Kinetics of 5-hydroxymethylfurfural (5-HMF) formation and colour change in date fruit fillings stored at different temperatures

Abstract

Date fruit filling is a healthy alternative for the food sector due to its beneficial compounds, dietary fibre, minerals and vitamins. It is also widely used in the baking industry as a filling in pastries and biscuits as a sweetener. In the present study, the stability of date fruit filling, as a function of storage time and temperature, was determined. 5-HMF generation and colour changes were monitored at 25, 35 and 45 °C. Results showed that 5-HMF formation increased linearly with an increase in storage time and temperature and followed a zero-order reaction. L* and hue values decreased linearly and also followed a zero-order reaction. In addition, 5-HMF had a negative correlation with L* (r = 0.832–0.863, p < 0.05) and hue values (r = 0.919–0.953; p < 0.05). No fitting model was found for the changes in other CIE colour parameters. Activation energies of 145.39, 56.64 and 71.05 kJ mol–1 were determined for 5-HMF formation, L* and hue values, respectively. Consequently, date fruit fillings stored at 25 °C provided a desired result of 5-HMF formation and colour loss compared to fillings stored at 35 and 45 °C.