associated with Salmonella and Listeria monocytogenes, and if it effectively avoids or delays the growth of spoilage microorganisms during the chilled storage time evaluated. The meat products covered by this study were cooked meat products (sliced cooked ham, pH 6.25, aw 0.978), dry cured meat products (sliced dry cured ham, pH 5.81, aw 0.890), and raw marinated meats (sliced marinated beef loin, pH 5.88, aw 0.985). HPP at 600 MPa for 6 min was an efficient method for avoiding the growth of yeasts and Enterobacteriaceae with a potential to produce off-flavours and for delaying the growth of lactic acid bacteria as spoilage microorganisms. HPP reduced the safety risks associated with Salmonella and L. monocytogenes in sliced marinated beef loin. D 2004 Elsevier Ltd. All rights reserved.

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Microbial inactivation after high-pressure processing at 600 MPa in commercial meat products over its shelf life

Functionalty of enterococci in meat products

Lactobacillus sake CTC494 isolated from a naturally fermented sausage, produced an antibacterial agent active against selected strains of Listeria monocytogenes and L. innocua. The agent was bacteriolytic against L. monocytogenes and sensitive to proteolytic enzymes ; it was identified as a bacteriocin and was designated as sakacin K. The ability of Lact. sake CTC494 to inhibit the growth of listeria, compared to a bacteriocinogenic negative control strain, was examined in a model sausage system and in dry fermented sausages. In dry fermented sausages Lact. sake CTC494 was able not only to suppress the growth of listeria but to diminish their number by 1.25 log compared to the non-bacteriocinogenic control strain. Thus, Lact. sake CTC494 has proved to be a good starter culture providing good organoleptical and sensorial qualities to the product and can be employed as a bioprotective starter culture in fermented meat products.

M.T. Aymerich

Papers

Microbial inactivation after high-pressure processing at 600 MPa in commercial meat products over its shelf life

Functionalty of enterococci in meat products

Inhibition of Listeria in dry fermented sausages by the bacteriocinogenic Lactobacillus sake CTC494

Bactericidal synergism through bacteriocins and high pressure in a meat model system during storage

Bacteriocin-producing lactobacilli in Spanish-style fermented sausages: characterization of bacteriocins