Sustainable extraction of functional compounds from vine shoots and their food application

Vine shoots represent a vineyard waste generated by pruning, with a production estimated per year of about 1–2 tons per hectare, generally used as a heating source or soil conditioner. The valorization of vine shoots has been focused over the production of ethanol and paper pulp, however using this raw material as a source of functional compounds for food application would increase its economic value. Vine shoots were shown to be an important source of polyphenols and oligosaccharides. The interest in prebiotic oligosaccharides and polyphenols as functional ingredients has gained attention due to their ability to benefit human health. Xylo-oligosaccharides (XOs) are formed by xylose units linked through β-1,4 glycosidic bonds and they could present arabinosyl, acetyl, uronic or phenolic groups as substituents. The main objective of this work was to apply a green technology, the steam explosion, to obtain an extract enriched in XOs and polyphenols to be added in a functional spreadable goat cheese. After the characterization of sugar profile and polyphenols, the extract was added to the cheese throughout a kneading phase with the aim to reach a minimum quantity of 3g of oligosaccharides per 100 g of cheese. The obtained cheese, after pasteurization, was subjected to the determination of the physico-chemical, textural, sensory and volatile aroma compounds characteristics. Overall, the investigation allowed to develop a prototype enriched in XOs and polyphenols by upcycling vine shoots.