Effect Of Cooking On The Migration Of Lead And Cadmium In Pots And Safety Evaluated

Cooking is an important part of food processing. Lead and Cadmium in pots were likely to dissolve into food during the process due to the certain conditions, which may cause food pollution even health effects. In this paper, the migration and sources of Lead and Cadmium were studied and the security of them were evaluated. The research results indicated that:(1)The digestion solution and digestion methods were selected. The result showed that nitric acid and microwave were acted as digestion solution and digestion method. By adjusting the current and gas flow rate of the instrument, the graphite furnace - atomic absorption spectrometry was established as the detection method of Lead and Cadmium. It was investigated that Lead and Cadmium respectively had a good linear relationship in the range of 0.1-20μg/L and 0.02-1.0μg/L. The average recoveries of Lead and Cadmium were 93.75-96.88% and 95.50-104.25%, and the relative standard deviations of Lead and Cadmium were 0.723% and 1.196%.(2)The simulation experiments were focused on the effect of Lead and Cadmium’s migration in pots and cooking water into food, also the safety of them were evaluated. The research indicated that four kinds of pots made Lead and Cadmium release in boiling, and it has no risk on human health. The release rate of Lead was 0.109 -1.975μg/L and Cadmium was 0.025 -0.287μg/L. It was obvious that the results of this research were minor than the PTWI of Lead and Cadmium limited by JECFA. But it had certain risk to human health when Lead and Cadmium from cooking water in range of Standards because of the quality of drinking water.(3)In order to investigated the migration of Lead and Cadmium of three kinds of pots during the cooking process, water and 4% acetic acid, 15% ethanol were simulated the neutral foods, acidic foods and alcoholic foods in contact with pots in cooking respectively.The results indicated that Lead and Cadmium of the three kinds of pots could increase the temperature and cooking time. The release rate of Lead and Cadmium from three kinds of pots was the highest when it exposed to 4% acetic acid. The release rate of Lead and Cadmium on Iron pot was significantly higher than Aluminum Alloy pot and Ceramic pot when it exposed to the three kinds of food on simulate solution.(4)The effects of acid degree, alcohol content of food and frying process on the migration of Lead and Cadmium of pots in cooking were studied. The research results indicate that the effects of acid degree on the migration of Lead and Cadmium in cooking,the Lead and Cadmium on pots were both increased when the decreased of pH. It was definited that 15% ethanol had significant effects on the migration of Lead and Cadmium(p<0.05), but 10% ethanol and 20% ethanol had no significant effect (p>0.05). Due to the different kinds of material pots, fired vegetable oil had an impact on the release of Lead and Cadmium. When the pots heated for one hour, the release of Lead and Cadmium of these three kinds were increased while the cooking time added; When the pots heated for one or two hours, the rate of Lead and Cadmium in Iron pot and Aluminum Alloy pot began to reduce.