The development of thickened fermented rice milk formulation for people with dysphagia: A view of multiple in vitro simulation methods.

Based on the huge blank of thickened fluid staple food for people with dysphagia, multiple in vitro simulations were utilized to develop the thickened fermented rice milk. Here, the effect of amylase content, hydrolysis time and thickener content were considered. The rheological study and Cambridge throat evaluation revealed that hydrolysis could significantly reduce the viscosity and yield stress of fermented rice milk, accompanied by the decreased swallowing residue. The addition of thickeners increased the viscosity and cohesion of the fermented rice milk due to the entanglement network formation, which facilitated the formation of lubricating film, decreased the coefficient of friction, and improved the sensory score. Increasing thickener content from 0 % to 0.5 % induced the longer oral transition time (0.26 s to 0.45 s), more residue (0.85 g to 2.07 g) and shorter stretching length (850.42 mm to 313.62 mm) shown in the Cambridge throat simulation. Among them, the fermented rice milk with 0.40 % thickener showed the best sensory properties, and its swallowing properties evaluated by computer simulation also suggested concentrated frequency distribution of velocity, shear rate and viscosity without splashing or choking compared with the normal fermented rice milk, showing excellent swallowing safety.