.
BS act as vehicles for fat soluble
products owing to the formation of micelles/aggregates of BS with
phospholipids.facilitating the solubilisation and transport of fat soluble nutrients to the
mucosa of the small intestinesurface activity having a strong affinity for hydrophobic phases (oils,
fats, and lipids)BS self-assemble in solution
forming micelles. The first evidence of the association of BS to form
micellesadsorb onto and remove other materials such as proteins and
emulsifiers from the lipid surface lipase and its co-
factor co-lipase to adsorb onto the lipid surface and instigate lipolysis.
BS are steroidal detergents biosynthesized from cholesterol in the
liver and stored in the gall bladder.]. BS have an ability to solubilise polar lipids during intestinal
digestion, which is essential for effective absorption of dietary lipids by
the intestinal epithelium. Whilst large amounts of BS are secreted into
the small intestine very little is excreted from the body as over 95% is
reabsorbed in the ileum and returned to the liver for recirculation]. BS serve a number of different functions
from antibacterial defense [19] to denaturation of protein prior to
proteolysis [20] and interfacial conditioning prior to lipolysis and
product transport in mixed micelles
BS do not have well defined tail and head groups but exhibit
planar polarity. Bile acids comprise two connecting units, a rigid steroid
backbone with a hydrophobic and a hydrophilic face to which a flexible
aliphatic tail is attached
. The most abundant BS in humans are cholate,
chenodeoxicholate and deoxicholate.Because of the amphiphilic nature of BS, they self-assemble when
in an aqueous environment forming micelles.BS micelles are very dynamic and can vary from
oblate to spherical and prolate
When the partially digested food moves from the stomach
into the small intestine, it is mixed with bile and pancreatic secretions in
the duodenum forming an emulsion stabilised by bio-surfactants.
BS are capable of
displacing proteins from oil–water interfaces in emulsions.The protein
network is severely disrupted by the addition of BS and the surface
dilatationalmodulus of the protein network decreases sharply until they
reached practically null values, similar to that of BS