大豆苷元磷酰化改性及条件优化研究

通过Atherton–Todd反应合成7种不同链长磷酰化大豆苷元衍生物,产物分别用1HNMR、13C NMR、IR、MS等分析手段进行表征;结果表明,在大豆苷元7–位羟基上发生反应,生成7种磷酰化大豆苷元单酯。考察各种影响因素对大豆苷元磷酰化影响,确定其最佳工艺条件:物料比n(大豆苷元)∶n(亚磷酸二烷基酯)为1∶3、反应时间15 h、催化剂(三乙胺)用量0.8 ml、反应温度30℃时,最高产率达到78%;同时实验表明,磷酰化试剂碳链长短对反应产率没有明显影响。     

食品用交联淀粉的研究（下）

结果与分析一、甘薯淀粉的交联正交实验结果见表2。实验结果进行数据处理,结果表明,反应时间和温度、硫酸钠和三氯氧磷用量对产品的热糊粘度稳定性都有显著影响(显著水平0.05);较理想的制备条件为反应时间60分钟,反应温度45℃,硫酸钠用量15.0%,三氯氧磷用量0.075%.     

响应面法优化瓜尔胶交联工艺参数

为了改善瓜尔胶性能,拓宽其应用范围,对瓜尔胶进行交联改性。以瓜尔胶为原料、三氯氧磷为交联剂、 氢氧化钠为催化剂、乙醇为溶剂,对交联瓜尔胶的制备工艺进行了研究。考察反应温度、反应时间、三氯氧磷用量 和pH值对交联瓜尔胶沉降积的影响。在单因素试验基础上,利用响应面法优化瓜尔胶交联工艺参数。结果表明, 影响瓜尔胶交联主次顺序依次为：三氯氧磷用量、反应时间、反应温度、pH值。制备交联瓜尔胶的最佳工艺条件 为反应时间75 min、反应温度33 ℃、三氯氧磷用量1.2%、pH 11.5,此条件下沉降积为1.03 mL。     

果胶的磷酸化修饰及其免疫活性研究

以溶剂、反应时间、反应温度、三氯氧磷与果胶液固比为考察因素,磷含量为指标,研究果胶的磷酸化合成工艺,并对磷酸化修饰前后的果胶进行T淋巴细胞免疫增殖实验。结果表明:极性大的偶极溶剂和较高的反应温度有利于提高磷含量;随着溶剂用量、反应时间以及三氯氧磷用量的增加,磷含量先增加后下降。在反应温度50℃、反应时间3.0 h、三氯氧磷与果胶的液固比为3∶1的最佳合成工艺条件下,磷酸化果胶中的磷含量可高达11.52%。免疫增殖实验结果表明:苹果果胶、低磷含量和高磷含量的磷酸化苹果果胶没有免疫活性,中等磷含量的磷酸化苹果果胶有明显的免疫抑制活性。     

三氯氧磷交联木薯淀粉颗粒膨胀历程及溶胀机理研究

利用木薯淀粉与三氯氧磷的交联反应,通过控制交联反应程度,成功地控制了交联淀粉颗粒的膨胀并使其停留在不同的溶胀阶段,详细地研究了处在不同溶胀阶段的三氯氧磷交联木薯淀粉颗粒的结构特征和变化趋势,揭示了三氯氧磷交联木薯淀粉颗粒的具体的膨胀历程及溶胀机理,即木薯淀粉是“花蕾绽放式”膨胀历程。     

新型活性磷酸酯皮革加脂剂的研究

本文研究了天然油脂改性产物的磷酰化反应,并用高碳醇对其磷酰化产物进行接枝扩链.制成一种新型的活性皮革加脂剂.同时进一步探讨了该活性加脂剂的应用特性.     

大豆分离蛋白的磷酸化改性

采用三氯氧磷对大豆分离蛋白进行磷酸化改性，磷酸化条件为：大豆分离蛋白浓度为4％，。反应pH值为10—1l，加入三氯氧磷与大豆分离蛋白物质的量比为1：3000。测定了改性前后，大豆分离蛋白的水溶性，水溶液的粘度，以及凝胶性，发现大豆分离蛋白的功能特性有了很大的改善。改性后大豆分离蛋白的等电点由4．5漂移到了3．0左右。用^31P核磁共振谱，证实了三氯氧磷与大豆分离蛋白反应的实质主要是赖氨酸及精氨酸残基进行氨基磷酯化反应。     

