Effect Of Phytase And Inositol On The Biochemistry And Brewing Characteristics Of Malt

Phytic acid is in the presence of the form of phytic acid chelate salt in barley and the average content of phytic acid is1%in barley dry seeds. It is the main storage form of phosphorus and inositol and it is the "vault" of many metal ions and high-energy phosphate groups. Phytic acid is an important anti-nutritional factor which has strong complexing ability on the vast majority of metal ions. For these reasons, the experimental will use phytase as the Malting additives to promote barley phytate hydrolysis and release nutrients to improve the quality of malt.The reasons for the change of the enzyme actibity were theoretical ananlyzed by HPLC and ICP-AES, and study on the effect of phytase and inositol on the biochemical characteristics of malt.Experiments show that:(1) Compared with the original barley, the group processed by phytase is more powerful in hydrolase. What’s more, the content of metal ions(K+、Na+、Ca2+、Mg2+、Zn2+), inositol and gibberellin increases while the ABA content decreases. Because of phytase’s entering into the body of barley through the micropyle with the water during steeping stage, the phytate stored there is hydrolyzed and releases metal ions, inositol and phosphate. Therefore, the metal ion content increases which activates the hydrolase and improve the hydrolase activity. On the other hand, phytase can not only contribute to the secretion of GA3which can promote the vitality of internal hydrolase but also decreases the ABA content to make barley seeds break the sleep state quickly.(2) Compared with the original barley, the group processed by inositol is more powerful in hydrolase and the content of metal ions (K+, Na+, Ca2+, Mg2+, Zn2+) and free phosphate ions increases. Add the inositol exogenously can promote the release of barley metal ion and improve their hydrolase activity. In addition, inositol can activate the internal phytase and other hydrolase in advance.(3) The malt processed by phytase or inositol as the additive is superior to the original group in the aspects of the solubility (turbidity, libraries, value, beta-glucan), leaching rate and saccharification power. Therefore, the usage of phytase or inositol as malting additive can improve some indicators of malt and contribute to the malt dissolving, shorten the cycle of malting, and improve economic efficiency.