Measuring ring tensile stress and strain of surimi gels using a novel ring tensile test with image analysis

• The concept of true stress–strain was applied to estimate tensile properties.
• Laplace’s law was applied to remove the dependence of the width and inside diameter.
• Digital image correlation (DIC) was used to identify the validity of Laplace’s law.
• The dimensionless thickness ratio was developed to estimate ring tensile stress.

A ring tensile test with image analysis to measure failure properties, such as failure ring tensile stress (σfσf) and strain (εfεf), of surimi (Itoyori   A grade) gels with varying moisture content (76–80%) was developed using Laplace’s law. The novel approach was validated for different inside diameters and thicknesses. Digital image correlation (DIC) was used to identify the validity of Laplace’s law. For normalization, Laplace’s law was applied to eliminate the dependence of the width and inside diameter. The values of σfσf by thickness, including the zero point, was accurately described using linear regression analysis (r2 > 0.99). This shows that σfσf can estimate the reference σfσf regardless of thickness. The values of σfσf of the ring specimen were best fit with a linear function to moisture content (r2 > 0.94). The results of εfεf for differing moisture content and thickness showed no significant differences (p < 0.05).