Detection of Alphitobius diaperinus by Real-Time Polymerase Chain Reaction With a Single-Copy Gene Target.

Aline Marien,Frédéric Debode,Hamza Sedefoglu,Stéphanie Guillet,Gilbert Berben,Benjamin Dubois,Frédéric Francis,Olivier Fumière,Jean-François Morin,Julien Maljean

doi:10.3389/fvets.2022.718806

Abstract

Use of edible insects as an alternative source of proteins in food and feed is increasing. These last years, numerous companies in Europe have started producing insects for food and feed purposes. In the European Union, the use of edible insects for human consumption falls within Regulation (EU) No. 2015/2283 on novel foods. For feed, Commission Regulation (EU) 2017/893 authorizes seven insect species as processed animal proteins for aquaculture. Methods of authentication are required to check the conformity of the products. In this study, we propose a real-time polymerase chain reaction (PCR) method for the specific detection of the lesser mealworm (Alphitobius diaperinus), one of the species included in the shortlist of authorized insects. The selected target is the cadherin gene with a single-copy (per haploid genome) illustrated by our experimental evidence. The PCR test amplified a 134-bp fragment of the cadherin gene. The qualitative method was assessed toward several performance criteria. Specificity was checked against 54 insect species next to other animal and plant species. The sensitivity, efficiency, robustness, and transferability of the PCR assay were also successfully tested. Finally, the applicability of the test was assessed on real-life processed samples (industrial meals) of A. diaperinus. The study also showed that there seems to be a huge confusion on the correct labeling of the marketed mealworms. We did not succeed to get Alphitobius laevigatus samples. They all appeared to belong to the A. diaperinus taxon.

Highlights

In recent years, edible insects are becoming an increasing alternative source of proteins
This study proposes the first real-time polymerase chain reaction (PCR) method for specific detection of lesser mealworm (A. diaperinus)
The cadherin gene of A. diaperinus was used to select a piece of DNA that is specific to the considered insect species

Summary

Introduction

Edible insects are becoming an increasing alternative source of proteins. The main reason for it is that the food production rate is expected to be lower than the population growth [1]. Insects represent a promising strategy for enriching food in some nutrients, thereby achieving a better nutritional balance [4]. The positive nutritional features of edible insects are the presence of high quantities of proteins, essential and non-essential amino acids, lipids, fibers, vitamins, and minerals [4, 5]. Roncolini et al [4] conducted a study to evaluate the use of lesser mealworm powder to replace a part of wheat flour as a means to enhance the protein and mineral content of crunchy snacks. The rearing substrate can modulate the insect nutritional quality [3]. Production efficiencies, and protein quality are influenced by substrates used to feed the insects and depend on entomological species raised and rearing conditions [8, 9]

Methods

Results

Discussion

Conclusion