植酸酶的激活及其催化植酸钠水解提取肌醇

以脱脂米糠为原料提取肌醇,用离子交换树脂吸附植酸,再用NaOH洗脱,得到植酸钠溶液,采用植酸酶阳离子激活提高酶活后催化植酸钠水解,水解液最后用CaCO3溶液破坏水解平衡的原理辅助水解,从而制得得率高达11.5％的肌醇.     

植酸酶的激活及其催化植酸钠水解提取肌醇

以脱脂米糠为原料提取肌醇,用离子交换树脂吸附植酸,再用NaOH洗脱,得到植酸钠溶液,采用植酸酶阳离子激活提高酶活后催化植酸钠水解,水解液最后用CaCO3溶液破坏水解平衡的原理辅助水解,从而制得得率高达11.5%的肌醇。     

生物酶水解植酸钙提取肌醇研究

确定了多组分溶液中肌醇的检测技术和仪器分析方法。研究了反应温度、时间、ｐＨ、加酶量等因素对植酸钙酶催化反应过程的影响，确定了植酸钙酶催化反应过程的工艺条件，提出了酶法提取肌醇的新工艺。     

微波辐射水解植酸快速制备肌醇的研究

采用微波辐射法水解植酸制备肌醇，缩短了水解时间和获得了较好的产率。用正交实验法确定了制备肌醇的最佳水解条件。提出了分析水解度的方法和探讨了植酸微波水解机理。     

植酸水解制取肌醇的条件与机理

在常压及高沸点溶剂多元醇存在下,新工艺植酸催化水解制取肌醇的反应条件是:植酸浓度(水酯比)55—65％(W/W,下同),温度130—150℃,水解时间3—4小时,水解平衡转化率可达96％。并对反应机理进行了分析。     

肌醇生产工艺研究新进展

本文依照不同的水解反应物将肌醇生产大致分为三类，分别讨论了三种不同生产方法的研究进展。并对今后肌醇生产的发展提出展望。     

内源性植酸酶对大豆乳、面团等食品中植酸的作用

天然植物食品中含有内源性植酸酶,一定条件下可以催化其中的植酸水解。实验表明,内源性植酸酶在对豆乳中的植酸进行水解时,45℃下24 h后植酸磷水解率达到了28.1%;内源性植酸酶在对面团中的植酸水解时,45℃下4 h后植酸磷水解率达到27.9%,而添加一定量酵母于面团中进行发酵处理,面团中植酸磷的水解率可以增至40.9%。所以,食品中内源性植酸酶对植酸的水解作用是存在的,但程度有限。     

植酸肌醇联产工艺的可行性研究

对从米糠中提取植酸和肌醇的工艺条件、工艺流程进行了改进和优化。探讨了酸浸时间、酸浸次数、液料比、静置时间等因素对产品产量和质量的影响,得出了优化的工艺条件,从实际生产的角度对工艺流程的改进做了进一步研究。     

植酸肌醇联产工艺的可行性研究

对从米糠中提取植酸和肌醇的工艺条件、工艺流程进行了改进和优化。探讨了酸浸时间、酸浸次数、液料比、静置时间等因素对产品产量和质量的影响,得出了优化的工艺条件,从实际生产的角度对工艺流程的改进做了进一步研究。      

酶法水解大豆中植酸的研究

探讨了植酸酶在不同酶解条件(pH值、温度、时间、加酶量)下对大豆抗营养因子——植酸盐的水解作用。研究结果表明,适宜的酶解条件为:温度37℃,酶加量3750U/kg豆粉,酶解时间45min,pH值6.1。在此条件下,酶解后每克大豆粉游离无机磷的含量增加208μmol(约占总磷的66.4%);可溶性金属离子Zn2 、Ca2 、Mg2 和Fe2 的释放量分别达到73.0%、69.6%、62.9%和23.7%;植酸的降解率达到56.6%。结论:酶法水解大豆中植酸可以显著提高大豆的营养效价。     

