Universidad de Córdoba BIODISPONIBILIDAD MINERAL DE ...

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This effect increase can be explained by the fact that the
fructooligosaccharides can not be degraded by the enzymes present in the
small intestine and therefore arrive practically intact to the colon where they are
fermented by the bacterial flora present there, with developing gases, lactose
and organic acids such as acetate, propionate and butyrate that lower the pH
and make the calcium more soluble (38). These organic acids improve the
absorption of calcium (39-45) in the colon of rats by forming low-charged
mineral complexes (43), thus facilitating the transport by passive diffusion of
these mineral complexes because the cell membranes have low permeability to
highly charged ions like calcium (39). This effect varies according to the
concentrations of calcium and organic acids present in the colon, indicanting a
higher effec to propionate probably because propionate is more lipid soluble
and, therefore, crosses the cell membrane more easily (42, 44).
Another hypothesis to explain the beneficial effect of
fructooligosaccharides as fermentable carbohydrates is the stimulation of
bacterial proliferation in the colon, with a subsequently greater secretion of
phytase, which would enhance the hydrolysis of phytate to phosphate and
inositol (45), preventing the binding of phytate to mineral cations like calcium.
Calcium fortification of foods
The most widely used salts for calcium fortification are calcium
glycerophosphate, calcium gluconate and/or calcium lactate. The type of
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