Tartaric acid grape skin extract

Grape skin extract (enocianina) is a purplish red liquid prepared by the aqueous extraction (steeping) of the fresh deseeded marc remaining after grapes have been pressed to produce grape juice or wine. It contains the common components of grape juice namely, anthocyanins, tartaric acid, tannins, sugars, minerals, etc, but not in the same proportions... 

In addition to anthocyanins, grape skin extract contains plant acids (mainly tartaric acid), tannins, sugars, amino acids, minerals. 

Fruit compresses have been applied to the face as beauty aids for millennia. The alpha-hydroxy acids contained in fruit extracts, tartaric acid in grapes, citric acid in citrus fruits, malic acid in apples, mandelic acid in almond blossoms and apricots are thought to be active principles for skin rejuvenation. Such alpha-hydroxy acids do stimulate HA production in cultured dermal fibroblasts (unpubl. exp.). The results of such alkaline preparations may depend more on their peeling effects rather than on the ability of alpha-hydroxy acids to stimulate HA deposition. 

The principle of the method consists of rapidly extracting the anthocyanins from the skins, gently at first and then under more extreme conditions, where the diffusion barriers are broken down. Acidity is used as a vector to facilitate extraction. In addition, it is recommended that the grapes should be roughly crushed and the resulting flesh diluted by half. Crushing the seeds also results in partial extraction of their tannins, which is necessary to assess the characteristics of the grapes. The solutions are aqueous, pH 1 (HCl n/10) and pH 3.2 (solution with 5 g/1 tartaric acid neutralized by 1/3). 

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