Proximate, Mineral and Antinutrient Compositions of Indigenous Okra (Abelmoschus esculentus) Pod Accessions: Implications for Mineral Bioavailability

Abstract

The promotion and consumption of indigenous vegetables could help to mitigate food insecurity and alleviate malnutrition in developing countries. The proximate, mineral and antinutrient compositions of eight accessions of Okra Pods were investigated. Molar ratios and mineral bioavailability of Okra pod accessions were also calculated and compared to the critical values to predict the implications for mineral bioavailability. Proximate and mineral composition of Okra pod accessions were determined using standard methods of Association of Official Analytical Chemists. The result of the study revealed that the proximate composition (g/100 g) in dry weight basis was significantly (P<0.05) varied and ranged : moisture/dry matter 9.69-13.33, crude protein 10.25-26.16, crude fat 0.56-2.49, crude fiber 11.97-29.93, crude ash 5.37-11.30, utilizable carbohydrate 56.42-69.92 and gross energy 257.50-319.39 kcal/100 g. The mineral concentrations (mg/100 g) were also significantly (P<0.05) varied and ranged: calcium (111.11 to 311.95), Iron (18.30 to 36.68), potassium (122.59 to 318.20), zinc (3.83 to 6.31), phosphorus (25.62 to 59.72) and sodium (3.33 to 8.31) on dry weight bases. The Okra Pods of 'OPA#6' accession contained significantly higher amounts of crude protein, total ash, crude fat, gross energy, calcium, iron and zinc than all other accessions evaluated in this study. The results of anti-nutrients analysis showed that, except phytate, the tannin and oxalate contents of all the accessions were significantly (P<0.05) varied. The range of phytate, tannin and Ooxalate contents (mg/100 g) for Okra pod accessions studied were: 0.83 to 0.87, 4.93 to 9.90, 0.04 to 0.53, respectively. The calculated molar ratios of phytate: calcium, phytate: iron, phytate: zinc, oxalate: calcium and [Phytate][Calcium]/[Zinc] were below the critical value and this indicate that the bioavailability of Calcium, Iron and Zinc in these accessions could be high. The results of the study generally revealed that Okra pod contain appreciable amount of vital nutrients like protein, fibre, calcium, Iron and zinc and low in antinutrient contents with high mineral bioavailability. Therefore, increase the production and consumption of these nutrient rich indigenous Okra pods will help to supplement/ formulate the diets and alleviate the problems associated with malnutrition in the country.