Histamine and microbiological changes during storage of semi-preserved anchovies

During the various stages of manufacture of semi-preserved anchovies, histamine shows a significant increase favored by the fragility of anchovies and wealth histidine, an amino acid precursor of histamine. The decarboxylation of histidine is present as a major problem in the industry of semi-preserved anchovies, especially during the ripening step. The objective of this work is to monitor the levels of alteration in a final product subjected to aging by incubation at 30°C ± 1. Accumulation of histamine, as well as microbial population in semi preserved anchovies were investigated. Enterobacteriaceae and Lactobacilli do not seem to resist to the salt applied to the product. They disappear within one month of storage. A total of 665 bacterial strains were selected from the prescreening step using various selective media. Only 20.6% of these selected isolates showed a positive reaction in Niven’s differential medium, and 31.4% of the positive isolates were true histamine formers when confirmed by thin layer chromatographie. The values of histamine remain in close contact with the sanitary measures taken by each company. Regular monitoring and mastering of good practices are necessary for a good quality product.