Structure of atriglyceride containing myristic, palmitic, and oleic acid
Butterfat is mainly composed oftriglycerides. Each triglyceride contains threefatty acids. Butterfat triglycerides contain the following amounts of fatty acids (by mass fraction):[1][2][3]
black: Saturated;grey: Monounsaturated;green: Polyunsaturated;blue: Trans
Butterfat contains about 3%trans fat, which is slightly less than 0.5 grams perUS tablespoon.[3] Trans fats occur naturally in meat and milk fromruminants. The predominant kind of trans fat found in milk isvaccenic fatty acid. Trans fats may be also found in some industrially produced foods, such asshortenings obtained by hydrogenation ofvegetable oils. In light of recognized scientific evidence, nutritional authorities consider all trans fats equally harmful for health and recommend that their consumption be reduced to trace amounts.[4][5][6][7][8]However, two Canadian studies have shown thatvaccenic acid could be beneficial compared to vegetableshortenings containing trans fats, or a mixture of porklard and soy fat, by lowering totalLDL and triglyceride levels.[9][10][11][12][13] A study by the US Department of Agriculture showed that vaccenic acid raises bothHDL and LDL cholesterol, whereas industrial trans fats only raise LDL with no beneficial effect on HDL.[14]
Milk fatty acids, length, and position on glycerol (1, 2, 3)[15]
In theU.S., there are federal standards[16] for butterfat content ofdairy products.[17][18][19][20] Many other countries also have standards for minimum fat levels in dairy products. Commercial products generally contain the minimum legal amount of fat with any excess being removed to make cream, a valuable commodity.
^Wang Y, Jacome-Sosa MM, Vine DF, Proctor SD (20 May 2010). "Beneficial effects of vaccenic acid on postprandial lipid metabolism and dyslipidemia: Impact of natural trans-fats to improve CVD risk".Lipid Technology.22 (5):103–106.doi:10.1002/lite.201000016.
^David J. Baer, PhD. US Department of Agriculture, Agricultural Research Service, Beltsville Human Nutrition Research Laboratory.New Findings on Dairy Trans Fat and Heart Disease Risk, IDF World Dairy Summit 2010, 8–11 November 2010. Auckland, New Zealand
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