The UK wine industry is growing. Climate change is resulting in a rapid expansion of English and Welsh vineyards, and this expansion is predicted to continue over the coming decades. Although this will generate significant opportunity, wine production comes with a challenge – large amounts of grape waste are generated. William Sullivan, biochemical researcher working at the University of Kent, has a vision to turn this nutrient rich waste into new foods with health benefits.

In the United Kingdom there are currently 4,400 hectares of vines planted, and WineGB projects a further 3,200 hectares will be planted by 2032. Even after this projected planting an additional 26,100 hectares of land are estimated to be suitable for vines in the UK, and with warmer temperatures resulting from climate change the wine industry in the UK is expected to continue to expand over the coming decades.

The UK experienced the fastest growth in vineyard area out of major wine producing countries at 6% in 2023, and the greatest increase in wine produced at 77%. These increases are being driven by both domestic operators and overseas winehouses purchasing land in the UK as a hedge against climate change.

In 2022 9,336 tonnes of grapes were produced for wine, resulting in 12.2 million bottles of wine. However, this also produced a large amount of solid waste. Being 584 tonnes of grape stems, and 2,344 tonnes of grape pomace. Alongside vine prunings from the maintenance of the vines. 

Waste resulting from wine production is only going to increase given the rapid expansion of the viticulture industry in the UK. Currently the valuable, beneficial compounds within grape waste aren’t being extracted, and are going to waste.

There are health benefits linked to the consumption of red wine, such as a lower risk of dementia, and increased cardiovascular health. These benefits derive from the action of a class of polyphenolic compounds called ‘proanthocyanidins’, which are present in red wine. 

Procyanidins inhibit the synthesis of the signalling molecule endothelin-1, meaning endothelin-1 isn’t binding to endothelin receptors. The activation of endothelin receptors lead to vasoconstriction, resulting in an increase in blood pressure. This means that due to the action of the proanthocyanidins the endothelin receptors aren’t being activated, causing blood pressure to remain lower overall. Resulting in the aforementioned health benefits.

Grape pomace is rich in polyphenols, which are strong antioxidants. Antioxidants can reduce the risk of certain types of cancer. This is by antioxidants scavenging free radicals, preventing the free radicals from causing DNA damage. Antioxidants are also implicated in lowering risk of heart disease, as well as promoting digestion, by supporting beneficial constituents of the gut microbiome.

By consuming products derived from grape pomace the health benefits of the polyphenolic compounds can be received, without the detrimental health impacts linked to consuming alcohol.

Currently grape pomace is often composted on site being spread locally, sent away for industrial composting or anaerobic digestion, both of which cause the producer to incur transport costs. All three of these options waste the valuable health benefitting compounds present in the grape pomace.

Some wineries such as Lympstone Manor in Devon, use a small amount of their grape pomace to flavour gin. Grape waste is also now being used in some cosmetics, because of its antioxidant properties due to the high polyphenol content.

Westwell Vineyard is providing grape pomace to the cosmetics company Pelegrims. Pelegrims is producing cosmetics enriched with polyphenols which have been extracted from the waste grape pomace, valorising the waste into a component of a marketable product.

The aim of my project is to contribute to the development of new food products, made from viticulture waste which will have a positive effect on the health and lifespan of humans.

In the bioscience labs at the University of Kent, based in Canterbury, I am conducting research into the potential health benefits of compounds present in grape pomace. This is being carried out using the model organism C. elegans, which is a nematode worm, with 83% of its proteome (complete set of proteins expressed by an organism) having homologous genes in humans.


C. elegans, a nematode worm

I have been collaborating with Defined Wine and NIAB to source grape pomace, and I have samples of Pinot Noir, Pinot Noir Précoce, Pinot Meunier and Divico, from the 2023 and 2024 harvests.

I am also using gut models to investigate the effect of grape pomace on the gut microbiome, and how the polyphenolic compounds in the grape pomace are metabolised, and how the metabolites impact the gut microbiome.

Alongside the biochemistry aspect of my project, I am also investigating the potential uptake of methods for the valorisation of grape pomace waste by the viticulture industry. And measuring consumer desire for a product such as cereal bars fortified with extracts of grape pomace, or the inclusion of grape pomace extracts in smoothies or protein shakes and to identify potential price points of such a product.

I would greatly appreciate it if you would take a few minutes to fill in my survey regarding your grape pomace waste, and your willingness to allow this waste to produce a value-added product.

The purpose of this survey is to identify what is currently being done with the grape pomace waste, and whether there is interest in the industry to valorise the waste, or if alternative uses have already been considered. As well as if the industry sees the potential valorisation of their waste as something which could potentially add value to their brand or pique the interest of consumers.

The aim of this survey is to form part of a report which will be able to help guide the industry towards economically and environmentally positive valorisation solutions for viticulture waste, which would be beneficial for the viticulture industry as well as consumers.

To take part in the survey visit https://universityofkent.qualtrics.com/jfe/form/SV_bfv1wqTq2ReUCZo


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