Crucial role of remaining lactose in whey protein isolate powders during storage
Résumé
This study aimed to investigate the effect of lactose on the ageing-induced structural changes through a
varying lactose content in whey protein powders. In this scope, four powders differing in their lactose
content (0.1e16 w/w %) were stored at 40 C and 60 C for up to 3 months and sampled periodically. A
small variation in lactose content of WPI powders was found to affect the level of structural and functional
changes during powders ageing. At a higher lactose content (2.6 w/w %), proteins were more
rapidly lactosylated and aggregated, with a higher rate than the control WPI powder; whereas at a lower
content (0.1 w/w %) the rate of lactosylation and aggregation was considerably limited. These results
highlighted the great contribution of the Maillard reaction during ageing of WPI powders. Reducing
lactose content in the WPI powders is a promising way to extend their stability among storage.