Hydroxymethylfurfural: an indicative parameter of heat damage in cereal products

The main chemical changes occurring during biscuit cooking result from two complex reactions involving reducing sugars: the Maillard reaction and caramelisation, both of them being responsible for non enzymatic browning. These reactions were assessed by determinations of furosine (Fu), hydroxymethylfurfural (HMF), and colour at different times (each 2 min) of the cooking process (10 min). The surface colour of biscuits was carried out with L* a* b* parameters, and the global browning development was measured by the reflectance of the whole biscuit in powder. Simultaneous formation of HMF, Fu and browning were investigated to evaluate the correlation between parameters during cooking and identify the best indicators of the biscuit quality. Fu was almost stable during the first 4 min before decreasing in the last 6 min. In contrast, HMF exponentially increased after 4 min, when the water activity reached 0.6. Reflectance was linearly correlated to cooking time and was well correlated to HMF. We conclude that HMF could be a useful indicator for controlling the cooking process of biscuits.