非天然磷酰化氨基酸对胰蛋白酶的荧光猝灭效应

作者利用荧光法研究了非天然L-型氨基酸磷酰化前后与胰蛋白酶的相互作用。实验结果表明,L-2-氨基戊酸、庚酸、辛酸及壬酸非天然氨基酸不能使胰蛋白酶的荧光强度减弱,非天然氨基酸磷酰化后能够对胰蛋白酶产生荧光猝灭。同时,浓度不同、侧链长度不同的同系列磷酰化氨基酸对胰蛋白酶的猝灭效应均不同。随着非天然脂肪酸链磷酰化氨基酸侧链的增长及磷酰化庚酸浓度的增大,胰蛋白酶的荧光强度均明显降低,并且其荧光可以被完全猝灭。非天然氨基酸的磷酰化能够影响非天然氨基酸与胰蛋白酶的相互作用。     

酯化交联淀粉反应及性质的研究

由三氯氧磷变性木薯淀粉所得的酯化交联淀粉,颗粒完整,形貌和偏光十字形态保持不变,反应主要发生在淀粉颗粒的无定形区内;经红外光谱等检测,发现产物分子中存在P—O—C和P＝O基团,表明淀粉分子中的羟基置换出三氯氧磷分子中的氯原子而发生酯化和交联;极小取代度的变性淀粉,其碘复合物的可见光吸收光谱与原淀粉相似,三氯氧磷最先和支淀粉作用.     

含磷-氮有机硼阻燃剂的合成与应用

以硼酸、二乙醇胺为原料,甲苯为带水剂,合成二乙醇胺硼酸酯(Ⅰ);以三氯氧磷和乙二醇为原料,合成二乙二醇基磷酰氯(Ⅱ);(Ⅰ)与(Ⅱ)进一步反应,生成含磷、氮有机硼阻燃剂(Ⅲ).反应条件为:n(Ⅰ)∶n(Ⅱ)=1∶1,100℃反应2 h,收率达74%;3步总收率达60%.探讨了阻燃剂质量浓度、焙烘温度、焙烘时间等因素对棉织物阻燃效果的影响.结果表明:阻燃剂质量浓度为300 g/L、焙烘温度为160℃、焙烘时间为60 s时,整理后织物的阻燃效果显著,达到B1级.     

有机磷农药多残留检测化学发光标记物的 合成及鉴定

目的 以O,O-二乙基硫代磷酰氯和鲁米诺为原料, 合成一种新型的化学发光标记物, 用于后续的二乙氧基类有机磷农药多残留化学发光免疫法检测。方法 取鲁米诺和O,O-二乙基硫代磷酰氯溶于二氯甲烷中, 以三乙胺作为缚酸剂, 冰浴下反应8 h后分出有机层, 产物经柱层析纯化, 即得到化学发光标记物。结果 产物经紫外、红外鉴定, 实验结果表明反应产物即为所需的化学发光标记物, 产物在BPCL上进行发光特性测定, 表现出较强的发光能力, 最大发光强度达到9000 mV。结论 本方法合成的化学发光标记物具有较强的发光能力, 能用于后续的二乙氧基类有机磷农药多残留的化学发光免疫检测。     

Formulation Protocol and Dicationic Salts Affect Protein Functionality of Model System Beef Batters

ABSTRACT: The objective of this study was to determine if addition, and order of addition, of CaCl₂ and MgCl₂ affected protein functionality of lean beef preblends. Four treatments were applied to non-preblended (NPB) batters prior to thermal processing. Six treatments were applied to preblended (PB) batters 12 h prior to thermal processing. All treatments contained 2% NaCl. Dicationic salts decreased raw pH in NPB and PB batters, while cooked pH was unaffected. Magnesium chloride in NPB and CaCl₂+ MgCl₂ in PB batters resulted in the highest total soluble protein (TSP). Calcium chloride + MgCl₂ in NPB batters resulted in firmer gels compared to the control. Magnesium chloride, in both NPB and PB, caused the greatest increase in soluble myosin, and preblending decreased myosin solubility.     

Effect of ascorbic acid on bone marrow-derived mesenchymal stem cell proliferation and differentiation

Mesenchymal stem cells (MSCs) derived from bone marrow are an important tool in tissue engineering and cell-based therapies because of their multipotent capacity. Majority of studies on MSCs have investigated the roles of growth factors, cytokines, and hormones. Antioxidants such as ascorbic acid can be used to expand MSCs while preserving their differentiation ability. Moreover, ascorbic acid can also stimulate MSC proliferation without reciprocal loss of phenotype and differentiation potency. In this study, we evaluated the effects of ascorbic acid on the proliferation, differentiation, extracellular matrix (ECM) secretion of MSCs. The MSCs were cultured in media containing various concentrations (0-500 microM) of L-ascorbate-2-phosphate (Asc-2-P) for 2 weeks, following which they were differentiated into adipocytes and osteoblasts. Ascorbic acid stimulated ECM secretion (collagen and glycosaminoglycan) and cell proliferation. Moreover, the phenotypes of the experimental groups as well as the differentiation potential of MSCs remained unchanged. The apparent absence of decreased cell density or morphologic change is consistent with the toxicity observed with 5-250 microM concentrations of Asc-2-P. The results demonstrate that MSC proliferation or differentiation depends on ascorbic acid concentration.     

