Assessment of the fining efficiency of zeins extracted from commercial corn gluten and sensory analysis of the treated wine

The aims of the present work are to evaluate zeins as potential clarification agent for red wine and to assess the impact of zeins treatment on the wine “bouquet” through sensory analysis. Zeins have been extracted from commercial corn gluten which is a protein-rich by-product deriving from maize starch industry. Three red wines (cv. Cabernet Sauvignon, Merlot and Valpolicella) have been used for the fining experiments in order to test zein proteins (Z) in comparison with a commercial nonhydrolysed animal gelatins (G1). The new method of zeins extraction gave a good yield of extraction (about 72%). These proteins showed an excellent fining action if compared to wine treatment with G1. In fact, zeins treatment could decrease wine turbidity and remove phenolic compounds, such as anthocyanins and proanthocyanidins, and, at the same time, it did not affect red wine colour. Finally, the sensory analysis indicated that no significant differences were detected between the same wines clarified with Z or with G1. In conclusion, the results show that corn gluten can be used in place of potentially allergenic animal proteins to obtain a low cost fining agent that can be introduced during the wine clarification step.