Peptide fingerprinting of Hermetia illucens and Alphitobius diaperinus: Identification of insect species-specific marker peptides for authentication in food and feed.

Insects have been proposed as new source of proteins to meet the growing demand connected to the increasing world population. In the EU the inclusion of insect proteins in feed and food is strictly regulated. Hence, analytical methods able to discriminate and identify different insect species in food and feed are a necessity. In this work, a peptidomic approach was applied to determine peptide biomarkers for two edible insect species: lesser mealworm and black soldier fly. Three species specific peptide biomarkers were identified using LC-MS/MS. The two insects were mixed with fish standard feed at different concentrations, to evaluate the feasibility of their use as markers in complex matrices. The detection of marker peptides was confirmed down to 1% insect amount. The data here reported constitutes the first proof of concept for the potential application of the peptide marker approach for the identification and quantification of insect ingredients.

Assessment of Enzymatic Improvers in Flours Using LC-MS/MS Detection of Marker Tryptic Peptides.

Enzymatic improvers are enzymes obtained from microbial or fungal cultures, added as technical adjuvants to flour, with the aim of improving the dough characteristics in bakery products. They are used in a low ppm range and, being technical adjuvants, can go undeclared on the label. Many types of enzymatic improvers are present on the market, such as amylases, lipases, proteases, xylanases, glucose oxidases, and others, each with a different function. Analytical methods capable of detecting these enzymes are needed, particularly for bakery companies, in order to monitor the quality of raw materials and to detect any undeclared presence. In the present work, specific peptide markers, obtained by enzymatic digestion, have been used to detect the presence of enzymatic improvers by LC-MS/MS techniques. Promising results were obtained for some enzymes acting on the carbohydrate fraction (glucoamylase, glucose oxidase, xylanase) in which amounts as low as 20 ppm could be identified in blind flour samples. For lipases and proteases the method proved to be very effective in terms of specific identification, even if less sensitive.