Upcycled beauty study: Wine waste enriches skincare with antioxidant compounds

18 Jul 2022 --- A study conducted by researchers from Lebanon and Italy found that organic grape waste from winemaking has rich antioxidant phenolic compounds suitable for use in skincare products.

Grape seeds are agro-industrial byproducts that, if not managed properly, can cause socioeconomic and environmental issues.

However, they can be effectively valorized by extracting the bioactive components, particularly the antioxidant phenolic molecules, utilizing a safe and environmentally friendly extractive medium – hydro-glyceric solution.

This study supports the incorporation of phenolic extracts into commercial creams to enrich the cosmetic industry with natural and safe skincare products.

Slashing the sludge
High amounts of organic waste consisting of grape pomaces, lees, stalks and dewatered sludge are created throughout the winemaking process, which primarily consists of grape pressing and maceration. These byproducts are either composted, fed to animals, or disposed of in landfills.

However, one of the main environmental hazards connected with these residues is their low pH and high concentration of phenolic chemicals, which are resistant to biological degradation.

The researchers note that grape pomaces have a high organic carbon content (31 to 54%), which causes water pollution and terrible aromas; also, pests and tannins, among other chemicals, may harm neighboring flora and fauna. They have attempted to identify the optimum extraction process capable of collecting these components from the waste.

Winemaking leaves chemically rich grapeseed byproducts that are either composted, fed to animals or disposed of in landfills.Favorable phenolic applications
These phenolic compounds have promising applications, particularly in the beauty area. The compounds can be utilized instead of synthetic ones to create effective, safe and natural products that meet modern society’s needs.

The antioxidant, antifungal and antibacterial activities of grape polyphenols are the most important benefits.

As a result, they are now employed in cosmetics, particularly anti-aging and skin lightening treatments, because they can improve skin moisture and smoothness, reducing roughness, wrinkle depth, skin redness and hyperpigmentation.

Additionally, polyphenols can protect the skin from oxidative stress and ultraviolet damage, acting as photoprotection with a high sun protection factor.

They are capable of inhibiting the activity of proteinase, collagenase and elastase – which are responsible for the degradation of collagen and elastin – thus ensuring skin firmness and elasticity.

Testing the extracts' stability
This study aimed to analyze and characterize the extracts derived from different grape seed kinds (Marselan, Syrah, Obeidi, Cabernet Franc, and Asswad Karech), and to construct antioxidant and natural cosmetic formulations employing the more efficient extract obtained, solely from natural ingredients.

The phytocomplexes were extracted using a simple and scalable process involving a mixture of water and glycerin as an extractive solution because the latter is less erosive to the skin than ethanol.

Three batches of creams containing six creams each (5%, 4%, 3%, 2%, 0% of the Marselan hydro-glyceric extract, and 5% of a commercially purchased extract) were prepared and stored at three different temperatures (4, 25, 50°C) for the stability tests.

Total phenolic and proanthocyanidin content, as well as antioxidant activity, were determined. Grapeseed extracts can improve skin moisture, reduce roughness, wrinkle depth, skin redness and hyperpigmentation.

After centrifugation and heat-shock cycles, the extracts were incorporated into natural-based creams. Their stability was assessed by measuring pH, viscosity and physicochemical composition. The developed formulations may, therefore, serve as an economic booster to the local cosmetic market.

Results fit for retail
Overall results confirmed that the cream containing 5% of Marselan type of grape extract had the highest phenolic content and antioxidant activity. All of the creams were more stable at 4°C and less stable at 50°C, irrespective of the concentration of extract.

Furthermore, all the stability tests including pH, viscosity, total phenolic content, and antioxidant activity, were extended for more than eight months and it was proven that all creams remained stable.

The performed studies confirmed that the maceration of grape seed pomace in a hydro-glyceric mixture is an easy and environmentally-friendly method to obtain a promising extract.

The extract obtained from the Marselan variety had the highest phenolic content and antioxidant activity followed by that from Syrah, Obeidi, Cabernet Franc and Asswad Karech. Moreover, the extract from Obeidi has proven to have a significant antioxidant potential when compared to the others.

Furthermore, Marselan extract can be efficiently added to a commercial cream at increasing quantities of up to 5% without compromising its physicochemical qualities or stability. The creams containing Marselan extract were stable when stored for four months and exhibited high antioxidant activity, paving the way for the creation of commercial skincare formulations.

By Mieke Meintjes

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