Table 5 Phytochemical composition of uncooked and cooked indigenous vegetables (mg/100 g)

Uziza leaf (Piper guineense)

Uncooked

0.96^d ± 0.02

0.22^f ± 0.03

0.34^f ± 0.01

1.19^d ± 0.03

0.83^d ± 0.02

Blanched

0.50^d ± 0.01

0.12^f ± 0.02

0.12^e ± 0.04

0.19^d ± 0.04

0.32^e ± 0.02

Sautéed

0.25^d ± 0.03

0.10^d ± 0.01

0.13^d ± 0.04

0.15^d ± 0.04

0.22^c ± 0.03

Nchuanwu (scent) leaf (Ocimum gratissimum)

Uncooked

0.72^e ± 0.01

4.09^a ± 0.02

0.64^e ± 0.03

0.24^f ± 0.05

0.13^e ± 0.03

Blanched

0.54^d ± 0.01

3.02^a ± 0.01

0.24^e ± 0.04

0.13^d ± 0.03

0.70^d ± 0.04

Sautéed

0.21^d ± 0.01

1.20^a ± 0.03

0.05^e ± 0.00

0.04^e ± 0.00

0.62^b ± 0.02

Anara (garden egg) leaf (Solanum melongena)

Uncooked

0.95^d ± 0.01

1.05^e ± 0.03

1.31^c ± 0.00

0.35^e ± 0.01

2.02^b ± 0.03

Blanched

0.21^e ± 0.00

0.58^e ± 0.01

0.91^b ± 0.01

0.04^e ± 0.03

1.32^b ± 0.04

Sautéed

0.06^e ± 0.02

0.02^e ± 0.01

0.42^b ± 0.01

0.01^e ± 0.00

0.22^c ± 0.01

Utazi leaf (Gongronema latifolium)

Uncooked

2.27^b ± 0.01

1.27^d ± 0.02

0.98^d ± 0.02

1.84^b ± 0.04

1.73^c ± 0.03

Blanched

2.03^b ± 0.02

0.82^d ± 0.01

0.45^d ± 0.01

0.57^c ± 0.01

0.89^c ± 0.21

Sautéed

0.83^b ± 0.02

0.32^b ± 0.01

0.22^c ± 0.01

0.21^c ± 0.02

0.61^b ± 0.01

Okazi leaf (Gnetum africanum)

Uncooked

2.02^c ± 0.01

1.81^c ± 0.01

1.77^b ± 0.01

1.32^c ± 0.03

0.19^e ± 0.02

Blanched

1.88^c ± 0.02

1.52^b ± 0.01

0.71^c ± 0.01

1.32^b ± 0.03

0.09^f ± 0.01

Sautéed

0.51^c ± 0.01

0.13^d ± 0.03

0.20^c ± 0.01

0.86^a ± 0.03

0.02^d ± 0.01

Onugbu (bitter) leaf (Vernonia amygdalina)

Uncooked

6.38^a ± 0.01

2.01^b ± 0.01

2.72^a ± 0.01

4.73^a ± 0.01

3.20^a ± 0.01

Blanched

3.11^a ± 0.01

1.21^c ± 0.01

1.07^a ± 0.03

2.40^a ± 0.01

1.88^a ± 0.02

Sautéed

0.98^a ± 0.01

0.26^c ± 0.01

0.52^a ± 0.01

0.64^b ± 0.01

0.82^a ± 0.02