polyphenols

Accelerated stability studies of Emblica officinalis, Terminalia belerica and Terminalia chebula have been carried out as per ICH guidelines and its effect on total polyphenol content as determined by Folin-Ciocalteu method and Gallic acid content as determined by HPLC (High Performance Liquid Chromatography) was studied. The samples were kept in stability chamber at 40°C and 75% relative humidity for 3 months for accelerated stability studies. Samples were taken out at periodic intervals and extracted to determine total polyphenol content by spectrophotometric method and gallic acid content by HPLC. The HPLC method was also validated to demonstrate its selectivity, linearity, precision, and accuracy. The results indicate an increase in total polyphenolic content as well gallic acid content under accelerated stability conditions which is indicative of hydrolysis of gallotannic acids present in crude drugs to liberate free gallic acid, thereby increasing the total polyphenolic content.

The present study revealed that, acetone among pure forms of experimental solvents and Ethyl acetate + Methanol + Water among the mixture forms could extract significantly higher (p

The changes in polyphenols and caffeine alkaloid compositions of black tea, due to the variations of fermentation temperature were investigated. Black tea was manufactured by fermentation at various temperatures such as 26oC (Control) 30o, 36o and 40o where the tea leaves were fermented initially for 45-50 minutes at an private factory. During this oxidation process, withered and rolled leaf looses its green colour acquiring copper red to brown colour. Drying terminates these biochemical changes and remove moisture thereby the colour of fermented leaves turns from copper red to black and fermentation is arrested. Total polyphenols content were determined colorimetrically using Folin-Ciocalteau method and caffeine was isolated from all the samples by Liquid-Liquid extraction using chloroform. The results showed that increase in fermentation temperature significantly increases caffeine content whereas polyphenols content showed a great reduction at 30o, 36o and 40o. However further studies are needed to evaluate the organoleptic characters such as taste and aroma.