While a small amount of fat splitting may take place in the stomach, most of the digestion of food fat is carried on in the intestine through the action of intestinal and pancreatic enzyme and of bile.
In human body fat occurs mainly as neutral fat in the form of triglycerides of oleic, palmitic and stearic acid. In addition to neutral fats, fats include phospholipids, cholesterol and its ester. Neutral fats are triglycerides i.e, glycerol combined with three molecules of fatty acids.
The first step of fat digestion begins in the stomach. Lingual lipase secreted from the serous glands of the tongue, and gastric lipase, secreted from the chief cells of the gastric mucosa, digest approximately one third of the dietary triglycerides.
Main digestion of fats is carried out by pancreatic lipase at optimum pH 8 and temperature of 40° C.
Bile salts are helpful and break up the fat droplets, which are emulsified. This emulsification results in increase of the fat surface on which pancreatic lipase can act.
The main path of fat digestion progresses from triglycerides to 1,2-diglycerides, to 2-monoglycerides and finally to free fatty acids and glycerol, perhaps after isomerization to the 1-monoglyceride.
During digestion, exchange of free fatty acids with glyceride fatty acids occurs.
Fats are involved in brain development, inflammatory processes, atherosclerosis, carcinogenesis, aging and cell renewal.
The digestion of fat in human body
