Impact of In Vitro Gastrointestinal Digestion on the Phenolic Bioaccessibility and Bioactive Properties of Insect-Containing Beef Burgers

Abstract

Mealworm, migratory locust, and house cricket have recently been recognized by the European Commission as novel foods, thus being suitable in different food applications. In this work, we tested their powders as meat extenders at 5% (w/w) inclusion in beef burgers, considering their ability to vehicle phenolic compounds during simulated in vitro static gastrointestinal digestion (INFOGEST). Insect powders were abundant in different phenolic classes, recording the highest values in locust (LP; 314.69 mg/kg), followed by cricket (CP; 113.3 mg/kg) and mealworm (MWP; 51.9 mg/kg). Following a pan-cooking process, LP burgers were confirmed as the best source of phenolics, with a marked abundance of flavonoids and phenolic acids. Interestingly, the insect powders were found to affect the in vitro gastrointestinal bioaccessibility of phenolic compounds when compared with the CTR burger, likely promoted by the interactions between the phenolic compounds and proteins characterizing the tested insect powders. Among the most discriminant phenolic metabolites at the gastrointestinal level, we found several phenolic acids (mainly hydroxycinnamics), recording the highest content for the digested CP-containing burgers. Finally, stilbenes showed significant correlation values at the intestinal level with both antioxidant and enzymatic activities, while total flavonoids were the most correlated with the inhibition of acetylcholinesterase. Taken together, our preliminary findings demonstrated that insect powders added to beef burgers can promote the bioaccessibility and potential bioavailability of phenolics in the distal tracts of the intestine.