Table 1 Parameters of model calibration and prediction.

n_calibration / n_prediction

83 / 13

61 / 12

48 / 13

Regression model

Linear

Exponential

PLS

Calibration range

2 × 10⁵ - 6 × 10⁶ cells.ml^-1

1 × 10⁴ - 1 × 10⁶ cells.ml^-1

10 - 600 U.l^-1

Preprocessing

N.A.

N.A.

1^st derivative, SNV

Latent factor

N.A.

N.A.

7

R²

0.94

0.97

0.94

RMSE

4.4x10⁵ cells.ml^-1

3.2x10⁵ cells.ml^-1

N.A.

RMSEC

N.A.

N.A.

29 U.l^-1

RMSECV

N.A.

N.A.

44 U.l^-1

RMSEP

1.25x10⁵ cells.ml^-1

7.4x10⁴ cells.ml^-1

9 U.l^-1