Effect of Maturity Level and Fruit Size on Mechanical Properties of Tomato Fruit (Solanum lycopersicum)

Abstract

Knowledge of the mechanical properties of fruit is an important parameter for post-harvest handling in order to minimize damage to the product. The purpose of this study was to analyze the effect of maturity level and fruit size on the changes in the mechanical properties of tomatoes (Solanum lycopersicum). The study was conducted on three levels of maturities, namely green, turning, and red as well as three kinds of fruit sizes, namely small, medium, and large with a completely randomized design in three replications. Measurement was done by compressing the tomato samples using a compression machine equipped with a loadcell (Loadstar 10kg) and a linear variable deformation transformer (KTC 50mm). Obtained data were than analyzed according to the ASAE S368.4 DEC2000 (R2008) to determine modulus of elasticity, contact area, and maximum compression stress. The results showed that the modulus of elasticity was significantly affected by the maturity level, whereas Smax was significantly affected by both the size and maturity level, and the contact area only affected by the size of the sample. The interaction of the size and maturity level was found to be significant for the modulus of elasticity and Smax values. It was also observed that the tomato of green maturity had the highest modulus of elasticity than tomatoes at turning and red ripeness levels. The smallest modulus of elasticity was 0.5758 MPa for small red tomato, while the largest was 1.9694 MPa for small green tomato. For the contact area, it was found that as the size of the sample increased, the value of the contact area was also increased. The smallest value of contact area was found for small red tomato, which was 0,0006 m2 and the largest value was for large red tomatoes which was 0,0018 m2. The green tomatoes had the largest Smax, followed by turning tomatoes and the last one was red tomatoes. The smallest Smax was 0.1081MPa for large red tomato, while the largest was 0.6427 MPa for small green tomato.