Application of natural and synthetic zeolites in the oenological field.

Zeolites are crystalline hydrated aluminosilicates, of natural or synthetic origin, characterized by a microporous structure and high adsorption properties. They are employed as soil amendments and fertilizer carriers in agriculture, as catalysts, detergents, adsorbents and molecular sieves in many chemical processes, as well as in water and soil decontamination, and in food processing. They have been also tested in the oenological field for several potential applications; yet an overview on such topic is not still available. The present review summarizes the recent and innovative applications of zeolites in winemaking and supplies a critical discussion about their potential to prevent protein haze, tartrate instability or the appearance of certain defects, like light-struck off-flavour and earthy off-flavours. Further applications of these minerals in the management of winery wastes and in the analytical field are also reviewed. The outcomes of this work evidenced the need of further research on the use of zeolites in oenology for better exploiting their peculiar sorption and exchange properties, selecting the most efficient natural types and improving the performances of the synthetic ones, without disregarding the potential secondary effects of these treatments on wine quality.