Table 4. Concentration of specific polyphenols (mean ± standard error) in strawberry fruit from organic (ORG) and conventional (CON) farms (n = 13).
| Polyphenol (mg 100 g−1 FW) | ‘Diamante’ | ‘Lanai’ | ‘San Juan’ | P Value | |||
| ORG | CON | ORG | CON | ORG | CON | ||
| April | |||||||
| Quercetin glycoside | 4.00±1.38 | 6.72*±1.38 | 9.18†±1.41 | 5.43±1.41 | 9.01±1.56 | 7.60±1.56 | 0.009 |
| Quercetin, total | 7.02±1.17 | 9.45*±1.17 | 11.71†±1.17 | 7.92±1.17 | 11.22±1.56 | 10.11±1.56 | 0.020 |
| Kaempferol | 0.93±0.08 | 1.13†±0.08 | 0.99±0.08 | 1.05±0.08 | 1.28*±0.10 | 1.07±0.10 | 0.026 |
| June | |||||||
| Quercetin glycoside | 6.27±1.17 | 7.20±1.17 | 2.87±1.41 | 6.09*±1.41 | 5.01±1.28 | 5.32±1.28 | 0.009 |
| Quercetin, total | 8.78±1.14 | 9.72±1.14 | 6.42±1.17 | 8.80*±1.17 | 7.92±1.15 | 7.81±1.15 | 0.020 |
| Kaempferol | 1.21‡±0.07 | 0.96±0.07 | 0.98±0.08 | 1.03±0.08 | 1.06±0.07 | 0.98±0.07 | 0.026 |
| September | |||||||
| Quercetin glycoside | 4.97±1.17 | 4.87±1.17 | 3.89±1.41 | 3.93±1.41 | 4.90±1.28 | 7.13*±1.28 | 0.009 |
| Quercetin, total | 7.51±1.14 | 7.33±1.14 | 6.61±1.17 | 6.57±1.17 | 7.37±1.15 | 9.19±1.15 | 0.020 |
| Kaempferol | 0.96±0.07 | 0.92±0.07 | 1.03±0.08 | 1.05±0.08 | 0.93±0.07 | 1.00±0.07 | 0.026 |
| ORG | CON | ||||||
| Quercetin | 2.79±0.06 | 2.71±0.06 | 0.17 | ||||
| Kaempferol glycoside | 4.28±0.97 | 4.34±0.97 | 0.88 | ||||
| Kaempferol, total | 5.32±1.02 | 5.35±1.02 | 0.93 | ||||
| Ellagic acid glycoside | 55.0±13.1 | 53.8±13.1 | 0.92 | ||||
| Ellagic acid | 2.27±1.48 | 2.08±1.48 | 0.70 | ||||
| Ellagic acid, total | 57.2±1.31 | 55.9±1.31 | 0.88 | ||||
| Phloridzin glycoside | 2.04±0.29 | 2.24±0.29 | 0.49 | ||||
| Phloretin | 2.40±0.04 | 2.43±0.04 | 0.56 | ||||
| Phloretin, total | 4.42±0.31 | 4.64±0.31 | 0.41 | ||||
| R-Naringin glycoside | 2.90±0.95 | 1.35±0.95 | 0.27 | ||||
| S-Naringin glycoside | 2.90±0.98 | 1.46±0.98 | 0.32 | ||||
| R-Naringenin | 0.43±0.07 | 0.44±0.07 | 0.83 | ||||
| S-Naringenin | 0.24±0.07 | 0.29±0.07 | 0.51 | ||||
| R-Naringenin, total | 3.31±0.95 | 1.77±0.95 | 0.28 | ||||
| S-Naringenin, total | 3.12±0.98 | 1.73±0.98 | 0.34 | ||||
Fruit were sampled in June and September 2004 and April, June, and September 2005 from 13 pairs of organic (ORG) and conventional (CON) farm fields. Least square means ± standard error of the means. Probabilities (P values) for treatment x variety x month interactions for quercetin glycoside, total quercetin, and kaempferol, and for treatment main effects for the remaining polyphenols are given. Means and standard errors of specific polyphenol concentrations for individual sampling/harvest times, varieties, and years are listed in Tables S4A–E.
*Means are notably different at P<0.10.
†
Means are significantly different at P<0.05.
‡
Means are significantly different at P<0.01.