CONICET | Buscador de Institutos y Recursos Humanos

A B S T R A C TThe halophilic microbial community of the salted-ripened anchovy process was studied. Samples from rawmaterials (salt and fresh anchovies) and from the stages of brining and ripening were collected and analyzed fortheir bacterial counts at 15 and 20% NaCl. No halophilic colonies were found in fresh anchovy and counts ofabout 103 CFU/g were determined in salt samples. A fluctuation of bacterial counts during the process wasfound. At the end of brining, ~104 CFU/g were determined in anchovy samples and this value was reduced tonot detectable counts at the beginning of the ripening stage. After one month, counts increased to ~104 CFU/gand remained stable until the end of the process.From each sample, colonies having different morphotypes were isolated and submitted to a macro and microscopiccharacterization, a study of salt requirement for growth, and biochemical and phenotypic tests. Theresults were submitted to Univariate, Bivariate and Multiple Correspondence Factorial Analysis (MCFA). A totalof 79 colonies were isolated during the salting-ripening anchovy process. Among the isolates, about 40?50% waspositive for indole production and lipolytic activity and a 25% showed ability to produce H2S and proteolyticcapacity. Proteolytic and lipolytic activities were well balanced along the process and resulted independent fromthe isolation stage, which is a desirable condition due to the contribution of microbial proteolysis and lipolysis tothe development of texture and final aroma, respectively. H2S and indole producers practically were not detectedduring ripening. This fact is important because indole and H2S are associated with the development of off-flavorsand spoilage in salted fish products. MFCA and Cluster Analyses complemented the Bivariate Analyses. Thefactor map showed proximity between the isolates from salt samples and from ripening. Isolates were statisticallyclustered in two groups. Cluster 1 grouped non-desirable activities (H2S and indole production) withcultures proceeding from brining whereas Cluster 2 related isolates mainly from salt samples and during ripeningwith some desirable microbial capacities (Cytochrome oxidase activity and non-H2S and non-indole production).These results would indicate that during the ripening process of salted anchovies, a natural selection of beneficialmicroorganisms for the development of the typical product sensory attributes occurred.