Characterization of butter and margarine oil composition using benchtop NMR and FTIR: A comparative study of products from Uzbekistan and Denmark
Abstract
This study presents an optimized workflow for rapid quantification of core quality traits in edible oils, including trans-fatty acids (TFA), saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), and selected additives, by combining 80 MHz benchtop 1H NMR and Fourier transform infrared (FTIR) spectroscopy. Seventy commercial margarine and butter products from Denmark and Uzbekistan were analyzed. FTIR-based TFA quantification showed that nearly 50% of margarine samples from Uzbekistan exceeded the 2% regulatory threshold, while all Danish samples remained below 1.3%. Butter, which naturally contains rumen-derived TFA, exhibited greater variability (up to 6%) but no country-specific differences. NMR analysis revealed significant differences in SFA, MUFA, and PUFA content between butters and margarines, and between the same product types across the two countries. Butter consistently contained more SFA and less PUFA than margarine, while MUFA and PUFA showed the greatest geographical variation. In addition, benchtop NMR enabled detection of additives, such as stanol esters and sorbic acid, in varying amounts in butter samples. Overall, this work demonstrates an optimized workflow based on green analytical technologies that provides robust chemical insights into core quality traits of edible oils, enabling efficient monitoring in both research and quality control laboratories.