Retention and storage stability of beta-carotene in dehydrated drumstick leaves (Moringa oleifera)

Drumstick leaves (Moringa oleifera) procured from home gardens were shade dried after steam blanching or after steam blanching followed by sulphiting in 0.2% potassium metabisulphite solution and were stored in polythene containers having double lids for three months. The samples were analyzed for total carotene, betacarotene and ascorbic acid in the fresh form, immediately after drying and on 30, 60 and 90 days of storage. Analysis of fresh leaves revealed that they contained 27.1 mg of total carotene, 17.4 mg of beta-carotene, and 143.6 mg of ascorbic acid per 100 g. Sulphiting in addition to blanching was more effective in the retention of beta-carotene immediately after dehydration (72% vs. 59%) and at the end of one month of storage (64% vs. 51%) but not at the end of 90 days of storage (53% vs. 47%). The shade-dried drumstick leaves when rehydrated and incorporated into recipes suffered further losses of beta-carotene, which were smaller in recipes that involved steaming and shallow frying (27% and 31%) but greater in recipes that involved repeated bailing and stirring (65%). All recipes were rated as highly acceptable and two of them per one serving provided the full RDA for pre-school children. Thus dehydrated drumstick leaves have the potential to serve as a valuable source of beta-carotene in the diets of the population in India and other developing countries.