Comparative Studies on the Phytochemicals, Nutrients and Antinutrients Content of Cassava Varieties

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.