Cheryan M
Crit Rev Food Sci Nutr. 1980;13(4):297-335. doi: 10.1080/10408398009527293.
Phytic acid is present in many plant systems, constituting about 1 to 5% by weight of many cereals and legumes. Concern about its presence in food arises from evidence that it decreases the bioavailability of many essential minerals by interacting with multivalent cations and/or proteins to form complexes that may be insoluble or otherwise unavailable under physiologic conditions. The precise structure of phytic acid and its salts is still a matter of controversy and lack of a good method of analysis is also a problem. It forms fairly stable chelates with almost all multivalent cations which are insoluble about pH 6 to 7, although pH, type, and concentration of cation have a tremendous influence on their solubility characteristics. In addition, at low pH and low cation concentration, phytate-protein complexes are formed due to direct electrostatic interaction, while at pH > 6 to 7, a ternary phytic acid-mineral-protein complex is formed which dissociates at high Na+ concentrations. These complexes appear to be responsible for the decreased bioavailability of the complexed minerals and are also more resistant to proteolytic digestion at low pH. Development of methods for producing low-phytate food products must take into account the nature and extent of the interactions between phytic acid and other food components. Simple mechanical treatment, such as milling, is useful for those seeds in which phytic acid tends to be localized in specific regions. Enzyme treatment, either directly with phytase or indirectly through the action of microorganisms, such as yeast during breadmaking, is quite effective, provided pH and other environmental conditions are favorable. It is also possible to produce low-phytate products by taking advantage of some specific interactions. For example, adjustment of pH and/or ionic strength so as to dissociate phytate-protein complexes and then using centrifugation or ultrafiltration (UF) has been shown to be useful. Phytic acid can also influence certain functional properties such as pH-solubility profiles of the proteins and the cookability of the seeds.
植酸存在于许多植物系统中，在许多谷物和豆类中占其重量的约1%至5%。人们对其在食物中的存在表示关注，因为有证据表明，它通过与多价阳离子和/或蛋白质相互作用形成复合物，从而降低了许多必需矿物质的生物利用率，这些复合物在生理条件下可能不溶或无法利用。植酸及其盐的精确结构仍存在争议，而且缺乏良好的分析方法也是一个问题。它与几乎所有的多价阳离子形成相当稳定的螯合物，这些螯合物在pH值为6至7时不溶，尽管阳离子的pH值、类型和浓度对其溶解性特征有极大影响。此外，在低pH值和低阳离子浓度下，由于直接的静电相互作用会形成肌醇六磷酸 - 蛋白质复合物，而在pH值>6至7时，会形成三元肌醇六磷酸 - 矿物质 - 蛋白质复合物，该复合物在高Na + 浓度下会解离。这些复合物似乎是导致复合矿物质生物利用率降低的原因，并且在低pH值下对蛋白水解消化也更具抗性。生产低植酸食品的方法开发必须考虑植酸与其他食品成分之间相互作用的性质和程度。简单的机械处理，如研磨，对那些植酸倾向于集中在特定区域的种子很有用。酶处理，无论是直接使用植酸酶还是通过微生物（如面包制作过程中的酵母）的作用间接进行，只要pH值和其他环境条件有利，都是相当有效的。利用一些特定的相互作用也有可能生产低植酸产品。例如，调节pH值和/或离子强度以解离肌醇六磷酸 - 蛋白质复合物，然后使用离心或超滤（UF）已被证明是有用的。植酸还可以影响某些功能特性，如蛋白质的pH值 - 溶解度曲线和种子的可煮性。
