The major functional composition in grape is grape polyphenol including proanthocyanidins. Besides, there are some other ingredients, like glucose, fructose, sucrose, xylose, tartaric acid, oxalic acid, citric acid, malic acid and single glucoside & glucobioside of all kinds of anthocyanidin.

2.1  Polyphenols

There are mainly 4 kinds of polyphenol substances in grape: tannin, anthocyanidin, phenolic acid and flavonoids. The vital polyphenols in grape is the same kind as flavonoids type, including flavane*3, *-diol, flavonoids tannin, flavonoids, flavonol, flavanol, chalcone and anthocyadin, etc. Anthocyanidins in grape are mainly as anthocyanin, methyle anthocyanin, petunidin, malvin and dephinidin, existing in common by dimmer or bigger molecule. The composition of flavonol kind in grape is major for quercetin in ordinary form. Proanthocyanidins are major ingredients in grape seed & grape skin, also the most kind in polyphenol content, mainly existing by dimer or polymer form.

2.2  Carbohydrate & total acid

Grape is abundant in sugar, which mainly as glucose and fructose; besides, with a little sucrose and xylose. Total acid is generally regarded as tartaric acid, additional with a little oxalic acid, citric acid and malic acid.

The antioxidant capacity of Grape Seed ( skin ) Extract comes from proanthocyanidins ( OPCs ). With an antioxidant power *0 times stronger than Vitamin C and *0 times stronger than Vitamin E, OPCs is known as a powerful antioxidant to neutralize free radicals, which play a major role in degenerative diseases, cardiovascular diseases, impaired vision, sun damage and premature aging. 

3.2  Cardiovascular Diseases

Researches have assured that OPCs helps strengthen capillaries, arteries and veins, which endows it several important clinical applications. OPCs appears to stabilize the walls of blood vessels, reduce inflammation, and generally support tissues containing collagen and elastin. OPCs not only can relieve or repair arteriosclerosis, but also relieve pain and oedema of venous insufficiency, through strengthening capillary and dropping permeability of capillary. Being effective against oedema that often follows injury or surgery, OPCs has been proved to effectively improve pathological changes in retina caused by diabetes, arteriosclerosis, inflammation and aging. For the same reason, it has been reported that OPCs can speed vision recovery after strong light, and improve vision acuity of those who suffer from eye fatigue due to long-time computer using.   

3.3  Skin Care