Identification and quantification of branched-chain fatty acids and odd-chain fatty acids of mammalian milk, dairy products, and vegetable oils using GC/TOF-MS

Branched-chain fatty acids (BCFAs) and odd-chain fatty acids (OCFAs) in mammalian milk, dairy products, and vegetable oils were investigated; 72 fatty acids, including 16 BCFAs and 10 OCFAs, were identified and quantified using GC/TOF-MS. Human milk showed the lowest content of BCFA (0.4% of total FA) and the content in other milk ranged from 2 to 6%, of which ai17:0, i17:0, ai15:0 and i15:0 were most abundant. Differences in the content of OCFA in mammalian milk trended similarly to differences in BCFA content. The molecular species of BCFA in cow milk-derived dairy products were identical, but the content was different, with higher content in fermented dairy products. Apparent differences in BCFA and OCFA composition were found in infant formulas, strongly related to their fat sources. Vegetable oils contained no BCFA and a small amount of OCFA. A scientific basis for further investigation of high-BCFA and OCFA dairy products is provided.