三磷酸肌醇抗油脂氧化性的研究

三磷酸肌醇(IP3)既可以用肌醇经一系列化学反应而合成，也可由植酸经不完全水解后分离而制得。但化学合成方法所得产品成本太高，故一般采用植酸水解法。本文欲研究用微波辐射使植酸水解生产IP3。通过在微波条件下，控制水解条件，当水解度达到50%，将水解混合物通过装有717型强阴离子树脂柱，并用0．05～0．7M盐酸进行线性梯度洗脱，洗脱物分别取样消化，     

植酸酶的激活及其常压催化植酸钠水解提取肌醇的实验研究

在以脱脂米糠为原料提取肌醇的工艺中,用离子交换树脂吸附植酸,再用烧碱洗脱,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。     

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。     

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。     

以菜籽粕为原料研究微量元素氨基酸络合物

以菜籽粕为原料制备微量元素氨基酸络合物配体，通过正交试验确定菜籽油水解的最佳工艺条件是：水解时间８ｈ、硫酸浓度１５％，固液比（Ｗ／Ｖ）１：５，此时氨基酸得率为７３￣７６％，试验表明菜籽粕中芥子甙及其降解产物在水解过程中完全破坏，植酸水解率为２３％，最终用于络合的水解液中植酸未检出。从综合利用出发，通过不同中和工艺的比较及对水解产物成分的分析，设计了较为合理的水解工艺。     

用沉淀法减少植酸钙的含杂量

用沉淀法减少植酸钙的含杂量王小华　（苏州吴越粮油化工有限公司２１５１２８）１引言肌醇是粮油工业综合利用重要产品之一。目前国内肌醇生产的传统工艺是先从米糠制得植酸钙，再由植酸钙经水解而制得肌醇。植酸钙作为肌醇生产的中间产品，其质量对肌醇生产的影响很大，...     

高质量高效率肌醇生产新方法

高质量高效率肌醇生产新方法周秀琴肌醇是国际上热门的健康食品添加剂，又是营养辅助食品和养殖鱼用的饲料添加剂，仅美国年需８００吨。以往肌醇制造一般以米糠等为原料，用酸抽提植酸，将植酸沉淀、分离、加压水解精制、浓缩、结晶而成，但该法得到的植酸纯度低、植酸沉...     

微波技术在玉米芯水解中的应用

针对传统法处理玉米芯制备糖类存在的处理时间长、产生的副反应多、玉米芯的有效利用率低等问题,研究了微波技术对玉米芯水解的情况.以粉碎至1cm左右的玉米芯为原料,以提取木糖的水解收率为指标,分别研究了同液比、微波水解时间和微波功率等因素对微波水解玉米芯制备木糖的水解收率的影响,并对其反应机理进行了解释,通过正交试验优化了微波水解玉米芯制备木糖的工艺参数,得出在固液比1:10、水解时间为9min、微波功率250W时,玉米芯的水解收率可达39.7%,其透光度为42%,干物质含量为6.5%,木糖纯度为65.7%,水解液质量较好,满足了我们的要求,为开发微波技术在玉米芯水解制备木糖工艺中的应用提供了技术参考.     

Fate of phytic acid during bread making

The effect of malt addition and yeast concentration on the hydrolysis of phytic acid during different stages of bread making has been reported. There was a considerable hydrolysis of phytic acid with the addition of yeast and malt. In the breads of S-308 and WL-711 wheat varieties, the loss of phytic phosphorus was 6.6. 8,1; 24.6, 23.0 and 26.6, 27.7% in case of nonyeasted, 1.5% and 3% yeasted dough of whole wheat flour (Atta) respectively. However in white bread, the loss of phytic phosphorus was 14.0 and 18.4; 46.2 and 41.5; 51.7 and 49.4%, in non-yeasted, 1.5% and 3% yeasted doughs of S-308 and WL-711 wheat varieties respectively. A significant loss of phytic acid was observed at a yeast level of 1.5 and 3% and with 0.4% malt addition as compared with the control. Most of the phytic acid was hydrolysed during the fermentation and proofing stages in both types of bread samples.     

植酸提高米曲霉酶活力的机理

米曲霉能分泌植酸酶,如制曲中添加一定量植酸,经植酸酶降解产生肌醇和磷酸,肌醇激活酶系,从而提高米曲霉的酶活力。（一平     

Phytate degradation by Bifidobacterium on whole wheat fermentation

Whole cereal-based products have a beneficial effect on health, but they also contain high levels of phytate, defined as anti-nutrient. The possible use of different strains of bifidobacterial species (B. catenulatum, B. longum and B. breve) with phytate degrading activity as starters in the fermentation process was investigated. Fermentative parameters of doughs (pH, volume, total titrable acidity [TTA] and acetic and lactic acids production) and the hydrolysis profile of the phytic acid were determined during whole wheat dough fermentation. During fermentation in the presence of different bifidobacterial strains, the concentration of phytic acid showed a progressive decrease, leading to a higher release of hydrolysis products than in the control, within short fermentation time. According to the fermentative parameters bifidobacterial strains showed a good adaptation to the dough ecosystem. The range of TTA and lactic acid production was dependent on the strain. Among the tested bifidobacterial strains, those belonging to the species B. breve and B. longum induced a higher hydrolysis of phytic acid with simultaneous production of lower inositol phosphates. In addition, dough containing those strains had high pH and minor acidity than those containing a commercial starter (L. plantarum). Therefore, the tested bifidobacterial strains could be used as breadmaking starters contributing to different acidification degrees and promoting simultaneously the degradation of phytic acid in the whole wheat dough.     

