Table 4.
Statistical descriptors for the best calibration equations obtained from NIR spectra and mineral composition data obtained by ICP-MS on flour samples.
| Mineral | Math Treatment | N | Mean | SD | Min Est. | Max Est. | SEC | SECV | RSQ |
|---|---|---|---|---|---|---|---|---|---|
| Mg | SNV 2,4,4,1 | 114 | 0.0767 | 0.0205 | 0.0153 | 0.1381 | 0.0038 | 0.0048 | 0.96 |
| P | Detrend 2,10,10,1 | 110 | 0.292 | 0.0911 | 0.0187 | 0.5653 | 0.0206 | 0.0208 | 0.94 |
| K | Detrend 0,0,1,1 | 115 | 0.6794 | 0.2211 | 0.0162 | 1.3426 | 0.0293 | 0.039 | 0.98 |
| Ca | Detrend 0,0,1,1 | 115 | 0.0685 | 0.0211 | 0.0052 | 0.1316 | 0.0051 | 0.0056 | 0.94 |
| Fe | SNV 2,4,4,1 | 108 | 49.1007 | 18.2117 | 0.0000 | 103.7358 | 6.5112 | 8.984 | 0.87 |
N: number of samples after removing the outliers; SNV; standard normal variate; SD: standard deviation; RSQ: multiple correlation coefficients; SEC: standard error of calibration; SECV: standard error of cross-validation.