Table 2.
The accuracy and recovery of the FCM method for the rapid quantification of astaxanthin and the Car/Chl ratio.
| No. | 1 | 2 | 3 | 4 | 5 | Mean Value | |
|---|---|---|---|---|---|---|---|
| Sample 1 | MFI in FL2 (a.u.) | 7914 | 8056 | 8301 | 8233 | 8117 | 8124 ± 151 |
| MFI in FL3 (a.u.) | 634,600 | 651,000 | 726,080 | 718,860 | 704,560 | 687,000 ± 41,500 | |
| FL2/FL3 | 0.0125 | 0.0124 | 0.0114 | 0.0115 | 0.0115 | 0.0119 ± 0.0005 | |
| Measured value by FCM | Asta. (mg/g) | 0.81 | 0.83 | 0.87 | 0.86 | 0.84 | 0.84 ± 0.02 |
| Car/Chl | 1.83 | 1.82 | 1.69 | 1.69 | 1.70 | 1.75 ± 0.07 | |
| Accuracy analysis (%) | Asta. | 87.75 | 90.17 | 94.41 | 93.23 | 91.22 | 91.36 ± 2.61 |
| Car/Chl | 79.15 | 78.57 | 72.92 | 73.03 | 73.44 | 75.42 ± 3.15 | |
| Sample 2 | MFI in FL2 (a.u.) | 12,177 | 12,281 | 12,545 | 12,408 | 12,186 | 12,319 ± 156 |
| MFI in FL3 (a.u.) | 558,740 | 565,610 | 598,240 | 591,460 | 580,000 | 578,800 ± 16,700 | |
| FL2/FL3 | 0.0218 | 0.0217 | 0.0209 | 0.0209 | 0.0210 | 0.0213 ± 0.0005 | |
| Measured value by FCM | Asta.(mg/g) | 1.56 | 1.58 | 1.64 | 1.61 | 1.57 | 1.59 ± 0.03 |
| Car/Chl | 3.13 | 3.12 | 3.02 | 3.02 | 3.02 | 3.06 ± 0.06 | |
| Accuracy analysis (%) | Asta. | 94.75 | 95.99 | 99.17 | 97.52 | 94.86 | 96.46 ± 1.88 |
| Car/Chl | 103.65 | 103.28 | 99.86 | 99.90 | 100.00 | 101.34 ± .95 | |
| Recovery (%) | Asta. | 103.58 | 103.33 | 105.16 | 102.93 | 99.45 | |
| Car/Chl | 78.60 | 78.73 | 80.41 | 80.31 | 80.02 | ||
| Average recovery (%) | Asta. | 102.89 ± 2.10 | |||||
| Car/Chl | 79.61 ± 0.88 | ||||||
| Relative standard deviation of recovery (RSD, %) | Asta. | 2.04 | |||||
| Car/Chl | 1.10 | ||||||
MFI: mean fluorescence intensity; FL2: 585 nm ± 20 nm; FL3: >670 nm; a.u.: arbitrary unit; Asta.: astaxanthin; Car/Chl ratio: the carotenoid-to-chlorophyll ratio; Sample 1: C. zofingiensis cells with astaxanthin content of 0.92 mg/g and Car/Chl of 2.32 (determined by HPLC); Sample 2: C. zofingiensis cells with astaxanthin content of 1.65 mg/g and Car/Chl of 3.02 (determined by HPLC).