外源酶对糙米中植酸降解的影响

利用外源酶制剂降解糙米中的抗营养因子植酸,以提高糙米营养价值。以植酸降解量为指标,考察pH值、温度、酶作用时间和加酶量对外源植酸酶作用的影响,并考察纤维素酶和果胶酶与植酸酶的协同作用效果。结果显示植酸酶作用的适宜条件为：酶用量0.4U/mL,作用温度50℃,pH5.2,浸泡时间4h;添加纤维素酶和果胶酶能有效促进植酸酶的降解作用,大大提高植酸降解率。外源酶制剂能有效降解糙米中的植酸。     

Determination of phytic acid in rapeseed meal

A new method has been developed for the determination of phytic acid in rapeseed meal based on extraction of the phytate with 15% trichloroacetic acid. After enzymatic hydrolysis with phytase from wheat, the phosphate is determined spectrophotometrically. The method has been applied to a number of varieties of rapeseed. The variation within a variety was nearly as high as within a population of varieties of the same species. The results imply that the phytic acid content of rapeseed is mostly influenced by environmental factors such as the availability of phosphorus in the soil.     

Phytic acid concentration in selected raw materials and analysis of its hydrolysis rate with the use of microbial phytases during the mashing process

Phytic acid present in the raw materials can complex with many compounds and therefore limit their availability to the yeast during the alcoholic fermentation process. An effective utilization of biogenic compounds bound in phytates requires a detailed analysis of the raw materials for their phytic acid content. The aim of this study was to characterize the major technological parameters for selected raw materials used in the distilling industry (maize, rye, wheat and triticale grain) and to determine the phytic acid content and the IP6/total phosphorus ratio. The phytic acid hydrolysis rate during the mashing process, with the use of microbial phytases, was analysed. The highest phytic acid concentrations (2.30 ± 0.20 mg/g dry matter) and the highest IP6/total P (80.42 ± 6.99%) were observed in the maize grain samples. Therefore, further studies on the phytic acid hydrolysis rate with the use of various phytases were conducted for the maize grain. The highest hydrolytic activity was observed for the Phytase 10000L preparation. This was the preparation that hydrolysed the phytic acid completely in up to 90 min. The application of a highly effective phytase, in ethanol production from maize grain, could lead to a more effective utilization of the biogenic compounds during the fermentation process. Copyright © 2015 The Institute of Brewing & Distilling     

Effect of Soda Leavening on Phytic Acid Content and Physical Characteristics of Middle Eastern Breads

The effect of soda (sodium bicarbonate) as a leavening agent on pH, phytic acid hydrolysis and physical quality of a fermentation model system and two popular Middle Eastern breads, Iranian taftoon and Pakistani naan (Arabic) were studied. Supplementing 0.2 and 0.4% soda invariably decreased phytic acid hydrolysis. In sour starter supplemented dough, phytic acid was reduced by 82% after 3 hr. However, when 0.4% soda and sour starter were added loss of phytic acid did not exceed 29%. Supplementing soda in taftoon and naan bread formula significantly lowered phytic acid hydrolysis during fermentation. Soda had no apparent improvement on physical quality of breads but increased the dough water absorption and lengthened the mixing time.     

Dephosphorylation of Phytic Acid in Rice Bran

Incubation time and temperature, moisture content, and pH were examined to determine the conditions necessary for the hydrolysis of phytic acid in rice bran. The extent of hydrolysis increased with increase in moisture content, and autoclaving for 1 hr at 121°C destroyed a significant proportion of the phytic acid at high moisture contents. Maximum hydrolysis of phytic acid occurred by heating at pH 4.5. Incubation of rice bran slurry for 24 hr at 55°C, pH 5.1 reduced the phytic acid level by approximately 80%.     

Inositol phosphate content and trypsin inhibitor activity in ready-to-eat cruciferous sprouts

Four cruciferous seeds (small radish, radish, white mustard and rapeseed) were germinated in order to study the fate of inositol hexaphosphate (IP-6, phytic acid) and activity of trypsin inhibitor (TIA). Reduction in the content of phytic acid depended on the time of germination. After four days of germination, when sprouts were ready-to-eat, the amount of this compound was about 50% lower in three out of the four seeds evaluated. Next, a sharp reduction in phytic acid occurred during thermal treatments (pasteurization and sterilization) of germinated rapeseed and radish sprouts. In thermal processes, a decrease in inositol hexaphosphate content was accompanied by the appearance of lower forms of inositol phosphates: IP-5, IP-4 and IP-3.The analysis of TIA, in rapeseed and radish seeds, in four-day sprouts and in these sprouts after thermal treatment, showed that only thermal processes caused complete disappearance this activity.     

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.