Potential of front face fluorescence associated to PLS regression to predict nutritional parameters in heat treated infant formula models.

Abstract This work shows that front face fluorescence spectroscopy associated to partial least squares (PLS) calibration is a fast and simple method to assess the nutritional impact of heat treatment on milk samples. Emission spectra of tryptophan (Trp) and of advanced Maillard products (AMP) were recorded on intact milk samples non-heated and heated at seven temperatures (72 °C, 80 °C, 87 °C, 95 °C, 100 °C, 110 °C and 115 °C) for six different times (from 2 min to 9.5 min) by means of front face fluorescence. PLS calibrations were constructed in order to indirectly quantify three indicators: vitamin C, protein denaturation and accumulation of Maillard products using the fluorescence of advanced Maillard products and soluble tryptophan method (FAST). The prediction models allowed obtaining an estimation of these indicators with a relative error of 12% for vitamin C and about 18% for the FAST index and soluble whey protein ratio.