Edible insects have been recognised as an alternative food or feed ingredient due to their protein value for both humans and domestic animals. The objective of this study was to evaluate the ability of both near- (NIR) and mid-infrared (MIR) spectroscopy to identify and quantify the level of adulteration of cricket powder added into two plant proteins: chickpea and flaxseed meal flour. Cricket flour (CKF) was added to either commercial chickpea (CPF) or flaxseed meal flour (FxMF) at different ratios of 95:5% w/w, 90:10% w/w, 85:15% w/w, 80:20% w/w, 75:25% w/w, 70:30% w/w, 65:35% w/w, 60:40% w/w, or 50:50% w/w. The mixture samples were analysed using an attenuated total reflectance (ATR) MIR instrument and a Fourier transform (FT) NIR instrument. The partial least squares (PLS) cross-validation statistics based on the MIR spectra showed that 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 ALL, CPF vs. CKF, and FxMF vs. CKF mixtures, respectively. The results based on NIR showed that the cross-validation statistics R2CV and SECV were 0.95 and 3.16%, 0.98 and 1.74%, and 0.94 and 3.27% using all the samples analyzed together (ALL), the CPF vs. CKF mixture, and the FxMF vs. CKF mixture, respectively. The results of this study showed the effect of the matrix (type of flour) on the PLS-DA data in both the classification results and the PLS loadings used by the models. The different combination of flours (mixtures) showed differences in the absorbance values at specific wavenumbers in the NIR range that can be used to classify the presence of CKF. Research in this field is valuable in advancing the application of vibrational spectroscopy as routine tools in food analysis and quality control.
Edible insects have been evaluated as an alternative and sustainable source of protein because of their nutritive and functional properties for humans and domestic animals. The objective of this study was to assess the use of chemometric [principal component analysis (PCA) and partial least squares (PLS)] combined with Rapid Visco Analyser (RVA) profiles to evaluate the addition of cricket powder (CKP) to chickpea (CPF) and flaxseed (FxF) flours. The results of this study showed that the addition of CKP powder to both CPF and FxF flours affects the pasting properties of the samples; in particular, a reduction in the peak (PV) and final viscosity (FV) was observed. The use of chemometric data techniques such as PCA and PLS regression allowed for a better interpretation of the RVA profiles. Both PCA and PLS regression allowed to qualitative and quantitatively identify the addition level of CKP powder to CPF and FxF flour samples. Differences in the PLS loadings associated with the RVA profile due to the addition of cricket powder were observed. The development of these methodologies will provide researchers and the food industry with better tools to both improve and monitor the quality of ingredients with functional properties as well as to further understand the use of insects as alternative sources of protein.