ABSTRACT

The proximate, mineral, vitamin and phytochemical contents of orange fleshed sweet     potatoes (O), yellow fleshed sweet potato (Y), Beetroot (B), and carrot (C) were analysed. The samples analysed showed significant differences in their proximate composition, mineral, vitamin and phytochemical contents. The carbohydrate content decreased in the order O (32.37 %) > Y (29.71 %) > B (14.31 %) > C (9.26 %). The crude fibre decreased in the order Y (4.16 %) > B (3.82 %) > O (2.42 %) > C (1.61 %). The Fat content decreased in the order B (4.04 %) > C (2.97 %) > Y (1.54 %) > O (1.06 %). The protein content decreased in the order B (14.85 %) > C (10.51 %) > Y (4.82 %) > O (3.89 %). The ash content decreased in the order B (0.35 %) > C (0.26 %) > Y (0.05 %) > O (0.05 %). The moisture content decreased in the order C (3.54 %) > O (3.41 %) > B (3.21 %) > Y (2.88 %). The samples analyzed are rich sources of minerals (iron, zinc, copper, manganese, phosphorous, nitrogen, sodium, potassium, magnesium calcium and cobalt) that can be used to supplement daily requirements needed for physiological functioning necessary for life. The heavy metals such as nickel (0.01-0.02 ppm), lead (0.02-0.3 ppm) and cadmium (0.00-0.03 ppm) found in the samples were below the permissible limit. Thus, consumption of these samples as foods poses no immediate danger. The samples analyzed have shown to be rich sources of b-carotene (3.25-7.87 mg/100g), vitamin C (17.61-40.71 mg/100g), vitamin A (9.51-18.45 mg/100g), Riboflavin (0.08-0.38 mg/100g), niacin (0.77-2.24 mg/100g) and thiamine (0.11-0.15 mg/100g). Yellow fleshed sweet potato recorded the highest values for vitamin A, C and b-carotene. Carrot recorded the highest values for riboflavin and thiamine. The quantitative phytochemical screening of the samples revealed the presence of alkaloids, phenol, saponin, flavonoids, phytate, and tannin. Beetroot showed highest values for all the phytochemicals analysed. Except for phenol, orange and yellow fleshed potato recorded higher values for all the phytochemicals analysed than carrot. The result of this study showed that the samples analysed contained appreciable amount of essential nutrients and are safe for human consumption.