An engineering method to evaluate the crisp texture of fruit and vegetables

Abstract

Precise measurements of the deformation and fracture behaviour of food can be difficult because of problems associated with the produce, for example, sample preparation, gripping, size and geometry. The aim of this study was to characterise fruits and vegetables in terms of fracture properties using an established engineering test method and geometry, the Single-Edge Notched Bend (SENB). The SENB geometry was found to be readily applicable to crisp food produce such as carrots, celery, and apples, which exhibit linear elastic behaviour up to fracture. Fracture toughness and fracture energies were found to be in the range 10-50 kPa m1/2 and 40-400 J m-2, respectively. The structure of these materials was confirmed, using confocal microscopy, and related to the observed fracture behaviour. Cell size and intercellular spaces influenced the values of fracture toughness and fracture energy.