Applicazione della metodica Biolog per la valutazione di un trattamento sanetizzante con acqua clorata in insalate di IV gamma

The present work is part of a wider research aimed to ascertain various utilization possibilities for Biolog methodology of metabolic mark. In particular such methodology was employed, in collaboration with the factory Salads and Fruits (Casteggio, Piacenza, Italy), in order to evaluate the sanitizing effect of a treatment with chlorinated water on microbial populations of plant material for the production of ready-to-rat-salads. Microbial populations were extracted from plant material at various steps of the treatment, and successively at the packaging step and after a week of storage at 4°C. Populations were then inoculated in Biolog EcoMicroplates and submitted to suitable incubation. For each of them the corresponding curve of its metabolic activity was so obtained. Experimental curves were modelled by fitting to Gompertz's and Lindstrom equation, and the values of the equation's constants were used for comparison purposes, in order to assess possible differences within microbial populations at the various steps. The treatment under study is performed with chlorinated water and causes a reduction of microbial contamination. This is particularly strong in the first step, but the effect diminishes in the subsequent ones, so that during the conservation (4°C) of the packaged product microbial proliferation undergoes a certain increase, while remaining within the limits of tolerance for product acceptability.