Cooking-Induced Corrosion of Metals

Abstract

Uptake of metal ions into rice occurs while it is being cooked in metal vessels, leading to corrosion of the utensils. This study deals with silver, copper, and aluminum uptake during cooking in respective vessels, with a special emphasis on silver. The metal uptake is routed through solution, enhanced in the presence of specific anions like carbonate, and attenuated when the rice is polished. The concentration of silver in rice increases with the time of cooking with a concomitant decrease in the concentrations of Fe and Zn, suggesting a substitution mechanism for metal ion uptake. The results for some common rice varieties of use across the Indian subcontinent are presented. Similar behavior was observed for cooking in copper and aluminum vessels. Among the three metals studied, aluminum showed reduced uptake. Studies have been done to probe the interaction of metal ions with glucose and sucrose, and efficient complex formation was detected with all these ions, implying that starch can also form complex...