2008 Volume 2 Issue 1 Pages 7-13
Firmness is an important biomaterial property in assessing the internal quality of agricultural products. This article briefly summarizes recent research results of a new frequency-based firmness index for solid fruits and vegetables of ellipsoidal shape. This new firmness index is in fact a generalization of the conventional ones targeted for spherical fruits and vegetables. Meanwhile, it can also serve as a dynamic Modulus of Elasticity (MOE) estimator. The development of this new firmness index extends the potential applications of non-destructive firmness estimation to non-spherical fruits and vegetables. The theory of formulation is first introduced, followed by a discussion on two experimental case studies, “tri-star” pear and Chinese radish. The results show that the new firmness index is indeed more robust and accurate, especially for ellipsoids with long principal axes ratios.