Table 1.
Total anthocyanin content of fresh, frozen and freeze-dried strawberry puree measured by organic solvent and pH differential methods.
| Method Tested | Anthocyanin Concentration (A/gFW) | SD * |
| Clf-Methanol (Neff & Chory [7] (4) | 9.4 a | 0.7 |
| Methanol (Lindoo and Caldwell [6] (3) | 9.3 a | 0.6 |
| Clf-Methanol, Solovchenko et al. [5] (1) | 8.8 a | 2.0 |
| Methanol (Solovchenko et al. [5] (2) | 8.7 b | 1.5 |
| pH differential (Lee et al. [10] (5) | 6.5 c | 0.4 |
| Combined (Gauche et al. [11] (6) | 4.9 d | 1.0 |
| LSD | 0.5 | |
| Sample type | Anthocyanin concentration (A/gFW) | SD * |
| Freeze-dried | 8.6 a | 2.0 |
| Frozen | 7.9 b | 2.1 |
| Fresh | 7.9 b | 2.3 |
| LSD | 0.3 |
Abbreviations: * SD, standard deviation; A, absorbance; C3G, Cyanidin-3-glucoside used as internal standard, Superscript numbers in the brackets refer to the method number; Six methods were tested: (1) and (2) methanol method by Solovchenko et al. [5] with and without chloroform (Clf) respectively, (3) methanol method by Lindoo and Caldwell [6], (4) chloroform(Clf)-methanol method by Neff & Chory [7], (5) pH differential method by Lee et al. [10], and (6) combination of methanol and pH differential methods by Gauche et al. [11]. This formula (A530 − 0.3A657 × 20)/1 was used to calculate total anthocyanin content for methods 1 to 4 and ((A520 − A700)pH1 − (A520 − A700)pH4.5 × 20)/1 for pH differential and combined methods. Different letters in each column were significantly different at p ≤ 0.05.