双醛淀粉湿强剂的合成

本文研究了以木薯淀粉为原料，以高碘酸钠为氧化剂合成双醛淀粉（Dialdehyde starch,简称DAS）的工艺条件。通过对不同氧化程度双醛淀粉的红外光谱和结晶度研究，对制备DAS的反应进程进行了探讨。结果表明，根据需要可制和不同氧化程度的DAS，双醛淀粉与原淀粉相比其物理和化学性质都发生了很大的变化。     

双醛淀粉的性质及其提高纸湿强度的效果

由高碘酸钠氧化木薯淀粉所得的双醛淀粉，颗粒保持完整，但随着氧化度的增加，颗粒表面逐渐变得粗糙，说明反应主要发生在颗粒表面。氧化达一定程度时，淀粉的结晶度和偏光十字消失，淀粉颗粒与碘络合颜色也发生变化，应用研究结果表明，双醛淀粉用作湿强剂纸页初始湿强度是原纸的18.01倍，其湿强性能与PAE应用效果相近，而浸渍30min后强度只有PAE的1/3左右。     

双醛淀粉流变性的研究

双醛淀粉毒性低、化学反应活性高,广泛应用于各种工业,是一种很重要的化工原料,而双醛淀粉的流变性会对双醛淀粉的应用产生重大的影响。研究了不同pH下制备双醛淀粉的流变性,结果表明溶液呈胀流型,提高剪切速率,黏度略有增加,pH3.5下制备双醛淀粉的黏度比pH7下制备双醛淀粉的黏度低。     

双醛淀粉上浆剂的制备研究

利用高碘酸钠氧化可溶性淀粉制得双醛淀粉(DAS)，用碱滴定法，测其氧化度(醛基含量)．并研究不同反应时间、初始pH值、温度对产物氧化度的影响，确定最佳反应条件，分别是反应时间1.2h，初始pH值1．4．     

尿素-双醛淀粉浆料的应用

为制备出性质稳定的尿素-双醛淀粉,并确定与原淀粉的最佳配比,分析了合成尿素-双醛淀粉时的影响因素,并对比测试了不同配比的尿素-双醛淀粉与原淀粉浆膜的外观及浆液性能。结果表明尿素-双醛淀粉与原淀粉以一定配比使用时,性能优良,适宜用作浆料对经纱进行上浆。     

用于肉类腐败监测的纳米银混合凝胶的简便制备

为检测肉类腐败产生的H₂S，制备银纳米颗粒混合双醛淀粉-壳聚糖-聚乙烯醇甘油凝胶。以木薯淀粉为原料，通过氧化反应，得到具有强还原基团的双醛淀粉。以壳聚糖和聚乙烯醇为交联剂，以甘油为溶剂，通过交联反应和原位还原反应，得到银纳米颗粒混合双醛淀粉-壳聚糖-聚乙烯醇甘油凝胶。所得银纳米颗粒混合凝胶具有较高的机械强度和形状稳定性，且对于硫化氢有快速高效的响应而出现明显的颜色变化，可用于智能包装材料监测鸡胸肉和猪里脊肉的品质。     

木薯淀粉制备纸张湿强剂的研究

本文利用广西丰富的木薯淀粉为原料,以价格相对比较便宜的高碘酸钠为氧化剂,探索最优化的双醛淀粉合成条件,并对合成的双醛淀粉进行表征分析.     

双醛淀粉制备工艺的优化研究

采用高碘酸盐氧化玉米淀粉的方法制备双醛淀粉,探讨了pH值、高碘酸钠与淀粉摩尔比、高碘酸钠浓度、反应温度、反应时间及投料方式对双醛淀粉中醛基含量的影响,得出双醛淀粉制备工艺的优化条件。结果显示,在pH值为1.2～1.5、高碘酸钠与淀粉的摩尔比为1.1∶1、高碘酸钠浓度为0.5mol/L、反应温度在33～40℃之间、反应时间3h条件下,并采用将淀粉加入到高碘酸钠溶液中的投料方式,可得到高醛基含量的双醛淀粉。     

阳离子淀粉在造纸工业中的应用

造纸工业上应用的淀粉主要为改性淀粉,常用的有：氧化淀粉、阳离子淀粉、阴离子淀粉、磷酸酯淀粉和双醛淀粉等。其中阳离子淀粉因其具有分散性好、保留高、增强效果显著、污染小的优点,在国外很早就已应用于造纸中。     

正交优化制备双醛淀粉研究

双醛淀粉毒性低,化学活性高,广泛用于各种工业,是一种很重要化工原料,但我国对双醛淀粉开发和生产还处于起步阶段。该研究以玉米淀粉为原料,高碘酸钠为氧化剂,采用正交优化法对制备双醛淀粉工艺条件进行研究;最佳工艺条件为:反应温度为35℃,反应时间为3.5小时,高碘酸钠浓度为0.5 mol／L,pH值为4.0,高碘酸钠与淀粉摩尔比为1.1:1。     

Rheological Characteristics and Morphology of Dialdehyde Starch/Meat Composites during Heating

ABSTRACT:  Dialdehyde starch (DAS) was added to pork ham batter. The effects of DAS on the meat protein gel during heating were investigated using thermal and rheological analyses. In this study, the degree of DAS oxidation was controlled by the reaction time. The DSC thermogram showed that increasing the degree of oxidation resulted in DAS having a higher gelatinization temperature and lower heat absorption. In dialdehyde starch/meat (DAS/M) composites, meat protein reduced the availability of water to starch and raised the gelatinization temperature and heat absorbed by the composites. The G '_max of the composites was greater than the linear combination of their components. The rheological properties of DAS were a major factor affecting the properties of its composites. Scanning electron microscopy and light microscopy with the aid of histologic technique revealed the network and distribution of DAS and DAS/M composites. The protein matrix formed the backbone of the network and gelatinized starch was trapped in the protein structure.     

