DETERMINAZIONE DELL’IMPRONTA CARBONICA DEI SOTTOPRODOTTI DELLA VINIFICAZIONE E LORO VALENZA BIOLOGICA

Abstract

The wine sector from economical and productive point of view is a very important agri-food branch and it can reach a key role in reduction of carbon dioxide emission through re-use of its waste, turning them into by-products. To do that it is important to find for them an added value. Winemaking process produces pomace and seeds, lees and stalks. In this study we want to estimate, at national level, the ecological impact of these by-products. In Italy wine is one of the main agri-food sectors with the production, during 2016 vintage, of about 51 million hectolitres of wine. The vineyard area covers 5.2% of farming land and it is widespread all over the Italian regions. From an environmental point of view it must be taken into account that each hectolitre of wine will produce a considerable amount of by-products. Although there are several factors involved in the estimation of this amount, such as variety, winemaking process, type of pressing, climatic and environmental factors, it is possible to drawn up a proper assessment at national level. In fact, the National Agency for Environmental Protection (2001) estimated that for every hectolitre of wine produced can be calculated an average of 6 kg of lees, 18 kg of pomace and 4kg of stalks. There are several models, at national and international level, to evaluate the ecological footprint, in the various productive branches. Nowadays reached great interest the use of Life Cycle Assessment (LCA), methods that considers the environmental impact throughout the whole product’s lifecycle. In the present work, on the base of the 2016 wine production, using the “International Wine Calculatr” calculation tool, CO2eq production has been estimated for by-products (lees, pomace and stalks). The results show that, were produced 278,000 t, 834,000 t and 185,000 t of CO2eq respectively for lees, pomace and stalks. These substrates are still an important source of nutrients: pomace, consisting of skins and seeds, are a source of polyphenols with strong antioxidant power. Lees, mainly composed by dead yeasts, are an important source of β-glucans. For the purpose of showing the production phases of these by-products, in this paper is illustrated a standard winemaking process for a red berry grape and an analytical determination of the quantity of biomolecules extracted from by-products.