Heat-induced compounds development in processed tomato and their influence on corrosion initiation in metal food cans

Selected ion flow tube mass spectrometry (SIFT-MS) and ion chromatography (IC) were used to investigate the presence of volatile and nonvolatile compounds in canned tomatoes and in the polymeric lining before and after retorting the cans. This allowed us to observe if these compounds contributed to corrosion and the migration of iron and tin compounds from the cans to the tomatoes. Diced Roma tomatoes and other simulant treatment groups were sealed in two-piece tinplated cans (controls in glass jars), retorted at 121℃ for 30 min, then stored at 49℃ for 50 days. Results showed that thermal degradation of amino acids in the tomatoes gave rise to volatile methyl sulfides and nonvolatile nitrogenous compounds which were subsequently sorbed by the can lining. SIFT-MS showed a 20-fold increase in dimethyl sulfide concentration. Inductively coupled plasma (ICP-MS) results showed fourfold and 16-fold increases in iron and tin compounds, respectively, that migrated from the metal to the tomatoes as a result of acid and electrolyte interactions.