Hydrocolloids for enhancing satiety: Relating oral digestion to rheology, structure and sensory perception

Abstract

Satiety expectations can be closely related to the structural changes that take place in the mouth. An important role of hydrocolloids is to impart viscosity, which has a key effect on the feelings of richness, mouthcoating and fullness. In this study, native and modified corn starch, l-carrageenan and guar gum were used to formulate milkshakes. Expected satiety was rated (106 consumers) and the perception of various attributes was studied. The rheological properties of the milkshakes without and with added saliva were analysed and observed with a light microscope during in vitro oral digestion. Disintegration of the swollen starch granules by saliva was observed mainly in the modified starch sample. The structure of the milkshakes prepared with l-carrageenan and guar gum was preserved better. It could be hypothesized that the starch would provide lower expected satiety due to the extensive in-mouth disintegration. However, the sensory analysis showed that the modified starch milkshakes obtained the highest expected satiety scores, with consumers finding them homogeneous, thick in the mouth and very creamy. These results suggested that consumers related satiety more with the thick and creamy characteristics at the very start of the consumption than with the loss of structure in mouth. Sensory properties affect the assessment of the satiating capacity, especially texture, which is directly related to the orosensory exposure and, therefore, to the feeling of fullness that the milkshakes elicit. The present study casts light on the factors affecting in-mouth perception of different hydrocolloids used to design foods with enhanced satiety.