“…Most of these by-products are rich in polyphenols, stilbenes, flavonoids, which are natural antioxidants [30] widely used as additives able to positively affect the chemico-physical properties of polymers in alternative of synthetic stabilizers usually employed in plastics [31,32]. Besides phenolic compounds, the dry grape pomace may also contain simple carbohydrates, complex polysaccharides (especially pectins, up to 30 wt.%), lipids (up to 10 wt.%), proteins (less than 3 wt.%), carboxylic acids salts, in particular tartrates and malates which can be found in amounts as much as 5-7 wt.% [33,34].…”