Grape pomace: from wine residue to functional and healthy ingredient

After making wine, tons of grape skins, seeds, and stems remain. For years, they have been wasted, but science has recognized their potential. This byproduct is called grape pomace, and it is proving to be a true nutritional gem: rich in antioxidants, fiber, minerals, and essential fatty acids.

Illustration of three bunches of different types of grapes.

A recent study conducted by teams from Argentina and Italy analyzed two types of grape pomace: that of Isabella wine (Vino de la Costa, Argentina) and that of the classic Cabernet Sauvignon (Italy). They discovered that both have enormous potential as functional ingredients.

What is grape pomace?

Grape pomace is everything that remains after pressing grapes to make wine: the skin, seeds, some bits of pulp, and stems.

This byproduct represents up to 30% of the total weight of the grape, and although it is sometimes discarded or used as fertilizer, it contains valuable bioactive compounds that could be used in human nutrition.

Nutrients and Benefits: What's Hidden in Wine Residue

Some of the nutrients hidden in grape pomace are:

Fiber for the intestine.

  • Pomace contains between 57 and 65 grams of fiber per 100 g, mostly insoluble.
  • Ideal for improving intestinal transit and helping achieve the recommended 30 g daily intake.

Vegetable Protein

  • It contains around 12% protein, making it an interesting choice for foods rich in non-animal protein.

Essential Minerals

  • Potassium, calcium, iron, zinc, phosphorus, magnesium, among others.
  • Cabernet stood out for its higher levels of calcium (more than 6,000 mg/kg), potassium, and zinc.

Healthy Fatty Acids

  • Isabella pomace contains more unsaturated fats, such as linolenic acid (omega-3).
  • Having better lipid profiles leads to a lower cardiovascular risk.

Natural Antioxidants

  • Very high polyphenol content (flavonoids, anthocyanins, resveratrol).
  • Isabella pomace was the big winner in this regard: up to three times more antioxidants than Cabernet Sauvignon.

How can it be used?

Pomace can be dried, milled, and used as flour to:

  • Enrich breads, muffins, and cookies with fiber and antioxidants.
  • Improve the nutritional profile of gluten-free foods.
  • Create functional snacks, energy bars, or natural supplements.

In previous studies, it has even been used in plant-based burgers, pasta, and breakfast products with positive sensory results.

Beyond Nutrition: Sustainability

The use of grape pomace also reduces waste and closes the wine production cycle:

  • Less pollution, due to the avoidance of organic waste accumulation that could otherwise ferment or generate emissions if not properly managed.
  • Greater value for small producers, as they get 100% of the product, even utilizing what was previously considered "waste."
  • It contributes to the circular economy, as it transforms an agricultural byproduct into a functional ingredient, reintroducing it into the food chain with new nutritional and commercial value.
Two bunches of grapes hanging from a vine

And what does science say?

To evaluate the potential of grape pomace as a functional ingredient, researchers analyzed its chemical and bioactive composition in detail. They studied samples of two varieties: Isabella pomace (from the Vino de la Costa wine in Argentina) and Cabernet Sauvignon pomace (Italy), to compare their nutritional and functional properties.

Several key aspects were measured:

  • Overall nutritional composition, including protein, fiber, lipids, and essential minerals such as calcium, potassium, zinc, and iron.
  • Fatty acid profile, with special attention to the balance between saturated and unsaturated fats and its relationship to cardiovascular risk.
  • Presence of polyphenols and antioxidant capacity, using widely validated methods such as Folin-Ciocalteu, FRAP, and DPPH, which allow the quantification and comparison of the effectiveness of these compounds in neutralizing free radicals.

The results were very revealing:

  • Isabella pomace showed a higher concentration of phenolic compounds (especially flavonoids and phenolic acids) and significantly higher antioxidant activity. Furthermore, it presented a better lipid profile, with a higher proportion of polyunsaturated fatty acids, which are beneficial for cardiovascular health.
  • Cabernet pomace, on the other hand, stood out for its higher mineral content, especially calcium and zinc, as well as its higher amount of dietary fiber, making it interesting for formulations focused on digestive health and the enrichment of fiber-rich functional foods.

Both grape pomaces, therefore, have complementary characteristics. This suggests that their use can be adapted to different purposes within the food industry: from improving the nutritional profile of breads or flours to designing antioxidant supplements or functional products with specific benefits.

Conclusion

What was once waste could now be a functional ingredient that strengthens your health. Grape pomace is not only a source of fiber and antioxidants, it's also a smart way to reuse what was previously thrown away.

Because nature is wise, and science must observe and listen to it in order to continue proposing conscious solutions.

Illustration of a bunch of black grapes

Written by Sara Montaner. We rely on AI technology.

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