TEXTURE EVALUATION BY UNIAXIAL COMPRESSION OF SOME SNACK FOODS

Abstract

ABSTRACT Three ready‐to‐eat snacks, viz., deep‐fat fried batter drops made from thick chickpea flour batter, extruded corn balls and puffed rice, were subjected to uniaxial compression at four different compression speeds of 0.01, 0.1, 1.0 and 10.0 mm/s to obtain maximum force, fracture strain, slope of the force–deformation curve (instrumental firmness) and the number of major and minor peaks during compression. The instrumental firmness was dependent on the compression speed and was correlated (r = 0.656, P ≤ 0.001) with sensory firmness values. Fracture strain, maximum force and number of peaks increased with compression speed. The principal component analysis indicated that the low compression speed of 0.1 or 0.01 mm/s would be appropriate for testing crisp snack foods to have a detailed fractural behavior.PRACTICAL APPLICATIONSThe specific application of the present findings lies in the determination of specific well‐defined instrumental texture parameters based on fracture characteristics of nonuniform snacks and similar products. The advantage of the proposed method is the ease in conducting experiments that require a texture testing machine to provide the force–deformation characteristics. The method is useful for quality control of snack foods, as well as for researchers who wish to have an in‐depth look at the fracture mechanism in combination with microstructural observations. A low compression speed of 0.1 or 0.01 mm/s is desirable to visualize minor, as well as major, fractures.