MICROBIOLOGICAL CHARACTERIZATION OF AGRESTO, A SEASONING WITH ANTIOXIDANT PROPERTIES FROM UNRIPE GRAPE

Agresto is a seasoning obtained from unripe grape used with vegetables, meat and food preparations to be improved by a sour note, which in this case is not due to the acetic acid but to other organic acids, mainly malic and tartaric. In Tuscany the interest of consumers stimulated the development of an experimental project to produce Agresto in the specific area of Amiata Mountain, with the aim of affirming the territorial specificities of a natural product derived from unripe grapes, obtained from local grapevine varieties, to enhance its use in gastronomy. The goal was to get to the production of a unique and genuine seasoning through natural methods and without preservatives, in order to obtain a final product from grapes cultivated by "organic farming", having sensory characteristics suitable for various types of dish combinations and showing a positive contribution to food beneficial properties. Sensory profiles obtained using the parametric sheet allowed describing its specific characteristics. Recently Agresto has been considered for its beneficial properties related to its origin from grape and to the method of production. The role of microorganism has been not considered of importance in Agresto production as it is made from cooked grape must, nevertheless in preliminary works microorganisms, mainly yeasts, have been detected in the final product and during the production phases. It suggests a possible microbial involvement on Agresto properties. In the present work chemical and microbial characterization of Agresto’s samples of different origins is discussed in relation with their antioxidant properties, antiradical activity, and total polyphenol content. Tuscan Agresto is currently marketed in very modest amounts especially in “short chain” as a niche product although its use could expand according with its potential as functional food.