Nutrient and anti-nutrient composition of durum, soft and red wheat landraces: Implications for nutrition and mineral bioavailability

Abstract

Morocco possesses a significant genetic diversity of wheat cultivars in the form of landraces conserved by local farmers in several regions. This study aimed to investigate the nutritional and antinutritional composition of 75 flour samples of durum, soft, and red wheat landraces cultivated in Morocco in order to determine their nutritional value. The analysis concerned the quantification of total carbohydrates, starch, lipid, fatty acids, protein, amino acids, minerals, and dietary fibers using AOAC standards, and phytic acid and polyphenols using spectrophotometric assays. The antiradical activity was evaluated using a DPPH assay based on the chelating properties of the free radicals against minerals. The bioavailability of minerals was also estimated using molar ratios. On a dry weight basis, soft wheat flour contains higher amounts of carbohydrates (80.307 ± 0.634 g/100 g), while durum (14.007 ± 0.569 g/100 g) and red (16.452 ± 0.141 g/100 g) wheat flours contain more proteins, predominantly represented by glutamic acid and leucine. The mineral analysis revealed the abundance of iron, zinc, and calcium in soft, red, and durum wheat flours. Concerning lipids, the flour samples showed relatively low concentrations with a distinct predominance of oleic, linoleic, and palmitic acids. The quantification of antinutrients revealed the richness of red wheat flour in dietary fibers (1.763 ± 0.103 g/100 g), total polyphenols (301.609 ± 0.169 μg GAE/g), and flavonoids (80.091 ± 0.121 μg QE/g), while durum and soft wheat flours contain more tannins (60.138 ± 0.751 μg CE/g) and phytic acid (9.182 ± 0.391 mg/g), respectively. The phenolic extract derived from red wheat flour demonstrated significant antiradical activity against DPPH, with an IC50 value of 121.683 ± 0.229 μg/mL. The calculated (PA:Fe), (PA:Zn), and (PA:Ca) were below the critical values, indicating a low bioavailability of iron, zinc, and calcium in the wheat flour samples. The results showed significant differences (p < 0.05) in the amounts of nutrients and antinutrients among the studied wheat cultivars, leading to variations in the bioavailability of their mineral contents. These quantitative differences could be used to more accurately guide dietary recommendations and develop focused strategies for optimizing the bioavailability of minerals in wheat flour-based products.