Acoustic Damping as a Low-Cost Sensor for Wheat Flour Quality Evaluation

Food adulteration in wheat flour continues to pose a significant threat to public health and the integrity of the food supply, especially in regions lacking access to advanced analytical infrastructure. Conventional detection methods, while accurate, are often expensive, laboratory dependent, and unsuitable for field deployment. This work introduces a simple, portable setup comprising a speaker, a microphone, and an open-source application that detects wheat adulteration via acoustic damping. In addition, we have also assessed complementary detection techniques such as visual inspection, dough drying rate analysis, and compression stress–strain testing. Wheat flour is mixed with two adulterants, talc and Maida (refined wheat flour), at predetermined proportions (5% and 10% by weight), with consistent water addition during dough preparation to ensure uniform hydration. Acoustic damping measurements show a significant increase in sound attenuation, with over 90% energy dissipation attributable to adulterants, regardless of the adulterant type or wettability. However, this method cannot determine the specific type of adulterant. Visual inspection effectively differentiates adulterated samples, particularly between talc and Maida, based on discernible differences in color and texture. Compression testing revealed increased stiffness in adulterated doughs relative to pure samples, whereas drying rate analysis revealed variations related to the water-absorbing or hydrophobic properties of the adulterants.