LARGE MICROBIOTA SURVEY REVEALS HOW THE MICROBIAL ECOLOGY OF COOKED HAM IS SHAPED BY DIFFERENT PROCESSING STEPS

Abstract

ABSTRACTThe production of cooked ham involves numerous steps shaping the microbial communities of the final product, with consequences on spoilage metabolites production. To identify the main factors driving the ecology of ham and its spoilage, we designed a study encompassing five variables related to ham production: type of storage during meat transportation, churning speed, drain-off time, slicing line and O2packaging permeability. We obtained about 200 samples from the same facility and we characterizedi)their microbiota based ongyrBamplicon sequencingii) their production of spoilage-related metabolites based on E-Nose analysis and enzymatic assays. The slicing was the most critical step, shaping two general types of microbiota according to the slicing line: one dominated byCarnobacterium divergensand another one dominated byLeuconostoc carnosumandSerratia proteamaculans. Regarding metabolites production,L. carnosumwas associated to D-lactic acid, ethanol and acetic acid production, whereasSerratia proteamaculanswas associated to acetic acid production. This last species prevailed with highly O2-permeable packaging. Within a given slicing line, we observed campaign-based variations, withLactobacillus sakei,Leuconostoc mesenteroidesandCarnobacterium maltaromaticumprevalent in summer.L. sakeiwas associated with L-lactic acid production andC. maltaromaticumwith formic and acetic acid productions.