Abstract The effect of weight ratio of protein to sugar (0.17–7.83), temperature (40–60°C) and time (24–120 h) on the antigenicity of β-lactoglobulin (β-LG) in conjugates of whey protein isolate (WPI) with glucose was investigated. Response surface methodology was used to carry out an optimisation of the reaction conditions leading to the minimum antigenicity of β-LG. Conjugation of WPI with glucose could reduce effectively the antigenicity of β-LG. This reduction of antigenicity could be controlled by regulating three independent variables (weight ratio of WPI to glucose, temperature and time). The model for optimal reaction conditions of a lower antigenicity of β-LG was established. Weight ratio of WPI to glucose had the greatest effect on the antigenicity of β-LG. Reaction time influenced the antigenicity of β-LG to a lesser extent.