Molecular approach for insect detection in feed and food: the case of Gryllodes sigillatus

Abstract

The production of insects on an industrial scale has attracted the attention of the research and agricultural industry as novel protein sources. To detect the presence of Gryllodes sigillatus (GS) in feed and food, a real-time PCR method based on the mitochondrial cytochrome b (CYB) gene is proposed by this study. Forty DNA samples of animal and plant origin were used to confirm the specificity of the qPCR system. The detection method's performance was evaluated on different processed GS matrices including native GS (UnGS) and different commercial products: crunchy roasted samples (RoGS), insect meal mixtures (ACGS) and energetic snacks containing GS (GSS). Data on sequencing were aligned with the reference gene to confirm the PCR products. The regression curve (y = −3.394 x + 42.521; R 2 = 0.994, d.f. 14) between C t values and Log DNA concentrations of Gryllodes sigillatus resulted in an efficiency of 96.4%. The severity of the technological processing treatments and the matrix structure affected the intensity of the PCR signal with the same amount of insect DNA as observed by different y-intercepts of the three-regression lines for RoGS, ACGS, and GSS. The real-time PCR method resulted in robust and sensitive outcomes able to detect low amounts of GS DNA (5 g/100 g) in a complex matrix, making it suitable for detecting the presence or absence of labeled Gryllodes sigillatus material both in feed and food.

Mitochondrial genome characterization of Gryllodes sigillatus (Orthoptera: Gryllidae) and its phylogenetic implications

“… 2019 ; Daniso et al. 2020 ). G. sigillatus was first described in 1869 and then classified into different genera many times (Otte 2006 ).…”

“…Gryllodes sigillatus (Walker), a field cricket, also known as tropical house cricket, belongs to the Family Gryllidae with a wide distribution throughout the world (Otte 2006). It is a pest but sometimes also kept as a pet or animal feed in addition to a promising protein source for human diet (Ma et al 2019;Daniso et al 2020). G. sigillatus was first described in 1869 and then classified into different genera many times (Otte 2006).…”

LC-MS-based detection of silkworm pupae in feed with and without prior immunoaffinity enrichment

“…This prioritisation may be justified by considering these species as of high commercial relevance, increasingly available at relatively low cost and hence potentially providing economical margins high enough to allure feed fraud. Thus, targeted, end-point PCR methods with sensitivities down to 0.01% (w/w) insect powder in feed or food matrix are available for A. domesticus (Garino et al, 2021;Köppel et al, 2019), G. sigilatus (Daniso et al, 2020b), H. illucens (Marien et al, 2018;Zagon et al, 2018), T. molitor (Debode et al, 2017;Köppel et al, 2019), and B. mori (Zarske et al, 2021). Furthermore, a portable genosensor was introduced in 2020 and proved to be able to trace as low as 5% (w/w) H. illucens in aquaculture feed by analysing non-amplified DNA extracts (Daniso et al, 2020a).…”

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

“…This is applied for H. illucens detection in feed ( 36 , 37 ), Oxya chinensis (Thunberg) in food ( 38 ), Bombyx mori L . in food ( 1 ) and feed ( 39 ), and G. sigillatus in food and feed ( 40 ). However, this multicopy characteristic is a disadvantage for quantitation purposes as the copy number per cell will be variable, depending on the considered tissue ( 36 ).…”

“…This facilitates detection in processed food and feed in which the DNA may be degraded, as a mitochondrion contains several copies of its genome, and several mitochondria can be present in a single cell (35). This is applied for H. illucens detection in feed (36,37), Oxya chinensis (Thunberg) in food (38), Bombyx mori L. in food (1) and feed (39), and G. sigillatus in food and feed (40). However, this multicopy characteristic is a disadvantage for quantitation purposes as the copy number per cell will be variable, depending on the considered tissue (36).…”