Global consumption of quinoa flour has increased in recent years. It is a relatively high value product and potential adulterants (flours of cheaper grains or seeds) are visually identical. Adulteration is a risk. In this study (here – open access) portable hyperspectral imaging in the visible near-infrared (VNIR) spectral range (400–1000 nm) was applied as a rapid tool. The concept was proven using quinoa flour adulterated with wheat, rice, soybean, and corn in the range of 0–98% with 2% increments. Partial least squares regression (PLSR) models were developed, and the best discriminatory model selected. The model was improved by selecting only 13 wavelengths, rather than using the full spectrum, using bootstrapping soft shrinkage. A visualization map was also generated to predict the level of quinoa in the adulterated samples. The study proved the concept of using rapid and portable non-destructive VNIR as a screening tool for quinoa flour adulteration.
Photo cropped from HowToGym on Unsplash
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