Effect of Tomato Juice on Electrochemical Properties of Brass, Galvanized and Stainless Steel

Abstract

Tomatoes (Lycopersicon esculentum), is a fleshy berry regarded as very popular perishable fruit as well as vegetable grown throughout the tropical and temperate regions of the world. This research work investigated the effect of tomato juice on the electrochemical properties of brass, galvanized and stainless steel using potentiostatic polarization method and weight loss technique at room temperature. The samples were cut into sizes, 2 cm by 2 cm for galvanized and stainless steel, while brass a cylindrical shape of 2.5 mm diameter was cut into 5 cm height, the cut metallic samples was weighed using a sensitive weighing balance and recorded. The pH of the tomato juice was measured and the cut metallic samples were immersed into the containers filled with tomato juice and exposed for a period of 30 days. Weight losses of samples and pH of the tomato juice were determined at an interval of 5 days and the corrosion rates were evaluated. The results showed that brass and stainless steel had very low corrosion rates which decreased with time. High corrosion attack was observed on the galvanized steel and this is shown by the high corrosion current density and corrosion rate obtained on the polarization curve showing active corrosion reaction properties. The pH of the tomato progressed to neutrality within five days and to alkalinity at the end of the thirty days test for galvanized steel while the pH of the tomato juice was less acidic at the end of the thirty days test for both brass and stainless steel. Stainless steel was confirmed as best storage material for tomato juice in this study.Keywords: Corrosion, electrochemical, potentiostatic polarization, weight loss, tomato, metal