Screening of soy and milk protein hydrolysates for their ability to activate the CCK1 receptor

► Potential of soy and milk protein hydrolysates to activate CCK1R was evaluated. ► Fluorescence plate reader was not suited to measure complex formulations. ► Confocal microscope yielded specific and reliable results. ► Gastrointestinal digested 7S fraction of soy protein has significant CCK1R activity.