Table 5.
Polyphenol fractions and anti-radical activity of 6 wheat genotypes fertilized by two nitrogen levels (High and Low). Means are followed by standard error (n = 4).
| Soluble Polyphenols | Hydrolysable Polyphenols | Total Polyphenols | Bio-Accessible Polyphenols | Anti-Radical Activity † | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
| N Level | Genotypes | mg Gallic Acid/100 g Flour | % of Total Polyphenols | mg Gallic Acid/100 g Flour | % of Total Polyphenols | mg Gallic Acid/100 g Flour | mg Gallic Acid/100 g Flour | % of Total Polyphenols | Remaining µmol DPPH at Steady State | % |
| High N | Genotype 18 (HYG) | 224 b ± 6.77 | 19 | 928 a ± 33.66 | 81 | 1152 a ± 31.00 | 540 abc ± 13.13 | 47 | 0.220 c ± 0.004 | 55 |
| Genotype 6 (HYG) | 172 c ± 6.12 | 19 | 719 b ± 27.31 | 81 | 892 b ± 26.86 | 586 a ± 21.91 | 66 | 0.212 c ± 0.006 | 57 | |
| Genotype 10 (HYG) | 200 bc ± 8.25 | 21 | 745 b ± 30.83 | 79 | 949 b ± 41.17 | 552 ab ± 20.74 | 58 | 0.215 c ± 0.003 | 56 | |
| Genotype 3 (LYG) | 294 a ± 9.68 | 24 | 924 a ± 35.81 | 76 | 1218 a ± 36.94 | 575 ab ± 14.59 | 47 | 0.206 c ± 0.009 | 58 | |
| Genotype 9 (LYG) | 265 a ± 17.90 | 23 | 905 a ± 85.29 | 78 | 1159 a ± 80.31 | 531 bc ± 23.40 | 46 | 0.257 b ± 0.006 | 48 | |
| Genotype 16 (LYG) | 205 bc ± 17.08 | 18 | 924 a ± 52.25 | 82 | 1129 a ± 45.49 | 494 c ± 13.87 | 44 | 0.278 a ± 0.009 | 44 | |
| Low N | Genotype 18 (HYG) | 297 ab ± 19.29 | 32 | 619 a ± 40.72 | 68 | 916 a ± 20.35 | 543 cd ± 9.33 | 59 | 0.248 a ± 0.002 | 50 |
| Genotype 6 (HYG) | 297 a ± 14.89 | 34 | 573 a ± 25.42 | 66 | 873 ab ± 17.10 | 517 d ± 21.13 | 59 | 0.243 ab ± 0.005 | 51 | |
| Genotype 10 (HYG) | 293 a ± 12.58 | 34 | 559 a ± 36.03 | 66 | 851 ab ± 51.15 | 541 cd ± 14.89 | 64 | 0.253 a ± 0.011 | 49 | |
| Genotype 3 (LYG) | 284 ab ± 12.52 | 32 | 602 a ± 50.13 | 68 | 886 ab ± 45.07 | 601 ab ± 14.89 | 68 | 0.206 c ± 0.009 | 58 | |
| Genotype 9 (LYG) | 255 b ± 5.55 | 29 | 622 a ± 51.08 | 71 | 876 ab ± 52.72 | 647 a ± 18.43 | 74 | 0.219 c ± 0.006 | 56 | |
| Genotype 16 (LYG) | 263 ab ± 5.48 | 33 | 525 a ± 23.87 | 67 | 788 b ± 23.38 | 587 bc ± 21.87 | 74 | 0.223 bc ± 0.010 | 55 | |
| N effect (%) | −19.36 *** | +47.03 *** | +25.21 *** | −4.62 * | ns | |||||
| Two-way ANOVA | ||||||||||
| p-value (G effect) | <0.001 | 0.01 | <0.001 | 0.02 | <0.001 | |||||
| p-value (T effect) | <0.001 | <0.001 | <0.001 | 0.01 | 0.91 | |||||
| p-value (G × T) | <0.001 | 0.06 | 0.002 | <0.001 | <0.001 | |||||
Within each treatment, letters indicate significant differences between genotypes at p < 0.5. * and *** are significant at p < 0.05 and p < 0.001, respectively. ‘ns’ means insignificant difference at p < 0.05. Values in bold indicate significance (p < 0.05). † corresponding to 2.4 mg flour or 2.4–2.6 mg bread at flour basis that consumed DPPH when 0.494 µmol of the free radical are initially available to react. The plateau was decided at 120 min of reaction. HYG: High-yielding genotypes (grey shadowed), LYG: Low-yielding genotypes.