Antioxidant compounds from coffee silverskin

CSIC has developed and patented a procedure for the extraction of antioxidant compounds from coffee silverskin, a residue of roasted coffee beans. The extracts obtained contain high amounts of bioactive compounds such as chlorogenic acid and caffeine, with applications in cosmetics, food and health. Industrial partners interested in the development and commercialization of this technology, are sought.

Coffee seeds, variety Coffea Canephora - Robusta. C.Barbedo. Wikipedia CommonsThe procedure consists on the extraction of the coffee silverskin (the only by-product of coffee roasting) without prior milling, by using subcritical water at moderate temperature (50ºC or higher) and high pressure (1500 psi). Nevertheless, unpressurized water at 100ºC can be used too.

Under these conditions, extracts with high antioxidant properties are obtained in 10-20 minutes, with antioxidant activity depending on the extraction conditions.

Using only hot water, it can be obtained 0.85 grams of equivalents of chlorogenic acid and 150 milligrams of caffeine. Using subcritical water, the results improve: 3,7 grams of equivalents of chlorogenic acid and 450 mg of caffeine, both per 100 mg of silverskin.

Chlorogenic acid is a natural compound found in plants, which has an essential role in their response to stress. It has antioxidant and anti-inflammatory properties, according to some studies.

The extracts, following lyophilisation, are stable at room temperature for more than 6 months, making them highly suitable for its use as antioxidants. Moreover, experiments “in vitro” have shown that they keep its antioxidant activity after gastrointestinal digestion. This broadens its potential applications as functional ingredients, as the components can survive gastrointestinal digestion process and remain bioavailable.

The process enables the exploitation of a by-product of coffee beans processing, widely available and which disposal is an environmental problem.

Finally, the extract can be used directly as a cosmetic ingredient, either as an excipient (preservative, flavouring) or as an active element (antioxidant, anti-cellulite), facilitating a pH closer to the skin.

The process enables the exploitation of a by-product of industrial processing of coffee beans, widely available and which disposal is an environmental problem.  It is an environmental friendly, low-cost method that avoids using organic solvents. It saves, also, energy and time, since it is applied to the whole coffee silverskin without previous grinding. Therefore, the extraction is more effective, as caking occurring with silverskin powder is avoided.


Débora Villaño (This email address is being protected from spambots. You need JavaScript enabled to view it.)
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