Instrumental Uniaxial Compression Test of Gellan Gels of Various Mechanical Properties Using Artificial Tongue and Its Comparison with Human Oral Strategy for the First Size Reduction

Instrumental compression test using artificial tongue was carried out to compare the fracture profile of gels with the first oral strategy for size reduction by humans (termed as the first size reduction). Gellan gel samples, whose size and shape were the same as those of artificial tongue, were prepared in a wide mechanical range and were compressed uniaxially on artificial tongue at crosshead speed of 10 mm/s. When apparent Young's modulus of artificial tongue was approximately 55 kPa, fracture probability of gels corresponded to the ratio of subjects who decided to use tongue‐palate compression instead of mastication. This was applicable to the gels whose fracture strain was below 65% but not to the gels whose fracture strain was above 70% within the range of fracture stress tested; approximately 30–100 kPa. Fracture strain should be a critical initial mechanical parameter that relates to the decision of oral strategy. PRACTICAL APPLICATIONS: There is an increasing demand for texture‐controlled foods that can be consumed by tongue‐palate compression without the need of mastication as the number of people having oral deficiency is expanding. It is proved that instrumental texture evaluation method that the authors developed is applicable to a wide range of food texture, particularly for viscoelastic gels, with some changes of instrumental operation condition if necessary, providing a simple method for assessing textural acceptability of food products for consumption without using human subjects. From an industrial point of view, this method can contribute to the texture design of food products that are comfortable to eat and thus to the improvement of quality of life for those people. From a scientific point of view, this method can contribute to better understanding of the physiology of human tongue‐palate compression as an oral strategy for size reduction, particularly during consumption of solid or semi‐solid foods.