Influence of Various Salts and Water Soluble Compounds on the Water and Fat Exudation and Gel Strength of Meat Batters

Meat batters were prepared in which the sodium or chloride from salt was replaced by other ions. Then the functional properties of the batters were determined by measuring water and fat exudation, and gel strength. Generally cations from groups IA and IIA of the periodic table equalled or surpassed the batters made with sodium only, whereas other cations decreased water binding. Of the anions, bromide, orthoand pyrophosphates, and citrate increased water retention. Zinc chloride increased fat exudation greatly. Magnesium chloride and sodium pyrophosphate increased the gel strength. Magnesium and calcium chlorides made good batters although they caused a drop of approximately 0.25 pH units. Sodium thiosulfate, sodium borohydride, starch, sucrose, glycerol, arginine and urea improved the water binding and gel strength, while nonionic detergents, monoglycerides and alcohols were very detrimental.     

DTB结晶器在晶体氯化镁生产中的应用分析

在以提溴母液为原料的氯化镁生产中,硫酸镁及氯化钠等杂质直接影响产品质量,经过试验利用DTB结晶器生产晶体氯化镁可以有效降低产品杂质含量,产品中六水氯化镁含纯99%以上,达到食品添加剂标准,提高了产品档次,增加了企业效益。     

Degradation of natural phosphorylated compounds and added polyphosphates in milk by Pseudomonas fluorescens CECT378, Lactococcus lactis CECT539, and Kluyveromyces marxianus CECT10584

The degradation of natural phosphorylated compounds (galactose-1-phosphate, N-acetyl-glucosamine-1-phosphate, glycerophosphoethanolamine, and glycerophosphocholine) and added phosphorylated compounds (diphosphate) in milk was investigated by phosphorus 31 nuclear magnetic resonance on the incubation of a sterile milk with Pseudomonas fluorescens CECT381, Lactococcus lactis CECT539, and Kluyveromyces marxianus CECT10584. This preliminary study showed that the degradation of these compounds was dependent on the compound, microorganism, and temperature of incubation. K. marxianus CECT10584 did not show any capability to degrade these compounds, and L. lactis CECT539 was only able to degrade diphosphate at its optimum growth temperature. P. fluorescens CECT381 was the most active strain and possessed more hydrolytic capabilities at 10 degrees C than at its optimum growth temperature. It is suggested that cold-induced enzymes are involved in the ability of P. fluorescens CECT381 to hydrolyze the natural phosphorylated compounds in milk. Consequent potential alterations of dairy products are discussed.     

氧化镁铵盐法制备高纯过氧化镁

在氯化铵溶液体系中,以氧化镁,过氧化氢为原料,制备高纯过氧化镁。研究表明采用氧化镁活性大于100,氯化铵/氧化镁不小于10%,过氧化氢∶氧化镁不小于4∶1,反应温度大于40℃情况下,反应时间不小于30 min,可制备出纯度大于90%的过氧化镁。     

溶剂介质法制备碱式氯化镁晶须的工艺研究

以氯化镁为原料,研究了溶剂介质法制备碱式氯化镁晶须的影响因素.详细考察了有机溶剂的种类、陈化时间和搅拌速度对氯化镁晶须复合材料制备的影响.根据SEM的测试图片结果显示,提出了制备氯化镁晶须复合材料的最佳工艺条件是：以乙醇为溶剂介质,搅拌速度120 r/min,陈化时间24h.     

脂肪酸阳离子甘油酯CMESA的合成研究

季铵盐型阳离子表面活性剂是一种用途广泛的化工产品,本研究以自制季铵盐型活性醚化剂环氧氯丙基三甲基氯化铵(GTMAC)改性十八酸合成阳离子单酯2-羟基-N,N,N-三甲基-3-硬脂酰氧基丙基氯化铵(CMESA)。实验得出CMESA的最佳合成条件为:超声频率40 kHz,n(GTMAC)∶n(十八酸)=1.5∶1.0,反应时间2.5 h,pH=6,反应温度40℃,CMESA产率93.47%。通过元素分析和和红外光谱对产品结构进行了表征。     

纸张用含氟防油剂的合成和应用研究

合成了N-羟乙基全氟辛基磺酰胺及全氟烷基磷酸酯,对合成条件进行了讨论,通过红外以及核磁1HNMR与19FNMR确定了化合物的化学结构,并将其应用于纸张的防油整理.将其与聚乙烯醇与氧化淀粉一起应用于纸张的防油,根据国际通用测试法Oil Kit Test-TAPPI 557测试,其防油级别可以达到11级.对其防油机理也进行了探讨.