Publications des agents du Cirad


Understanding carotenoid losses in orange-fleshed sweet potato in drying and storage

Bechoff A., Tomlins K.I., Dhuique-Mayer C., Dufour D., Westby A.. 2009. In : 15th Triennal Symposium of the International Society for Tropical Root Crops (ISTRC). Tropical roots and tubers in a changing climate: A convement opportunity for the world, 2-6 November 2009, Lima, Peru. s.l. : s.n., 8 p.. Symposium of the International Society for Tropical Root Crops. 15, 2009-11-02/2009-11-06, Lima (Pérou).

Biofortified orange-fleshed sweet potato (OFSP) is being promoted to tackle vitamin A deficiency, a serious public health problem affecting children and pregnant/lactating women in sub-Saharan Africa. The aim of the study was to quantify and understand the factors influencing provitamin A losses in OFSP dried chips. Losses were determined after drying and storage. A preliminary pilot-scale study demonstrated that carotenoid levels were not significantly different after either solar or sun drying. Field conditions using locally-promoted varieties in Uganda and Mozambique showed losses associated with drying were less than 40%. Flour made from OFSP could therefore be a significant source of provitamin A. In contrast, storage of chips at room temperature in Uganda for four months resulted in high losses of pro-vitamin A (ca. 70% loss from the initial dried product). Low-cost pretreatments, such as blanching, antioxidants and salting, did not improve carotenoid retention during storage. To understand the cause of the losses, dried sweet potato chips were stored under controlled conditions of temperature (10; 20; 30; or 40ºC), aw (0.1; 0.3; 0.5 or 0.7) and oxygen (0 [under nitrogen]; 2.5; 10 or 21% [air]). Losses in provitamin A were the least during storage at the lowest temperature and oxygen level and at the highest humidity level. Enzymatic catabolism of [bêta]-carotene in the flour was considered unlikely because of low peroxidase activities at low water activities and the loss of peroxidase activity during storage.

Mots-clés : patate douce; ipomoea batatas; farine non céréalière; caroténoïde; mozambique; ouganda; provitamine a; chips

Documents associés

Communication de congrès

Agents Cirad, auteurs de cette publication :