Introduction: The spoilage microorganisms colonize cooked ham packaged in modified atmosphere with a preferential growth of psychotropic lactic acid bacteria (LAB) such as Leuconostoc, Lactobacillus, and Carnobacterium. Depending on the strains, the colonization can result in a premature spoilage, characterized by pH decrease, gas and slime production, discoloration, and/or off-flavors formation. Purpose: The purpose of the study was the isolation and identification of potential bioprotective starters: starting from a careful selection based on their physiological properties, starters will be designed to extend shelf-life and to meet food safety. Method: The first step of the project aimed to identify the main consortia of microorganism in good-quality and spoiled sliced cooked ham by microbiological analysis. The interaction between consortia was then studied in order to screen for strains able to inhibit spoiled consortia. The isolated strains were screened for their antimicrobial activity by agar-well-diffusion assay. Strains showing antimicrobial activity were identified by molecular methods and PCR was used to amplify the genes of the known bacteriocins. Results: A total of about 150 strains were isolated and six of them, identified as Lactococcus lactis, were selected for their ability to inhibit a large number of spoiled consortia and for their ability to produce bacteriocins. Significance: The results provide information on the use of microbial starter for the extension of shelf life of meat products as cooked ham. The effectiveness of potentially protective starters will be evaluated by challenge tests analyzing sensorial and microbial profiles.

Selection of Bioprotective Starter For Cooked ham

Valentina Alessandria;CARTA, VALERIO;Luca Cocolin
2018-01-01

Abstract

Introduction: The spoilage microorganisms colonize cooked ham packaged in modified atmosphere with a preferential growth of psychotropic lactic acid bacteria (LAB) such as Leuconostoc, Lactobacillus, and Carnobacterium. Depending on the strains, the colonization can result in a premature spoilage, characterized by pH decrease, gas and slime production, discoloration, and/or off-flavors formation. Purpose: The purpose of the study was the isolation and identification of potential bioprotective starters: starting from a careful selection based on their physiological properties, starters will be designed to extend shelf-life and to meet food safety. Method: The first step of the project aimed to identify the main consortia of microorganism in good-quality and spoiled sliced cooked ham by microbiological analysis. The interaction between consortia was then studied in order to screen for strains able to inhibit spoiled consortia. The isolated strains were screened for their antimicrobial activity by agar-well-diffusion assay. Strains showing antimicrobial activity were identified by molecular methods and PCR was used to amplify the genes of the known bacteriocins. Results: A total of about 150 strains were isolated and six of them, identified as Lactococcus lactis, were selected for their ability to inhibit a large number of spoiled consortia and for their ability to produce bacteriocins. Significance: The results provide information on the use of microbial starter for the extension of shelf life of meat products as cooked ham. The effectiveness of potentially protective starters will be evaluated by challenge tests analyzing sensorial and microbial profiles.
2018
IAFP European Symposium on food Safety
Stoccolma
25-27 Aprile 2018
IAFP European Symposium on food Safety
International Association for Food Protection
86
86
Valentina Alessandria, Valerio Carta, Veronique Zuliani, Jakob Soeltoft-Jensen, Tim Martin Seibert, Luca Cocolin
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/2318/1667294
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