Grape berries and vine leaves have a long history as traditional medicines in Europe and China. Red vine leaves are monographed in the French Pharmacopeia for medicinal use.
Some attribute the phenomenon of the "French Paradox" to consumption of red wine—at least to a certain degree. Although the French consume a diet high in saturated fatty acids, have high cholesterol levels, high blood pressure, and smoking rates similar to other countries, their incidence of death due to coronary heart disease is relatively low.

A European company now offers a red vine leaf extract containing the compounds believed to correspond to the healthy effects associated with the French Paradox. EFLA®945 Vitis vinifera Special Extract from Emil Flachsmann AG, Wadenswil, Switzerland, contains standard amounts of polyphenols, anthocyanins and trans-resveratrol.

The highest levels of anthocyanins are found in red vine leaves in the autumn, between the grape harvest and the time the leaves are shed from the vine. They are responsible for red and blue coloration of the leaves. Malvidin glucosides are the main anthocyanins in the leaves. Also occurring are delphinidin, cyanidin and pertunidin glucosides. Tannins from the catechin group are prominent in the leaves. The phytoalexin trans-resveratrol is a metabolite produced in response to UV light, fungal infection or physical injury, and also can be found in the red vine leaf.

Clinical Support

A clinical study affirmed the efficacy of red vine leaves for venous insufficiency. In this condition, legs feel tense, heavy, painful and cramped due to reduced elasticity of the veins, decreased efficiency of venous valves leading to insufficient return of venous blood from the legs. In vitro studies have demonstrated that phenolic compounds are effective antioxidants. They scavange free radicals and prevent the oxidation of LDL molecules. Trans-resveratrol particularly was found to inhibit aggregation of blood thrombocytes and contributed to a reduced formation of atherosclerotic plaque. Therefore, its antioxidative and anti-mutagenic properties may have a chemopreventive effect against disease.

Research has been conducted into the benefits of trans-resveratrol (trihydroxystilbene), including its ability to inhibit the oxidation of LDL cholesterol.
The Vitis vinifera red vine leaf extract is standardized to contain: polyphenols >30%, anthocyanins >0.3%, and trans-resveratrol>5mg/100g. The extract preparation has a pleasantly fruity flavor—with berry and black currant notes—and a slightly red color. The flavor harmonizes with sweet fruit flavors.

Possible food applications for the extract include soft drinks, dairy products and confections. The extract is water-soluble and can withstand the heat of food processing. In soft drinks, for example, the extract is stable at tunnel pasteurization or HTST conditions (72-95°C). It can be used at about 1.4g per liter in carbonated or still soft drinks. It is stable and clear in color at pH 2.8-4.5 in soft drinks. Examples of still drinks are bergamot-grape-passion fruit flavor beverage and instant iced teas with strawberry, elder blossom or other flowery flavors.

Dairy products that could contain the extract include yogurt, sour milk drinks, sorbets and fruit flavored ice creams. Use level in a strawberry yogurt could be 0.7g/kg. Confections include gumdrops, hard-boiled candies, toffees and cereal bars. It also can be used in baked goods.

The Vitis vinifera extract has not yet received any official classification, such as GRAS, in the U.S. However, the red vine leaf has been used as a foodstuff in Europe and the U.S. for many years, as in the Mediterranean appetizer stuffed grape leaves.

References:

Frankel EN, et al., 1993. Inhibition of human LDL oxidation by resveratrol. Lancet; 341:1103-1104
Jang M, et al., 1999. Cancer chemopreventive activity of resveratrol. Drugs Exp Clin Res; 25:65-77

For more information:

Susanne Fassler at +41 1 782 6464,
Fax: +41 1 782 6466
sales@flachsmann.chwww.flachsmann.ch.
Emil Flachsmann AG