Indigenous food processing methods that improve zinc absorption and bioavailability of plant diets consumed by the Kenyan population

Abstract

Zinc deficiency is a public health problem associated with pregnancy complications and birth outcomes, impaired immune function, and increased duration and severity of diarrhea in children. Zinc is an essential trace mineral that is a component of over 200 enzymes and is known to be necessary for normal collagen synthesis, mineralization of bones, and is also involved in vital processes such as mitosis, synthesis of DNA and protein, and gene expression and activation. In many low-income countries diets are composed primarily of cereals and legumes which contain phytate that inhibit zinc absorption. Most Kenyan diets are composed of cereals and legumes that have high content of zinc inhibitors, whose levels may be reduced through appropriate food processing technologies at the household level. Indigenous food processing methods like soaking, germination, drying, fermentation, boiling, and roasting, and diet combinations usually reduce the levels of zinc antagonists in the plant diets, thus increasing zinc absorption and bio-availability. These methods are used in combination to both enhance organoleptic properties of food, increasing acceptability and also promoting complementation of nutrients. There are food combination patterns that enhance nutrient bioavailability and complementation that was known to most traditional households and are quickly being forgotten due to changing lifestyles, food preparation methods and food tastes. This is worsened by lack of proper knowledge transfer from the older generation. However, the transfer of indigenous knowledge in food processing, preparation and diet combinations need to be profiled to identify processes that promote nutrient content and bioavailability for improved health and nutrient situation of rural populations whose diets are basically plant based. There is need to identify suitable sources of absorbable zinc and possible suitable dietary combinations that can contribute towards the reduction of zinc deficiency. This paper discusses the indigenous food processing methods that enhance zinc absorption and bioavailability of zinc in local dietary combinations that could reduce zinc deficiency. Keywords: Zinc, soaking, germination, drying, fermentation. AJFAND Vol. 9 (1) 2009: pp. 524-535