Characterization of butter and margarine oil composition using benchtop NMR and FTIR: A comparative study of products from Uzbekistan and Denmark

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 1 H 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 the Uzbek margarines 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 clear compositional contrasts 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. Benchtop NMR also enabled detection of additives, such as stanol esters and sorbic acid, in several butter samples. Overall, this work demonstrates a 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. • Rapid workflow for core quality traits of edible oil using benchtop ¹H NMR and FTIR • Some margarines and most butters exceed the 2% TFA limit in edible oils • Benchtop ¹H NMR detected stanol esters and sorbic acid in butter, not margarine • Major fatty acids differ between margarine and butter in both countries