Physicochemical and mechanical-textural properties of tomatoes for processing

Abstract

Understanding the mechanical responses and physical properties of plant materials can help to improve methods and technologies for reducing post-harvest losses, especially of bulk processed tomato fruits. This study aims to evaluate the biometric physicochemical, and mechanical-textural characteristics of the ripe fruit from five tomato cultivars for processing. The longitudinal, peduncular scar, pericarp and epidermis diameters vary significantly. The ash content of the pulp ranged from 0.40 to 0.92g 100g-1, and the total pectin from 0.218 to 0.469mg 100g-1, and all cultivars differed in these parameters. The mechanical-textural properties varied significantly, the firmness of the skin by compression in the standing fruit test correlated negatively with the firmness of the pulp by compression of the fruit in the lying position (-0.79*). The modulus of elasticity of the skin on standing fruit compression ranged from 19.65 to 11.99N mm-2, and correlated positively with the modulus of elasticity of the skin with the fruit in the lying down position (0.79*). Fruits with larger pericarp thickness showed higher skin firmness, lower moisture and higher pectin content. Fruits positioned longitudinally (lying) on the texturometer platform require greater force (N) to break. Firmer fruits in a standing position have a greater skin elasticity modulus. Larger fruits have smaller skin and flesh firmness, and smaller fruits are more recommended for mechanical harvesting. Among the cultivars studied, the ones with the best mechanical properties were TC2736 and CVR2909, which also presented smaller longitudinal diameters, peduncle scar, fresh mass and volume.