Study of the changes in the purine content in foods after heat cooking

Abstract

In order to serve the dietary advice for patients with gout and hyperuricemia, we have reported purine content in many foods and drinks. Food is usually cooked by some heat treatment and is eaten. In this study, we determined the changes in the purine content in the chicken soup stock, raw chicken, and dried shiitake after heat cooking. Especially for the degradation of inosine mononucleotide (IMP) and guanosine mononucleotide (GMP) which were umami component, we focused on the difference in heating temperature, time, and tools.

As a result, by cooking the chicken soup stock in boiling water, all purine contents increased significantly compared with other temperatures. In addition, it was found that IMP and GMP as umami, are more resistant to decomposition by boiling than by microwave ovens. When chicken meat was boiled, high amounts of hypoxanthine, inosine, and IMP were detected in the eluate. Heating with the microwave oven extracted all purines from chicken meat more than boiling. From dried shiitake, purines were eluted in a short time using the microwave oven, and the umami component was hardly decomposed. Thus, it was found that there was a difference in profile of purine elution and decomposition pattern by the heating method based on different composition of purines in foods. We recommend to use appropriate heating method suitable for gouty patient according to food.