Chennai: Researchers at the Central University of Tamil Nadu (CUTN) have developed a rapid analytical technique to detect cow ghee adulteration and simultaneously identify and quantify multiple adulterants. The technique could offer a low-cost tool to strengthen food quality checks.The study, published in Food Chemistry, uses Angular Sweep Total Fluorescence Spectroscopy (ASTFS), a fluorescence-based analytical technique. A spectrofluorometer exposes a diluted ghee sample to carefully selected wavelengths of ultraviolet and visible light. Naturally occurring compounds such as vitamins, chlorophyll and proteins then emit fluorescent light. Instead of taking a single reading, the instrument records the fluorescence from multiple angles. This creates a detailed three-dimensional “fingerprint” of the sample’s chemical composition. Advanced statistical models then compare this fingerprint with those of pure and adulterated ghee to identify adulterants and estimate their concentrations.The researchers tested the method on cow ghee adulterated with vanaspati, beef tallow and pork lard. Unlike many existing techniques that only check whether adulteration has occurred, the new approach can simultaneously identify and quantify adulterants in the same sample.“Ghee is a high-value fat produced and widely consumed in India and is therefore highly susceptible to economically motivated adulteration,” said John Prakash, corresponding author. He added that the method “enables reliable and sensitive quantification of adulterants” while also allowing “simultaneous quantification of multiple adulterants.”The team reported that its classification model correctly distinguished pure ghee from samples adulterated with vanaspati, beef tallow and pork lard under the study conditions. It also accurately estimated adulterant concentrations in mixtures containing up to 20% adulterants.The method performed consistently when validated using laboratory-prepared samples and multiple commercial ghee brands.At present, ghee adulteration is detected using laboratory techniques such as gas chromatography and high-performance liquid chromatography, as well as physicochemical tests prescribed by FSSAI. While accurate, these methods can be time-consuming and are less suited for rapid screening of large numbers of samples, the researchers said.According to a release, the analysis requires only about five micrograms of sample. The operational cost is estimated at around ₹50 per test. However, the technique currently relies on specialised laboratory instrumentation.The researchers hope to adapt it into portable handheld devices eventually. Such devices could allow dairy companies and food safety inspectors to carry out rapid on-site screening of ghee for adulteration within minutes.
