Mineral, phenolic and anthocyanin profile in flours of grape pomace: effects of diferent winemaking process

Abstract

Wine industry is an important economic activity in the World, generating significant quantities of residues, mostly known as grape pomace. This material is rich in many nutrients, as fiber, minerals and antioxidants substances, such as phenolic compounds. These nutraceutical properties of grape pomace could be harnessed for human or animal consumption. In this context, a trial was carried out aiming to study the effects of maceration in winemaking on the composition of grape pomace flours. The grape pomace was obtained in a commercial winery located in the North of Santa Catarina State, Brazil, from the cultivars Pinot Noir, Malbec, Tannat and Ancellotta, sampled before or after maceration process. All the pomace flours were obtained by dehydration process in a drying oven. The following analysis were performed: Total polyphenols content, total anthocyanins and mineral content (N, P, K, S, Ca, Fe, Mg, Mn and Zn). Flours of grape pomace that was submitted to maceration process in the winery had higher minerals content for all grape cultivars, with emphasis on iron (168.8 – 286.5 mg 100g^-1) and calcium (357.0 – 429.5 mg 100g^-1). Nevertheless, flours of grape pomace not submitted to maceration process presented lower content of antioxidant substances. For anthocyanins, no macerated samples presented higher content for the cultivars Pinot Noir (18.4 mg 100g^-1), Tannat (88.6 mg 100g^-1) and Ancellotta (94.2 mg 100g^-1). In relation to total phenolic composts, no macerated samples were higher for the cultivars Pinot Noir (8.1 g 100g^-1) and Tannat (4.3 g 100g^-1).