The wine industry generates 20 million tons of by-products annually, corresponding to about 30% of the total quantity of vinified grapes. Healthy bioactive molecules (e.g. polyphenols) are abundantly present in these by-products. This opens up a promising avenue for nutritional foodstuff production in the future.
A recent Antioxidants article reviewed the various health benefits and food industry applications of the by-products of the wine industry.
Grape pomace (GP) and wine lees are the key waste streams with food interest. GP is composed of stems, skins, and seeds and is a great source of phenolic compounds. The liquid phase is also rich in ethanol and organic acids. Wine lees also have important biological and antioxidant properties.
Given the high nutritional value of wine by-products, these compounds should be reused in the food industry and for the enrichment of products consumed in the Mediterranean diet (MD). MD is low in consumption of animal products and is mainly a plant-based diet. It further has low greenhouse gas emissions and a small environmental impact. The usage of by-products, such as polyphenols from GP, has the dual benefit of being good for human health and also being environmentally friendly.
Applications in the food industry
Wine by-products have good taste and attractive color, facilitating their use in developing novel food products with plenty of health benefits. The new food products could also be substitutes for traditional synthetic additives.
Vine roots, leaves, and seeds have been widely used as food preservatives and flavoring agents. In some cultures, they are also part of traditional medicine. The high polyphenol component is responsible for the antioxidant, antimicrobial, anticancer, and anti-inflammatory effects. These compounds can also be extracted from wine by-products and applied in the food industry to ensure product safety, augment shelf life and prevent microbial spoilage.
The addition of GP powder to substitute flour during the process of wheat bread fortification has enhanced the physical properties and bioactive potential of pasta and bread. In the case of fortified waters and infusions, the bioactivity of GP has also been evaluated.
In the context of dairy products, GP has served as a coagulant in the production of tofu and reduced the fat content of cheese. More widely, wine by-products have served as a source of functional compounds in the formulation of yogurts, ice creams, and fermented milk, among other products.
Research has shown that adding GP powder to biscuits increases the protein content and decreases free fatty acids. GP is an essential source of fiber and polyphenols, and adding GP could be an alternative to gluten-free products. Concerning non-alcoholic and alcoholic beverages, limited studies are available regarding the role of wine by-products. Still, recently, GP extracts have been used to produce a functional coconut beverage. Despite the controversial health impact of beer, it has been shown that beers with white GP have greater concentrations of phenolic compounds and antioxidant properties. Additionally, these beers also possess lower amounts of a toxic compound, namely, acetaldehyde.
Several in vitro, in vivo, and clinical studies have documented the health benefits of enriching food with the by-products of the wine industry. More specifically, research has shown that food products with wine by-products or extracts exhibited anti-inflammatory, cardioprotective, antioxidant, and anticancer properties.
The ability of wine by-products to modulate the inflammatory process and scavenge free radicals has been shown in pre-clinical studies. This is achieved through the inhibition of the key inflammatory mediator, NFκB. Proinflammatory enzymes, such as MAPK, COX-2, and protein kinase-C, are also inhibited.
Wine by-products increase anti-inflammatory cytokines and have a mitigating effect on inflammatory cytokines. Food products with these compounds hold enormous promise in preventing chronic diseases. It is essential to understand the molecular mechanism of action, the nature of wine by-product compounds, and their suitable combinations to elicit bioactivity. More epidemiological, pre-clinical, and follow-up studies are needed to explore the maximum nutraceutical potential of wine by-products.
Implementing sustainable practices is rare, despite scientists, winemakers, and politicians speaking about sustainability. The usage of wine by-products is a golden opportunity to enrich food and reap economic, social, and environmental benefits. The current study argued that the producers and the scientific community must look for profitable and sustainable options by maximizing the utilizing of by-products and minimizing the disposal of waste flow.
The management of wineries must embrace the recovery and recycling of valuable ingredients and the production of new products. The goal of this review article is to bring together all relevant participants and inspire them to develop real commercialized applications.
Ferrer-Gallego, R. and Silva, P. (2022) The Wine Industry By-Products: Applications for Food Industry and Health Benefits. Antioxidants. doi: https://doi.org/10.3390/antiox11102025 https://www.mdpi.com/2076-3921/11/10/2025