Could halophilic archaea improve the traditional salted anchovies (Engraulis encrasicholus L) manufacture?

Abstract

Although initial interest on extremely halophilic archaea turned to their involvement in the spoilage of salted meat and fish products, studies on the occurrence of such microorganisms in food ecosystems have rarely been performed. During salted anchovies production, a traditional process used by Mediterranean fishermen to obtain a tender product with a specific pleasant aroma and taste, extremely halophilic archaea belonging to the Halobacteriaceae family are often isolated. In order to elucidate the influence of halobacteria in salting and curing of this product, an experimental manufacturing was performed according to a traditional procedure. Salt to be employed was artificially inoculated with two halobacterial strains referable to the species Halobacterium salinarum and Haloarcula marismortui selected ad hoc, by using a procedure tailored to reproduce the natural conditions of solar salterns. Main microbial groups, histamine, proteolysis and lipolysis were monitored throughout the production process. In all the media employed, bacterial loads in samples treated with a proteolytic strain of Halobacterium salinarum were lower then the loads of the other thesis considered. Remarkable differences emerged even from the histamine monitoring: in manufacture with not inoculated salt, levels of histamine in the early phase of fermentation reached values of about 600ppm. Products ready to be consumed were submitted to sensory analysis and to a panel for overall acceptability. In both cases anchovies produced with artificially inoculated salt exhibited a stronger aroma of typical anchovy sauce and lower flavours of putrid, rancid and unidentifiable off-flavours