Özet:

The aim of this research was to investigate and compare the nutritional, antinutritional, and phytochemical composition of two varieties (TME 9 (olekan–aga) and TME 7 (oko–iyawo)) of Manihot esculenta (cassava) tubers at different ages (6 months and 12months). The result of proximate analyses showed that 12-month-old samples of both varieties had higher moisture contents (44.3±0.24, 44.7±0.47) compared to the 6-month-old samples (34.8±0.62, 37.5±0.71). A 12-month-old sample of TME 7 had the lowest ash and protein contents of 1.33±0.24 and 2.28±0.21 respectively with highest carbohydrate contents of 90.38±0.7 among the four samples analyzed. The result of mineral analysis revealed that the predominant mineral is Ca (1,209.5, 1,273.3, 1,276.8 and 1,178.5 mg/kg) for the 6-month-old TME 9, 12-month-old TME 9, 6-month-old TME 7 and 12-month-old TME 7 respectively), followed by Na, Fe, and Mg in that order. Quantitative phytochemical analysis showed that the 12-month-old samples have the largest quantity of alkaloids and saponins (16.03±1.70, 21.44±0.56 mg/100 g and 4.41±0.31, 3.54±0.25 mg/100 g respectively) for both varieties compared with 11.69±0.43, 12.49±0.53 mg/100 g and 2.39±0.23, 1.84±0.12 mg/100 g recorded for the 6-month-old samples of both varieties. Flavonoids and tannin contents are lower in the 12-month-old samples (2.1±0.64, 2.07±0.34 mg/100 g and 0.14±0.03 and 0.13±0.04 mg/100 g) compared with the 6-month-old samples with 3.5±0.57, 3.73±0.19 mg/100 g and 0.22±0.05, 0.21±0.02 mg/100 g respectively. Antinutrient contents - oxalates, cyanogenic glycosides and phytates are high for both species at 12 months while the 6-month-old samples recorded the lowest content. The results suggest that the 6-month-old samples are more desirable in terms of higher nutrient contents (especially carbohydrate and energy) as well as lower antinutrient contents.

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