An Estimation of Firmness for Solid Ellipsoidal Fruits

This paper deals with a non-destructive firmness estimation method using vibrational characteristics for solid fruits of oblate ellipsoidal shape. In association with the previous work, a general estimation formula is proposed, which is suitable for both prolate and oblate solid ellipsoids. The applicable range of the new firmness index is at least between axis ratio of 0·4 and 2·0 from finite element simulations.