Using Near-Infrared (NIR) Spectroscopy and Mid-Infrared (MIR) Spectroscopy to Detect the Cricket Powder in Plant Flours

Near-infrared (NIR) and mid-infrared (MIR) spectroscopy can be used to determine the level of adulteration of cricket powder (CKF) when mixed with commercial chickpea flour (CPF) and flaxseed meal flour (FxMF), according to a recent study published in Sensors (1).

Edible insects have garnered significant attention as a sustainable and nutritious alternative for both human and animal consumption. The Covid-19 pandemic highlighted the growing food insecurity many people face globally (2). It was thought that edible insects, because of their high nutritional value, could be used to supplement the current food supply if food scarcity becomes a greater problem worldwide (2).

Domestic cricket powder. Sketch art for artist creativity and inspiration. Generated with AI. | Image Credit: © ReisMedia - stock.adobe.com

This also includes using insects in plant-based protein flours for added nutrition. A recent study from the University of Queensland in Brisbane, Australia, explored this topic by evaluating the effectiveness of near-infrared (NIR) and mid-infrared (MIR) spectroscopy in detecting and quantifying the adulteration of cricket powder in plant-based protein flours (1).

The research focused on CKF and its potential adulteration when mixed with commercial CPF and FxMF. The study tested various ratios of CKF to plant flours ranging from 95:5% to 50:50% (1). By employing advanced spectroscopic techniques, the researchers aimed to develop a rapid and cost-effective method for monitoring the purity of these protein mixtures (1).

Using an attenuated total reflectance (ATR) MIR instrument and a Fourier transform (FT) NIR instrument, the team analyzed the mixture samples. The partial least squares (PLS) cross-validation statistics revealed encouraging results (1). For the MIR spectra, the coefficient of determination (R²CV) and the standard error in cross-validation (SECV) were 0.94 and 6.68%, 0.91 and 8.04%, and 0.92 and 4.33% for the combined samples (ALL), CPF vs. CKF, and FxMF vs. CKF mixtures, respectively (1). In contrast, the NIR results showed even higher accuracy with R²CV and SECV values of 0.95 and 3.16%, 0.98 and 1.74%, and 0.94 and 3.27% for the same sample sets (1).

In their study, the research team highlighted the matrix effect, which is the influence of the type of flour on the PLS regression outcomes (1). Differences in absorbance values at specific wavenumbers in the NIR range allowed the classification of CKF presence in the mixtures (1). These notes confirm what the researchers sought to determine, which was that MIR and NIR spectroscopy can be preliminary screening tools to detect cricket powder adulteration.

Current methods in food analysis, such as high-performance liquid chromatography (HPLC), gas chromatography–mass spectrometry (GC–MS), or DNA analyses, are popular techniques, but are also time-consuming and expensive. The researchers demonstrated that NIR and MIR can be used for the initial screening, saving the more expensive techniques for suspect samples (1).

The study emphasizes that the implementation of these spectroscopy methods can significantly mitigate the risk of food fraud and ensure the safety and security of food ingredients. Stakeholders across the food supply chain, from manufacturers to consumers, stand to benefit from the increased reliability and economic efficiency of this approach (1).

However, the scientists caution that before these techniques can be widely adopted, further research is necessary to develop reliable models. This involves including a broader range of samples and different types of powders and flours for thorough validation.

Whether crickets become more pervasive as an alternative protein source remains to be seen. However, the findings showcase the potential of vibrational spectroscopy in routine food analysis and quality control, paving the way for more sophisticated and accessible monitoring tools in the food industry.

References

(1) Alagappan, S.; Ma, S.; Nastasi, J. R.; et al. Evaluating the Use of Vibrational Spectroscopy to Detect the Level of Adulteration of Cricket Powder in Plant Flours: The Effect of the Matrix. Sensors 2024, 24 (3), 924. DOI: 10.3390/s24030924

(2) Liceaga, A. M. Edible Insects, A Valuable Protein Source From Ancient to Modern Times. Adv. Food Nutr. Res. 2022, 101, 129–152. DOI: 10.1016/bs.afnr.2022.04.002