Application of absorbance values used in wineries for estimating CIELAB parameters in red wines

Multiple and simple regression analyses were assessed to establish mathematical models that allow the evaluation of CIELAB parameters from absorbance values at 420, 520 and 620 nm. All these variables were measured in 180 commercial red wines, using 130 of them to obtain the mathematical models. The results showed that the CIELAB parameters L*, a* and C* for the CIE D65/10° illuminant/observer conditions can be correctly estimated (with small standard error of estimation) from absorbance values at 520 nm, as an independent variable. However, the parameters h and b* showed higher average errors between the predicted and observed values, but they were correctly estimated using multiple linear regression models with the three absorbances at 420, 520 and 620 nm (b*) or using the ratio of A420 to A520 as independent variable (h). The models obtained could be helpful to wineries that in general, do not have the necessary equipment and software to determine the CIELAB parameters, which are recognized as being the best parameters for defining the colour of wines.