Minerals and antinutrients in fluted pumpkin (Telfairia occidentalis Hook f.)

Abstract

Abstract Studies were conducted to determine the biochemical composition of fluted pumpkin ( Telfairia occidentalis Hook f. ) at different stages of growth. Analyses were carried out at 12 and 50 weeks after planting on stems, leaves and roots, while seeds were analysed 8 and 32 weeks, respectively, after antethesis. Proximate moisture and carbohydrate content decreased in stems, leaves, roots and seeds with age, while ash, crude fibre and crude fat increased with age in stems, leaves, and roots but not in seeds. Elemental composition generally increased with age. In older stems, magnesium (50.5 mg/100 g) and calcium (40.5/100) were highest, while phosphorus (10.6 mg/100) and zinc (6.80 mg/100 g) were highest in older leaves compared to their younger ones. Young leaves, however, had highest magnesium (8.69 m/100 g) and iron (3.60 mg/100 g). Older seeds were richer in phosphorus (954 mg/100 g), potassium (632 mg/100 g) and iron (9.82 mg/100 g) while older roots had higher potassium (883 mg/100 g), calcium (150 mg/100 g) and magnesium (103 mg/100 g) than their younger counterparts. Young roots, however, had higher levels of iron (24 mg/100 g) and copper 2.24 mg/100 g). Antinutrients increased with age in the stems, roots and seeds. Young leaves, which are often preferred for human consumption, were higher in cyanide (60.1 mg/100 g.DM) and tannin content (40.6 mg/100 g DM) than older ones. Oxalate content (10.0 mg/100 gDM) and phytate content (48.8 mg/100 gDM) were higher in the older leaves than the younger ones. Some of the antinutrients in the leaves were above safety limits for human consumption. The authors suggest that young leaves be properly cooked in order to remove antinutrient effects before consumption. Old fluted pumpkin roots had very high levels of antinutrients: oxalate (2600 mg/100 gDM), cyanides (84.2 mg/100 gDM), tannins (60.1 mg/100 gDM) and phytates (84.4 mg/100 gDM) and may constitute potent human poisons. Younger pumpkin seeds may be nutritionally preferred for consumption since they contain less antinutrients than older seeds. However, mature pumpkin seeds contain high potassium, iron and crude fat (56.24%) and hence could be further developed to increase world vegetable oil production.