Barley phytases

Malted barley contains a- and P-amylases along with proteases and phytases. Most standardi2ed microbial en2yme preparations for industrial starch conversion contain approximately 100 times more amylase activity than malt. In beermaking, malt is not just valuable for its en2ymes but also for flavor compounds. 

Brearley, C.A., and Hanke, D.E., 1996b, Inositol phosphates in barley (Hordeum vulgare L.) aleurone tissue are sterochemically similar to the products of breakdown of Ins P6 in vitro by wheat bran phytase. Biochem. J. 318 279-286. 

Rodehutscord, M. M. Faust H. Lorenz. Digestibility of phosphorus contained in soybean meal, barley, and different varieties of wheat, without and with supplemental phytase fed to pigs and additivity of digestibility in a wheat-soybean meal diet. /. Anim. Phys. Anim. Nutr. 1996, 75, 40-48. 

Asmar, F. (1 997) Variation in activity of root extracellular phytase between genotypes of barley. Plant and Soil 95, 61-64. 

DIhydroxyacetone Phytase Xylanase enzyme activator, barley malting Potassium gibberellate enzyme activator, brewing Gibberellic acid... 

A phytase has been isolated from the protein bodies of whole, milled, ungerminated barley, and this enzyme appears to be associated with the protein bodies of the aleurone layer (aleurone grains), a known storage site of phytin [141]. There is strong evidence (e.g. in wheat and rice) against the association... 

Studies on the early responses of aleurone layers to GA have shown that a-amy-lase is not the first enzyme to be secreted. Within 5 h of the addition of GA to isolated aleurone layers of barley (cv. Betzes) there is increased secretion into the surrounding medium of several hydrolytic enzymes, including an ATP-ase, phytase, j -glucosidase and phosphomonoesterase, as well as some soluble carbohydrate [96] (probably sucrose). Similar observations were made using GA-treated half-grains of both barley and wheat (the distal embryoless half), although in barley additional enzymes, e.g. an esterase, phosphodiesterase and a-galactosidase were also found to be secreted early [96]. From the limited information available to date it appears that some enzymes which are secreted early after GA addition (e.g. phosphomonoesterase and phosphodiesterase) do so in response to lower concentrations of GA than do the later ones (e.g. a-amylase) [97]. Furthermore, a-amylase and proteinase, which are secreted simultaneously, have identical GA dose-response curves (Fig. 7.5A and B). There are exceptions, however, and further work on more enzymes is required to determine if the sequence of enzyme production by aleurone tissue is related to GA concentration in the cells. 

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