Separation and characterisation of chlorogenic acid-rich conserves from green coffee beans and their radical scavenging potential

P>Methanolic extract (Me-1) obtained from low-grade green coffee beans (LCB), which is one of the major by-products in the coffee industry, was enriched with phenolics by different methods viz., partitioning in solvents, chromatographic separation using dowex & diaion HP20 resins and precipitation by lead acetate. Separated fractions and Me-1 were analysed for total polyphenol, chlorogenic acid, caffeine and radical scavenging activity (RSA). Chlorogenic acid isomers of Me-1 and the isolated fractions were analysed by HPLC. Me-1 found to contain total polyphenol (16.60 +/- 0.4%), chlorogenic acids (CGAs) (29.60 +/- 0.9%), caffeine (7.52 +/- 0.2%) and exhibited RSA (92.50%) at 100 ppm concentration. Precipitation method resulted significantly (P < 0.05) higher phenolics (46.33 +/- 0.5%) as well as CGAs (43.50 +/- 0.7%). HPLC analysis indicated that the composition of 5-Caffeoylquinic acid (5-CQA) was more in all the isolated fractions.