Phytase activity and degradation of phytic acid during rye bread making

Changes in phytic acid content, activity of phytase and α-amylase in rye breads were determined during rye bread making. The activity of phytase is highest in grain and flour whereas the activity in the sourdoughs is almost the half of the activity in the flour. The activity was unchanged in the dough after mixing and proofing. Degradation of phytic acid (IP6) into lower inositol phosphates and free phosphate is almost completed during the production of rye bread with long fermentation time whereas the degradation is less completed when whole grains are included in the recipe. In rye bread made from milled rye (DB00), 99% of IP6 is degraded and IP3 becomes the dominating inositol phosphate in this bread type presumably resulting in a high level of bioavailable minerals. In rye bread made with 30% grains (SB30), 94% of the IP6 content was reduced with IP4 and IP3 being the dominating lower inositol phosphates. In rye bread made with 50% whole grains (KB50) the degradation of IP6 was 82%, and the three inositol phosphates IP5, IP4 and IP3 were found in equal amount in this bread type. Due to significant amounts of phytic acid and remaining IP5, some of the minerals might not be available for human absorption after consumption of this bread type.     

三磷酸肌醇的研究进展

三磷酸肌醇（简称为IP3）具有多种同分异构体，不同结构的IP3具有不同的功能。有的异构体对多种疾病具有预防和减轻病症的疗效，有的能消除或减轻一些药物对人和动物产生的副作用，有的异构体对动植物细胞内的信息传递具有非常重要的作用等。不同IP3的制备方法不同，利用光谱和高压液相色变方法可以检测其含量，利用核磁共振谱分析方法可以鉴别不同异构体的结构。米糠和玉米浸泡水中含有丰富的植酸盐，它是制备IP3的最好原料。     

植酸酶在玉米原料酒精生产中的应用

植酸酶分解玉米原料中的植酸磷，释放出无机磷，促进酵母发育及代谢。实验结果表明，发酵时添加植酸酶，酒精含量平均提高0．8％(v／v)，原料出酒率平均提高1．6％，即生产1t酒精可节省140kg玉米，效益非常可观。     

植酸对柑桔中抗坏血酸（L—ASA）的保护作用

植酸的浓度在０．１％以上，ｐＨ３．５～１０之间时对维生素Ｃ有较好的保护作用，它能抑制金属离子对维生素Ｃ的氧化催化作用，而且在Ｈ２Ｏ２和金属离子存在下对Ｈ２Ｏ２的氧化有抑制作用，尤其是较完全地抑制铁离子存在的Ｈ２Ｏ２的氧化作用，柠檬酸缓冲液能降低植酸对金属离子氧化催化作用的抑制。     

Phytase and Citric Acid Supplementation in Whole-Wheat Bread Improves Phytate-phosphorus Release and Iron Dialyzability

ABSTRACT Conditions were established for maximizing phytate breakdown in whole‐wheat flour (wwf) during bread baking and for assessing the effects of dephytinization on dialyzability of intrinsic and added iron in the bread. Three different sources of phytase (Aspergillus niger, A. fumigatus, and Escherichia coli) with various levels of citric acid (0 to 6.25 g/kg wwf) were used. Supplementing citric acid at 6.25 g/kg wwf enhanced phytate degradation catalyzed by intrinsic phytase from 42% in the untreated bread to 69% (P < 0.05). Supplementation of microbial phytase (285 units/kg) plus 3.125 or 6.25 g citric acid/kg wwf further enhanced phytate reduction up to 85%. Compared with the untreated bread, citric acid alone and the combination of citric acid and phytase enhanced total iron dialyzability by 12‐ and 15‐fold, respectively, while the combination of phytase, citric acid, and ascorbic acid improved total iron dialyzability in the mixture by 24‐fold.     

丝织品人工老化水解实验研究

模拟丝织品文物出土前在水中浸泡的状况,对植物染色的桑蚕丝绸进行水解老化实验,研究潮湿环境对丝织品文物老化所产生的影响,探讨染色丝绸的色彩在去离子水长期浸泡情况下的变化规律。研究涉及了6种丝绸样品:白色丝绸、红色丝绸、黄色丝绸、茶色丝绸、蓝色丝绸和黑色丝绸。通过对实验样品的色差分析,发现了各种颜色的丝绸样品在水解老化时的色泽变化规律,可以作为确定彩色丝织品文物保存环境的参考。     

Effects of sodium chloride on the degradation of hexoses and the hydrolysis of sucrose in subcritical water

The effects of sodium chloride on the degradation of hexoses at 220 °C and the hydrolysis of sucrose at 170 °C in subcritical water were examined. Sodium chloride accelerated the degradation at 220 °C of any hexose, especially the degradation of galactose which significantly accelerated depending on the sodium chloride concentration. On the other hand, the hydrolysis of sucrose at 170 °C was not affected by sodium chloride.