Resveratrol is a natural polyphenolic compound belonging to the group called stillbene. It has medicinal functions which include anti-cancer, anti-oxidation, prevention of cardiovascular diseases. Red and green grapes (Vitis vinifera) berry skins and flesh were analyzed for trans-resveratrol using HPTLC and UV scanner. Both types of grapes’ skin showed small but significant amount of resveratrol. Different types of grape samples were measured and macerated with 99,9% methanol acidified with 0.1% HCl for 24hrs at 30 ᵒC in the dark. Sample application and HPTLC densitometric scanning were done using HPTLC mechines on to 10cm x 10cm HPTLC plates. The wavelength for detection was evaluated from complete UV spectrum of resveratrol, 313nm. 25.7g of fresh green grape skin was observed that it contained approximately 0.363mg of trans-resveratrol. 20.0g of dried red grape skin contained approximately 0.802mg of transresveratrol. Fresh red and green grape flesh showed no presence of trans-resveratrol and also fresh red grape skin. The (retardation factor) Rf of resveratrol was obtained 0.34. Estimation of resveratrol in the samples was done by taking proportional comparison of area under the curve of the grape extract samples' peaks and resveratrol's peak at the Rf value of 0.34. However, all grape extract showed predominating peaks at Rf of 0.11. Green grape berry skin was considered to be containing much of the trans-resveratrol as compared to red grape berry skin and grape berry flesh of all the two types. Peaks at Rf value of 0.11 were probably of metabolites of trans-resveratrol or any other compound in the samples. Despite the observed small amount in some samples, it seems to be the metabolites of trans-resveratrol or other compound predominating in all the samples .Therefore, since the trans- isomer is affected much by UV and heat, the compound might have deteriorated during the sell or storage of the grapes
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The validation densitogram