Studies on identification of white specks in cured aonla (Emblica officinalis Gaertn.) fruits

Aonla (Emblica officinalis Gaertn.), an Indian vitamin C-rich fruit, has great potential for pickling but the development of white specks during curing and pickling is a major hindrance. Studies to evaluate the effects of various pre-treatments on the development of white specks were carried out. The extent of white specks was less in aonla fruit segments preserved in steeping solution containing 10% salt and 0.04% KMS than in those preserved by dry, salting with 10% salt and 0.02% KMS during one month of storage. The fruits which developed white specks were poor in texture and brownish in colour. These white specks were isolated and extracted with water. The white specks thus obtained were purified as white solid matter. This was insoluble in water and other common organic solvents but soluble in alkali solutions. The IR and ‘H NMR spectra and mp confirmed that the white solid matter isolated and purified from white specks of preserved fruits was mucic acid (d-galactaric acid). Its mineral analysis indicated the formation of some unknown complex of this compound with calcium and potassium.