Butterfat

Butterfat or milkfat  is the fatty portion of milk. Milk and cream are often sold according to the amount of butterfat they contain.

Composition
The fatty acids of butterfat are typically composed as follows (by mass fraction):


 * Saturated fatty acids:
 * Palmitic acid: 31%
 * Myristic acid: 12%
 * Stearic acid: 11%
 * Lower (at most 12 carbon atoms) saturated fatty acids: 11%
 * pentadecanoic acid and heptadecanoic acid: traces
 * TriglycerideDairyButter.png (a fat) derived from fatty acids such as myristic, palmitic, and oleic acids.]]


 * Unsaturated fatty acids:
 * Oleic acid: 24%
 * Palmitoleic acid: 4%
 * Linoleic acid: 3%
 * alpha-Linolenic acid: 1%

Fatty acids vs triglycerides
As shown above, the composition of fats in milk is usually discussed in terms of the fatty acids. Fatty acids do not occur as such in milk (and rarely in any food). Instead, they are incorporated into compounds called triglycerides.

U.S. Standards
In the U.S., there are federal standards for butterfat content of dairy products. Commercial products generally contain the minimum legal amount of fat.


 * Milks
 * Skim milk contains less than 0.5% fat, typically 0.1%
 * Lowfat milk contains between 0.5–2% fat; 1% and 2% varieties are widely marketed
 * Whole milk contains at least 3.25% fat


 * Cheeses
 * Dry curd and nonfat cottage cheese contain less than 0.5% fat
 * Lowfat cottage cheese contains 0.5–2% fat
 * Cottage cheese contains at least 4% fat
 * Swiss cheese contains at least 43% fat relative to the total solids
 * Cheddar cheese contains at least 50% fat relative to the total solids


 * Frozen desserts
 * sherbet contains 1–2% fat
 * Lowfat ice cream, also called ice milk, contains no more than 2.6% fat
 * Ice cream contains at least 10% fat
 * Frozen custard, like ice cream, contains at least 10% fat, but it also must contain at least 1.4% egg yolk solids


 * Creams
 * Half and half contains 10.5–18% fat
 * Light cream and sour cream contain 18–30% fat
 * Light whipping cream (often called simply "whipping cream") contains 30–36% fat
 * Heavy cream contains a minimum of 36% fat
 * Manufacturer's cream (not federally regulated) contains 40% fat


 * Butter (including whipped butter) contains at least 80% fat