Table 3.
Flavonoid and 3-deoxyanthocyanidin composition of raw white rice, cowpea, sorghum leaves, their composite blend, and cooked products.
| Sample | Raw Rice | Raw Cowpea | Raw Leaves | Raw Mix | Boiled Rice | Cooked Rice–Cowpea Blend | Total |
|---|---|---|---|---|---|---|---|
| Soluble free flavonoids and anthocyanins | |||||||
| Catechin O-glucoside | nd | 328.9 ± 14.9 c | nd | 168.7 ± 6.2 b | nd | 57.3 ± 1.1 a | 554.9 ± 7.7 C |
| Procyanidin B1 | nd | 156.4 ± 0.9 c | nd | 70.2 ± 4.0 b | nd | 43.4 ± 0.9 a | 270.0 ± 4.1 B |
| (Epi)-afzelechin O-glucoside | nd | 255.9 ± 31.1 c | nd | 61.2 ± 5.5 a | nd | 105.9 ± 15.1 b | 422.9 ± 36.4 BC |
| Quercetin dihexoside | nd | 7.9 ± 0.2 c | nd | 3.8 ± 0.1 b | nd | 2.4 ± 0.2 a | 14.1 ± 0.4 A |
| Quercetin hexoside | nd | 16.4 ± 0.5 b | nd | nd | nd | 6.5 ± 0.3 a | 22.9 ± 0.5 A |
| Naringenin | nd | nd | 403.5 ± 4.1 b | 9.6 ± 0.2 a | nd | nd | 413.1 ± 4.1 BC |
| Luteolinidin | nd | nd | 3340.8 ± 308.0 b | 15.3 ± 0.1 a | nd | nd | 3356.1 ± 308.2 F |
| Eriodictyol | nd | nd | 2163.5 ± 171.9 c | 12.4 ± 0.3 b | nd | 5.4 ± 0.0 a | 2181.3 ± 171.6 E |
| Apigeninidin | nd | nd | 71,881.9 ± 351.6 c | 299.5 ± 2.7 b | nd | 3.4 ± 0.1 a | 72,184.8 ± 352.8 H |
| Luteolin | nd | nd | 1077.5 ± 36.2 b | 5.2 ± 0.2 a | nd | 1.5 ± 0.1 a | 1084.2 ± 36.1 D |
| Apigenin | nd | nd | 3630.3 ± 27.8 c | 17.7 ± 0.1 b | nd | 4.3 ± 0.4 a | 3652.3 ± 27.8 G |
| Total | nd | 765.5 ± 18.4 C | 82,497.6 ± 494.9 D | 663.6 ± 15.2 B | nd | 230.1 ± 5.2 A | |
Key: Results are presented as means ± standard deviation of triplicates. “nd” means not detected. Catechin O-glucoside and (epi)afzelechin O-glucoside were expressed as catechin equivalents. Quercetin dihexoside and quercetin hexoside were expressed as quercetin equivalents. Luteolinidin, apigeninidin, eriodictyol, naringenin, luteolin, and apigenin were expressed as naringin equivalents. Units of all measurements are expressed as µg/g sample, dry weight basis. Values in a row with different superscript letters were significantly (p < 0.0001) different from each other. Significant differences among means of measured variables are shown by lowercase superscripts, while significant differences among means of total values are denoted by uppercase superscripts.