Changes in purine and uric acid content in edible insects during culinary processing

Recently, edible insects were proposed to be promising alternative foods combining nutritional, environmental, and economic benefits. While composition of the basic nutrients of insects is quite well known, little is known about other compounds contained in them such as purines. From this point of view, raw insects were reported to belong among purine-rich foods. However, they are generally consumed after culinary processing, which is known to affect nutritional composition of foods. Therefore, we aimed to analyze the effect of culinary processing (including various combinations of boiling, roasting, blanching, baking, and oven drying) on purine (adenine, guanine, xanthine, and hypoxanthine) contents and their metabolite (uric acid) in three insects (Tenebrio molitor, Gryllus assimilis, and Acheta domesticus) fit for human consumption using RP-HPLC with UV detection. According to obtained data, boiling for 15 min significantly reduced the purine content in T. molitor but did not affect the purine levels in A. domesticus and G. assimilis. In contrast, the purine content increased in all insects after baking (especially at 220 °C). The information this study provides can help people suffering from gout interested in entomophagy to choose the best culinary treatment of insects to help prevent gout symptoms.