Development of an Innovative Controlled Drying Technology for the Recovery of Waste from the Wine Chain from a Circular Economy Perspective

The circular economy model applied to the wine industry is linked to the enhancement of waste from wine production, which is represented by grape leaves and grape pomace. Recent studies have described these waste products as rich in antioxidant and antimicrobial bioactive molecules, such as anthocyanins, flavonoids, procyanidins, and other polyphenolic derivatives. The presence of these molecules allows the recovery of waste from the wine chain to obtain semifinished and finished products applicable in different sectors. This work involved the development of an innovative soft and controlled drying technology, which was applied to grape skin and seeds through the use of a chamber characterized by the control of the process parameters, in particular temperature, humidity, ventilation, drying time, and sanitization with ozone and/or UVC radiation, to maintain the biological properties of the unaltered plant matrix. The ability of this process to preserve the content of active molecules of Vitis vinifera L. was indeed demonstrated by HPLC-DAD-MS characterizations and Folin-Ciocalteu spectrophotometric assays. The dried grape skin and seeds were subjected to controlled micronization to obtain innovative functional products for use in green agriculture, cosmetics, food, nutraceutical, and wine making, allowing them to respond to circular viticulture and industrial symbiosis models.