Uncorking the benefits of red wine waste for food colouring

Of the 2 million tonnes of wine grapes crushed annually in Australia, about 20% by weight remain as waste after processing. The majority of this winemaking waste, which includes skins, seeds and stalks, is currently returned to the land as compost, or other low-value applications.

Now, chemical engineers at Monash University have found that this waste from winemaking could be upcycled as a valuable source of ingredients for nutraceuticals, pharmaceuticals and food colouring. It could also have potential uses as functional ingredients in non-alcoholic beverages in the future.

PhD student Xueqing (Rachel) Liu and Associate Professor Victoria Haritos, Monash University Department of Chemical and Biological Engineering, found that compounds derived from red wine grape varieties have significant levels of bioactive natural compounds called polyphenols and anthocyanins.

Anthocyanins, the pigments responsible for the colours red, purple and blue in many fruits and vegetables, have also been associated with antioxidant effects. Both polyphenols and anthocyanins have also been associated with some health benefits.

“Bioactive polyphenols and anthocyanins could have a number of commercial applications as functional ingredients, in dietary supplements and as natural food colourings,” Liu explained.

The initial research, published in the international journal Cleaner Waste Systems, was supported by Treasury Wine Estates in collaboration with Coldstream Hills Winery in Victoria’s Yarra Valley where the winemaking samples were gathered.

In the next phase of the research, Liu will further investigate processes for extracting the bioactive compounds and their potential uses including functional non-alcoholic beverages.

Image credit: iStock.com/RapidEye