Phytase
Phytase is an enzyme that can break down the undigestible phytic acid (phytate) part that is found in grains and oil seeds and thus release digestible iron, phosphorus and calcium.
Phytase plays a significant role in human nutrition, especially of iron, because it releases minerals in bread and grains, allowing assimilation in the human digestive system. It is also an important supplement for domestic pigs.[1]
Soaking whole grains such as brown rice or barley overnight for about 12 hours in room temperature (or slightly warmer) water allows the phytase enzyme to remove the phytic acid from the grain coverings, making them more digestible. By the next morning, tiny dots in the water will indicate that the enzyme has done its job of leaching out the phytates from the grain coverings. Grains soaked in this manner may then be cooked in their soak water, which may contain other nutrients from the grains.
Phytate molecules are too large to pass across the stomach lining and into the bloodstream. The molecules are also unaffected by digestive juices and colonic bacteria, so are lost in the excreta.
Use
A loaf of bread made using a home bread machine or the Chorleywood Bread Process was not allowed time for the phytase enzyme to break the phytic acid bonding with mineral constituents in the grain. Traditional bread making produces a mix that spends 8-12 hours or more in the form of a dough, before baking. This time is required for the phytase enzymes to release the mineral constituents in the flour. (All grains are similar, so this applies to rye, wheat or corn bread, etc.)
Phytase is used as an animal feed supplement to enhance the nutritive value of plant material by liberation of inorganic phosphate from phytic acid (myo-inositol hexakisphosphate) and, thereby, to reduce environmental phosphorus pollution.
Production
Phytase can be purified from transgenic microbes. Phytase has been produced recently in transgenic canola, alfalfa and rice plants. Phytase can also be massively produced through cellulosic biomass fermentation using genetically modified (GM) yeast.
References
- ↑ Jacela JY, DeRouchey JM, Tokach MD, et al. (2010), "Feed additives for swine: Fact sheets – high dietary levels of copper and zinc for young pigs, and phytase", J Swine Health Prod. 18 (2): 87–91.