Impact of Traditional Food Processing Techniques on Mineral Bioaccessibility in Ghanaian Fermented Millet-Based Koko and Zoomkoom

Abstract

In this study, the impacts of traditional processing on phytates contents, phytate: mineral molar ratios, and the bioaccessibility of calcium, iron, and zinc in three traditional <i>koko</i> production units (KP1, KP2, and KP3) and two <i>zoomkoom</i> production units (ZP1 and ZP2) products were assessed based on the variations in their traditional processing techniques. The total calcium content of ZP1 was ranked the highest (58.02 mg/100 g, <i>p</i> < 0.05) compared to other processed samples. A high total value of iron (17.76 mg/100 g, <i>p</i> < 0.05) was revealed among <i>koko</i> compared to <i>zoomkoom</i>. Whereas KP3 and ZP2 showed the highest (<i>p</i> < 0.05) amount of zinc (3.34 mg/100 g). ZP1 showed a calcium bioaccessibility of 6.3% (<i>p</i> < 0.05). The iron bioaccessibility was within the average range of 5-30%, with KP1 ranking the highest (21.8%), while ZP1 showed the highest value (42.2%) (<i>p</i> < 0.05) in bioaccessibility of zinc among the <i>zoomkoom</i> products. The processing techniques adopted caused up to a 56.7% to 76.76% reduction (<i>p</i> < 0.05) of phytic acid in the pearl millet, leading to a decrease in the molar ratios of [Ca]:[Phy], [Fe]:[Phy], and [Phy]:[Zn]. However, the phytic acid content varied among the <i>koko</i> and <i>zoomkoom,</i> corresponding with the varied inhibitory mechanism indices reported. In brief, a positive correlation was shown between the traditional processing techniques, phytate, and in vitro bioaccessibility of minerals, indicating the consumption of <i>koko</i> and <i>zoomkoom</i> as a good source of functional minerals.