Food-to-food fortification of a traditional pearl millet gruel with a natural source of β-carotene (sweet potato) improves the bioaccessibility of iron and zinc

Iron and zinc deficiencies are still a public health concern in the Far North region of Cameroon where staple foods are mainly cereals containing appreciable amounts of minerals, but also inhibitors of their intestinal absorption. In this work, the effect of food-to-food fortification of a traditional pearl millet gruel with a natural source of β-carotene on the bioaccessibility of iron and zinc was assessed. A sensory evaluation of a gruel fortified at 20, 30 and 40% with mashed sweet potato were first carried out. Then the studied samples were analysed for carotenoids, polyphenols, phytates, iron and zinc contents using spectrophotometric methods. Bioaccessible iron and zinc were evaluated through a simulated in vitro digestion technique. The results showed that fortified gruels were more appreciated than the control (p˂0.05). Carotenoids, phytates and polyphenols were higher in fortified gruels (p˂0.05) while iron and zinc were lower. A maximum increase (p˂0.05) in the bioaccessibility of both iron and zinc was observed in the gruel fortified at 20 and 30%. By improving the bioaccessibility of iron and zinc, food-to-food fortification of pearl millet gruels with mashed sweet potato could contribute to alleviate these minerals deficiencies in the Far North region of Cameroon.