Multifunctional prebiotic found in chardonnay grape pomace

The leftovers from chardonnay wine production have yielded a new whole food prebiotic ingredient whose rich suite of bioactives comes as something of a surprise — considering the constituents of red wine varieties garner the most attention. 

The ingredient, dubbed WellVine, was born out of an effort to find uses for the large amount of grape pomace leftover from wine production. It was the brainchild of two women — Barbara Banke and Peggy Furth — associated with Jackson Family Wineries and Kellogg’s, respectively. Jackson Family Wines has brands and vineyards around the globe. 

Huge untapped resource 

These women were keenly aware that the family business generated thousands of tons of waste that traditionally had gone to low-value uses, such as animal feed additions. By one measure, the California wine industry crushes more than 600,000 tons of chardonnay grapes annually, producing pomace at about the rate of 1 kilogram for every 6 liters of wine produced. An effort was undertaken to fully characterize the pomace to unlock whatever hidden value it might contain. 

Like many ingredients in the food and supplement space, it was the story of an overnight success that took years. In 2009, a subsidiary called Sonomaceuticals was founded to house the effort. 

The ingredient was highlighted in a session at the Probiota Americas 2024 meeting in Salt Lake City, which concluded Wednesday, June 12. The ingredient garnered an award at a 2023 iteration of the event, which was held in Milan, Italy. 

Several different methods are employed when grapes are crushed to liberate the juice for winemaking. In the case of red wine grapes, the material is macerated and allowed to age briefly, before the juice is siphoned off. A slight amount of fermentation takes place at this stage. 

In the case of white wines, the harvested grapes are rapidly pressed to separate the juice, leaving an unfermented pomace in the wake. Like red wine pomace, this consists of skins, seeds and a bit of leftover pulp. In both styles of wine, the principal fermentation takes place in the casks after the juice is separated. 

Small processing difference led to big implications 

That tiny bit of fermentation proved to be a key differentiator in the process, said Scott Forsberg, the company’s chief operating officer. When starting the discovery process about what health-promoting ingredients might be extracted from the pomace, the company contracted with the U.S. Department of Agriculture to do the chemical analysis and safety studies. 

Forsberg said the initial expectation was that the red wine pomace would have superior activity. In 2009, the industry was still in the heady days of excitement over resveratrol and the French Paradox — the popular assertion that red wine consumption was responsible for the relative health of the French population, even when they were eating significant amounts of saturated fat in the form of cheeses and various meats. 

But, Forsberg said, early USDA assays revealed something quite different. Among the ways the various pomaces were tested was via feeding studies to lab animals. 

“Not only were the animals not getting sick, but they were also doing better than the animals on the standard chow,” Forsberg told Natural Products Insider during an interview in Salt Lake City. “They saw things like improved glycemic response and less fat accumulation in the liver.” 

The chardonnay pomace far outperformed the others. 

“That shocked us,” Forsberg said. 

The fact that the chardonnay pomace had not undergone any fermentation meant its constituents were still mostly in their native forms, he added. 

Complex chemistry yields broad, durable effects 

To further understand the complex nature of the raw material, Forsberg said the company teamed with a group of researchers at the University of California, Davis, led by Professor Daniela Barile, Ph.D. 

Their paper, which was published in the Journal of Agricultural Food Chemistry, fully characterized the complex makeup of the whole ingredient. The raw material proved to be rich in oligosaccharides, flavonoids, flavanols and other fractions. Barile outlined the results during the Probiota event. 

The degree of polymerization of the oligosaccharides put them right in the sweet spot to feed beneficial intestinal flora, he said. Further in vitro research showed a number of beneficial species could digest the material, while the ingredient did not foster the growth of harmful bacteria. 

“It was good for the good bugs, but none of the bad bugs could use the material,” he said. “It was sort of like spraying weed and feed on your lawn.” 

Forsberg said the particularly attractive feature of the ingredient is its rich complexity, even though that complicates telling the story of exactly which fraction is doing what. Many competing prebiotics on the market, by contrast, are simple in their makeup or are in fact single-molecule entities. 

“That feels like you are back to eating a highly processed food,” he said. “With our ingredient, we are encouraging the growth of a commensal community within the gut.” 

Better-for-you chocolate? 

The dried ingredient proved to have a neutral, lightly sour wine-like flavor. Forsberg, who was first trained as a microbiologist, attributed the flavor to the organic acid content. The additional pleasant surprise was the ingredient acted as a flavor modifier when included in potentially bitter food matrices like chocolate. The company passed out chocolate samples at the Salt Lake City event, which were smallish discs. Each contained a full 4.5-gram dose of the ingredient but tasted like premium chocolate. 

Forsberg said the effect was so pronounced the company invested into obtaining a patent on it.