Using a polynomial model for fungi from table olives

Summary Table olives are one of the most important fermented vegetables in the food industry because of their worldwide economic importance. Enterobacteriaceae , lactic acid bacteria and yeasts are among the most relevant microorganisms involved in olive fermentation determining safety, quality and flavour of the final product. Fungi can play a double role during table olive processing acting as spoilage or desirable microorganisms. This article addresses the effects of some factors ( pH , NaCl, temperature, phenols) on the growth/survival of yeasts and moulds, both some wild isolates from olive brine and some yeasts from a public collection ( Pichia guilliermondii , P. holstii , Wickerhamomyces anomalus ). The research was divided into two steps: a 1st step was aimed at assessing fungal growth by evaluating separately each factor; in a 2nd step, NaCl, pH and temperature were combined through a simple DoE (design of experiment). For this last step, W. anomalus and P. guilliermondii were used as test fungi. Generally, fungi were not inhibited either by temperature, salt or acidic/alkaline pH s. Moreover, the approach of DoE pinpointed that the effect of some factors could experience a shift and change over the time.