Low Jan W, van Jaarsveld Paul J
International Potato Center, Regional Office for Sub-Saharan Africa, Nairobi, Kenya.
Food Nutr Bull. 2008 Jun;29(2):98-107. doi: 10.1177/156482650802900203.
Orange-fleshed sweet potato is an efficacious source of vitamin A. Substituting wheat flour with orange-fleshed sweet potato in processed products could reduce foreign exchange outlays, create new markets for producers, and result in increased vitamin A consumption among consumers provided there is adequate retention of beta-carotene during processing.
To explore whether substituting 38% of wheat flour (by weight) in bread buns ("golden bread") with boiled and mashed orange-fleshed sweet potato from fresh roots or rehydrated chips would produce economically viable beta-carotene-rich products acceptable to Mozambican rural consumers.
Modified local recipes maximized sweet potato content within the limits of consumer acceptability. Sensitivity analysis determined parameters underlying economic viability. Two samples each of buns from five varieties of orange-fleshed sweet potato were analyzed for beta-carotene content. Processed products with at least 15 microg/g product of trans-beta-carotene were considered good sources of vitamin A.
Golden bread made from fresh roots of medium-intensity orange-fleshed sweet potato varieties met the good source criterion, but bread from lighter-intensity sweet potato varieties did not. Bread from rehydrated dried chips was not economically viable. Consumers strongly preferred golden bread over pure wheat flour bread because of its heavier texture and attractive appearance. The ratio of the price of wheat flour to that of raw sweet potato root varied from 3.1 to 3.5 among the bakers, whose increase in profit margins ranged from 54% to 92%.
Golden bread is a good source of beta-carotene and is economically viable when the price ratio of wheat flour to raw orange-fleshed sweet potato root is at least 1.5. Widespread adoption during sweet potato harvesting periods is feasible; year-round availability requires storage.
橙色肉甜薯是维生素A的有效来源。在加工产品中用橙色肉甜薯替代小麦粉可以减少外汇支出,为生产者创造新市场,并在加工过程中β-胡萝卜素得到充分保留的情况下,增加消费者对维生素A的摄入量。
探讨用新鲜块根或复水薯片煮制并捣碎的橙色肉甜薯替代面包(“黄金面包”)中38%(按重量计)的小麦粉,是否能生产出莫桑比克农村消费者可接受的、经济上可行的富含β-胡萝卜素的产品。
改良当地食谱,在消费者可接受的范围内最大限度地增加甜薯含量。敏感性分析确定了经济可行性的潜在参数。对五个橙色肉甜薯品种的面包各取两个样本分析β-胡萝卜素含量。每克产品中反式β-胡萝卜素含量至少为15微克的加工产品被视为维生素A的良好来源。
用中等橙色强度的橙色肉甜薯品种的新鲜块根制成的黄金面包符合良好来源标准,但颜色较浅的甜薯品种制成的面包不符合。用复水干薯片制成的面包在经济上不可行。由于其质地更重、外观更吸引人,消费者强烈偏好黄金面包而非纯小麦粉面包。面包师中小麦粉与未加工甜薯块根的价格比在3.1至3.5之间,他们的利润率提高了54%至92%。
当小麦粉与未加工橙色肉甜薯块根的价格比至少为1.5时,黄金面包是β-胡萝卜素的良好来源且在经济上可行。在甜薯收获期广泛采用是可行的;全年供应则需要储存。