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.

Folate contents in insects as promising food components quantified by stable isotope dilution.

Concerning the increasing population, edible insects are of growing interest due to several advantages such as sustainable production and as a source of high-quality nutrients. One of the less studied nutrients are folates, in the context of insects is folates, which play an important role in human metabolism. In the article, we describe how six different insect species are reared and extracted for five common folate vitamers by high-performance liquid chromatography interfaced with tandem mass spectrometry (LC-MS/MS). For this purpose, house crickets (Acheta domesticus-adults), Jamaican field crickets (Gryllus assimilis-adults), discoid cockroaches (Blaberus discoidalis-nymphs), migratory locusts (Locusta migratoria-adults), mealworms (Tenebrio molitor), and lesser mealworms (Alphitobius diaperinus) were investigated. The total folate content differs between 59.1 ± 6.50 and 143 ± 11.1 µg/100 g. Also, the feed, which was adapted to the needs of the insects and differed for some species, was extracted for their total folate content. The four different feed compositions (rapeseed, chicken feed, bramble leaves, and a mix of chicken feed, wheat bran, and carrot/apples) showed a folate content of about 100 µg/100 g, except for hay, where the content was 300 µg/100 g. In general, the insect folate content is comparable to other food and seems to be a promising source of folates. However, the amount of consumption needed to meet the requirement must also be considered. Moreover, the effect of different influencing factors is not yet entirely clear and needs further investigation.