Suitability of log-linear models to evaluate the microbiological quality of baby clams (Chamelea gallina L.) harvested in the Adriatic Sea

The presence of Fecal coliforms or Escherichia coli in baby clams (Chamelea gallina L.) is considered an indicator related to their safety because the y can be correlated with the presence of pathogenic bacteria. For this reas on the Italian regulation has defined limits for these microorganisms. The presence of these microbial indicators is dependent on various environmenta l variables, In this work all the variables considered are categorical and, consequently, the traditional approach of predictive microbiology was not applicable. The data were summarized by means of a cross-tabulation and ana lyzed using the log-linear model technique. This statistical technique is w idely used in social and economic studies but only partially developed in f ood microbiology. The suitability of the log-linear model to analyse microb iological data in relation to environmental variables was evaluated. In par ticular, the microbiological quality of baby clams harvested in five differ ent areas of the Adriatic Sea. coast in Emilia Romagna (Italy) was consider ed. The influence of the season and geographical origin on microbiological standards was assessed. A legit model was developed to predict the frequenc ies, depending on geographical origin and season, of samples with concentra tions of the indicator organisms below or above the legal standards provide d by Italian regulation. (C) 2000 Elsevier Science B.V. All rights reserved .