Strength Parameters of Packaged Roma Tomatoes at Bioyield under Compressive Loading

Abstract

Compression test was conducted on packaged Roma tomatoes to study the effects of stage of ripeness, level of vibration and container type on load, deformation and stress at bioyield point of the fruit. Tomatoes harvested at three stages of ripeness: unripe (5.6 Brix %), half-ripe (3.9 Brix %), and full-ripe (3.2 Brix %), were packed in plastic crate and raffia basket and were subjected to three levels of vibration: non-vibrated, low vibration (frequency 3.7 hz) and high-vibration (frequency 6.7 hz). The tomatoes were then compressed at a loading rate of 2.50 mm/min^-1 in a Testometric Universal Testing Machine. Data obtained directly from computer printout were statistical analyzed using the SPSS 110 software package. Load and stress at bioyield decreased significantly (P=0.05) with advances in ripeness stage of the fruit. of increasing vibration significantly (P=0.05) increased deformation at yield and also reduced load and stress at bioyield.

Keywords: Roma tomato, Packaging, Mechanical damage, Strength parameter, Bioyield, Ripeness, Vibration, Universal Testing Machine