Carotenoid-Fortified Lard Mimics Cow Ghee in Raman Spectra

Abstract

Raman spectroscopy is increasingly used for rapid screening of cow ghee, and several reports treat the Raman peaks of β-carotene at 1006, 1157, and 1520 cm−1 as unique differentiating markers for cow ghee. In this work, carrot-derived carotenoid extract (β-carotene–rich; confirmed qualitatively by HPLC at 453 nm) is added to lard and palm oil (nondairy matrices). Such fortified lard and palm oil exhibited Raman spectra identical to the Raman spectrum of cow ghee. A controlled dose–response dilution series (Master-LC21) further showed a systematic decrease in carotenoid band prominence with increasing lard content, where the lowest detection limit was 0.22 mg g−1 (0.022% w/w) of carotene extract in lard. ATR-FTIR measurements provided only lipid signatures, and the said carotenoid peaks were indiscernible, making Raman an indispensable tool for detecting peaks of β-carotene in the corresponding nondairy matrices. Results demonstrate that reliance on β-carotene Raman peaks for authenticating cow ghee is highly vulnerable to being compromised.