Improvement of calcium solubility and bioavailability of calcium-fortified soymilk containing Lactobacillus acidophilus, L. casei and L. plantarum

A high intake of dietary calcium through out life helps reduce the risk of osteoporosis. The amount of calcium available to the body depends not only on how much is consumed, but on the body’s ability to absorb calcium and retain it. As soymilk contains significantly less calcium than cow’s milk; calcium is often added as a fortificant, but it is unclear whether this added calcium is well absorbed. Soybeans, like other legumes contain myo-inositol hexaphosphate (IP6), also known as phytate, that can chelate calcium inhibiting its absorption. Fermenting soy milk with certain lactic acid bacteria can reduce the amount of IP6. These microorganisms produce the enzyme, phytase which hydrolyses IP6 to its lower IPs including; myo-inositol pentaphosphate (IP5), IP4, IP3 and IP1. Furthermore, fermenting soy milk with lactic acid bacteria increases the conversion of isoflavones to the biologically active aglycone form. These biologically active soy isoflavones have important actions in decreasing bone loss.