In 2019, 1,730 kilotonnes of wine grapes were crushed by the Australian wine industry, producing 350 kilotonnes of grape skins and seeds (grape marc) in the process. Indeed, CSIRO says grape marc is the biggest food-loss stream in Australian horticulture.
Our wine industry is keen to maintain its ‘clean, green’ image, and processing grape marc into high-value grape seed extract is ‘one of the most promising areas of waste valorisation’, states Fight Food Waste CRC in its summary of a new project.
The project’s initial aim is to turn 250 tonnes of marc from the 2020 vintage, predominantly Pinot grapes – the preferred source of grape seed extract – into ‘fully traceable Australian grape seed extract for export to Asia as a premium nutriceutical.
Grape seed extract (GSE), a dietary supplement, states the CRC, is ‘a highly sought-after ingredient in the Australian nutraceutical industry’.
It’s made by removing, drying and pulverising grape seeds, which are rich in antioxidants including phenolic acids, anthocyanins, flavonoids and oligomeric proanthocyanidin complexes (OPCs). GSE is one of the best-known sources of proanthocyanidins and, thanks to its high antioxidant content, can protect against oxidative stress, tissue damage, inflammation and skin ageing, preserving bone density and brain health.
Sources: Nutraceutical extraction from Australian wine industry waste I Fight Food Waste CRC; New benefits from wine-industry waste I Waste Management Review; 10 Benefits of Grape Seed Extract, Based on Science I Healthline