Quantitative analysis of (-)hydroxy citric acid and (-)hydroxy citric acid lactone in Garcinia fruits and Garcinia products

A combined approach of titrimetry and HPLC for the detemination of (-) hydroxy citric acid (HCA), (-) hydroxy citric acid lactone (HCAL) and citric acid using selectively prepared samples of calcium hydroxycitrates with add without the corresponding lactone is described. The method consisted of determining total acids by titrating against standard alkali and citric acid by HPLC in a sample of calcium hydroxy citrate not containing lactone. From the difference in values, HCA contents were calulated. In a sample of calcium hydroxy citrate containing lactone, HCA contents were determined by HPLC. Similarly, HCA content were determined in a corresponding sample after total conversion of lactone to HCA. From the difference in values, HCAL contents were calculated. Thus, both HCA and HCAL standards could be prepared and used in experiments. Finally, HPLC method were employed in the determination of HCA, HCAL and citric acid in Garcinia fruit rinds and Garcinia products.