Prediction of riboflavin and ascorbic acid concentrations in skimmed heat-treated milk using front-face fluorescence spectroscopy
Ulises Alvarado, Anna Zamora, Óscar Montaño Arango, Jordi Saldo, M. Castillo
Abstract
The objective of this work was to obtain degradation kinetic models of riboflavin and ascorbic acid, and to evaluate the potential of front-face fluorescence (FFF) spectroscopy to predict their concentration in milk after thermal processing. A factorial design with three temperatures (70, 80 and 90 °C) and nine times (from 0 to 60 min) of heat treatment was used. Degradation kinetics of both vitamins were of first order. Predictive kinetic models using the Arrhenius equation had a variability coefficient of 2.26 and 3.64% for riboflavin and ascorbic acid, respectively. With fluorescent predictors such as tryptophan, Maillard compounds and riboflavin, prediction models with coefficients of variation smaller than 3.57% for riboflavin and ranging from 4.24 to 14.25% for ascorbic acid were obtained. In conclusion, FFF is a viable alternative to predict riboflavin and ascorbic acid content of milk which could allow in-line monitoring and control of thermal damage.