Nutraceutical and antinutritional properties of wild edible plants consumed by pregnant women and school-age children (6-12 years) in Najjembe sub-county, Buikwe district, Uganda

Abstract

Wild edible plants (WEPs) immensely contribute to the diets and livelihoods of rural and marginalised communities. In rural Uganda, they play an important role as break tea packages for school-age children and due to their perceived nutraceutical significance, they are always added to the diets of pregnant women. In this study, it was hypothesised that Basella alba L. (Malabar spinach, Ceylon spinach, Indian spinach, Vine spinach, Malabar nightshade), Termitomyces microcarpus (Berk. & Broome) R. Heim (Cendawan Tali; Cendawan Taugeh) Cucurbita pepo L. (Courgette, Marrow, Pumpkin, Summer squash, Table queen squash, Vegetable Marrow, Zucchini) and Solanum anguivi L. (Forest bitter berry, African eggplant) have high nutraceutical significance and could contribute to the diets of school-age children and pregnant women. Using the standard Association of Official Analytical Chemists (AOAC) methods (method 935.14 and 992.24), the nutraceuticals and antinutrients in B. alba, T. microcarpus, C. pepo, and S. anguivi were investigated. All analyses and measurements were done in triplicate to increase the validity and reliability of the results. Solanum anguivi had the highest crude fibre (25.22±0.08 %), fat (6.55±0.05 %), and energy (371.37±1.17 Kcal) content. Termitomyces microcarpus had the highest protein (21.99±0.16 %) and moisture (10.71±0.35 %) content. Basella alba and C. pepo had the highest ash (19.39±0.01 %) and total carbohydrate (69.15±0.62 %) content. In comparison with the recommended dietary daily intakes for pregnant mothers and school-going children, all the plants had high Potassium, Phosphorous contents (except for T. Microcarpus which had low K contents), iron, copper, zinc, and manganese., but with selenium content being below the detection limit. All the analysed species were good in antioxidants, C. Pepo being the best with an IC50 of 11.78±0.47 mg/ mL followed by B. alba (14.69±0.74 mg/ mL). Solanum anguvi and T. microcarpus had the highest amount of phenols (14.48±0.02 mg/g GAE) and tannins (0.42±0.00 mg/g GAE). Basella alba had the highest amounts of flavonoids (2.45±0.01 mg/g RAE). All the plant species had low contents of phytates ranging from (0.40±0.01 for S. Anguivi to 0.72±0.08 for B. Alba). Cadmium and lead concentrations were below the permissible limit recommended by FAO/WHO Expert Committee in Food Additives. Thus, the analysed WEPs are a rich source of important nutrients and can be used to complement staple foods to ensure balanced nutrition for pregnant women and school-age children. Nonetheless, further comprehensive antinutrients and heavy metals analyses should be conducted to ensure that they do not affect the bioavailability of the nutrients. For value addition, nutrient-dense cocktails / phytonutraceuticals should be developed to alleviate malnutrition-related illnesses in vulnerable groups of people. Key words: Wild edible plants, Nutraceutical, Antinutrients, Heavy metals, Pregnant women, School-age children