Branched chain fatty acids concentrate prepared from butter oil via urea adduction

Abstract

Saturated branched chain fatty acids (BCFA) intake in the US is greater than that of other bioactive fatty acids (FA), yet little information is available on methodologies to concentrate them. We report here the effect of urea‐to‐FA (urea:FA) ratio, adduction time, and temperature on the enrichment of branched chain fatty acids (BCFA) from butter oil. Urea adducts precipitate both saturated and monounsaturated hydrocarbon chains as urea complexes, leaving solubilized polyunsaturated FA and BCFA in the non‐urea adduct fraction (NUA). The optimum urea:FA ratio was found to be 4:1 and the optimum temperature to be 4°C. Adduction time had negligible effect on BCFA enrichment. Anteiso‐15:0 was most enriched across major BCFA under all conditions of temperature, time, and urea:FA ratio studied. In our preferred embodiment, a two‐stage urea adduction procedure applied to hydrolyzed butter oil resulted in an enrichment from <2% BCFA in the starting oil to >11% BCFA, indicating an enrichment factor of >6. The best method has a first stage performed at 4°C and urea:FA ratio of 4:1, and a second stage at 30°C and lower urea:FA ratio (2:1). Overall yield of BCFA in enriched fraction was about 10% of starting BCFA for two stages.Practical applications: BCFA are constituents of the GI tract of healthy newborns and are known to prevent necrotizing enterocolitis. The average per capita BCFA intake of Americans is estimated to be about 220 mg/day from dairy whereas based on the current dietary recommendations of USDA it should be about 400 mg/day from dairy alone with total amounting to 575 mg/day including beef. Using the results of the current study, enriched BCFA concentrates can be prepared to meet the demand.Enrichment in major branched chain fatty acids (BCFA) of butter oil after two stage urea adduction. First stage (NUA‐1) and second stage (NUA‐2) were conducted using 4:1; 4°C 2 h and 2:1, 30°C 2 h of urea‐to‐fatty acids ratio (wt/wt), temperature and time of adduction, respectively.