采用低温工艺制备双醛淀粉

双醛淀粉的制备大多是在 3 0～ 40℃下 ,非均相体系中完成。文中采用拟均相体系在低温下 ( 0℃ )制备了双醛淀粉。试验结果表明 ,拟均相体系使低温下淀粉被氧化的速度提高 ;而且避免了DAS被过氧化的可能 ,产品性能得到改善 ;使反应的最适 pH由原来的 1 5提高到 4 4。     

双醛淀粉改性明胶膜的制备与性能研究

利用双醛淀粉(DAS)交联明胶,制备了DAS改性明胶膜,研究了DAS改性对明胶膜力学性能、溶胀性能、吸湿性能和热降解稳定性能的影响。结果表明:DAS能有效地与明胶发生交联反应。适量DAS的交联可大幅提高明胶膜的拉伸强度。DAS交联可赋予明胶稳定的结构,有效地降低明胶膜对水的敏感性。随着DAS用量的增加,明胶膜的平衡溶胀率逐渐降低。DAS交联可降低明胶膜的吸湿率,在DAS用量为3%～5%时,膜的平衡吸湿率最低。经DAS改性后,明胶膜的热降解温度升高,表明其耐热降解稳定性得到提高。     

拟均相两段工艺氧化法制备双醛淀粉

以绿豆淀粉为原料,NaIO4为氧化剂的拟均相两段工艺制备双醛淀粉(dialdehyde starch,DAS),考察预处理阶段中温度、酶处理、超声活化和氧化阶段中反应温度、反应时间、pH值、投料比、NaIO4浓度、淀粉乳浓度、相转移催化剂对制备双醛淀粉的影响,前段的预处理采用超声活化处理,后段的氧化工艺考察相转移催化剂的影响,并用正交法对制备双醛淀粉的工艺进行优化。结果表明：在以醛基含量为考察指标,预处理时不宜用酶,处理温度50～60℃,经30℃、40W、40kHz超声活化淀粉乳30min能有效提高淀粉与NaIO4的氧化反应活性,制得高醛基含量的DAS。相转移催化剂对提高产品醛基含量有一定作用。经正交试验优化得到的最佳条件为：以十六烷基三甲基氯化铵为相转移催化剂、反应时间2h、反应温度40℃、n(NaIO4):n(淀粉)=1.0:1.0、NaIO4浓度0.5mol/L、淀粉乳质量分数10%、体系pH2,在此条件下,制得的DAS双醛含量为96.81%。经光谱和理化性能等指标的检测证实所得的DAS与文献报道的DAS相符合。     

The effect of cooking on the antibacterial activity of the dialdehyde starch suspensions

Dialdehyde starch (DAS) has been found to show a significant antibacterial activity after cooking. A study of the antibacterial efficiency of the DAS suspensions was performed on a Gram‐negative bacterium Escherichia coli and a Gram‐positive bacterium Staphylococcus aureus. After heating at 90–95°C in deionized water for 2 h, the as‐prepared DAS aqueous suspension (DAS‐AS) demonstrated strong antibacterial activity against the test bacteria, whereas the DAS granular suspension showed very limited antibacterial activity. The antibacterial activity of the DAS suspension is mainly attributed to the reactivity of its dialdehyde functional groups, which is related to the dispersion and the pH values of the test media. The physicochemical changes of DAS‐AS were determined by particle size, dispersibility, gel permeation chromatography (GPC), Fourier transform infrared spectroscopy (FTIR), and UV–Vis measurements. Upon heating, the dispersibility of DAS in deionized water significantly increased. Meanwhile, the granules of DAS were disintegrated with significantly decreasing the DAS particle size. The soluble parts of DAS‐AS and the as‐received DAS (DAS‐R) had similar molecular weight distribution as determined by GPC analysis. DAS‐AS had more soluble materials in GPC medium (DMSO) than DAS‐R, suggesting that DAS‐AS and DAS‐R were different. Chemical changes of DAS during cooking such as the formation of the conjugated aldehyde and carboxylic acid functions were observed by the FTIR and UV–Vis spectroscopic analysis.     

淀粉醛强化大豆分离蛋白/槲皮素复合膜制备及性能研究

目的 探究淀粉醛(dialdehyde starch,DAS)对大豆分离蛋白(soy protein isolate,SPI)/槲皮素(quercetin,QR)复合膜特性的影响。方法 以青稞淀粉为原料,通过高碘酸钠氧化制备了DAS,以SPI为基质,以DAS和QR为添加物,以拉伸强度、水分阻隔性能、抗氧化性能为指标进行单因素试验,通过响应面优化试验筛选出DAS强化的SPI/QR复合膜最佳制备条件后,对复合膜的微观结构进行表征,并对其物理学性能进行测试。结果 DAS强化的SPI/QR复合膜最佳制备条件为每100 mL蒸馏水中添加SPI 6.00 g、pH为8、DAS 5%、QR 4%、DES 25%(DAS、QR、DES以SPI质量计)。在此条件下,薄膜的拉伸强度为(7.37±0.39) MPa、水蒸气透过系数为(3.54±0.29)×10^-11 g/(m·s·Pa)、抗氧化活性为(70.88±0.40)%。结构表征结果表明, DAS的添加使得该复合膜分子间形成了共价亚胺键,表面结构及横断面结构更加致密。此外,该复合膜具有较好的热稳定性、紫外阻隔性、疏水性。结论 D...     

Non-structural carbohydrate partitioning in Phaseolus vulgaris after vegetative growth

This study provides information on the concentration and quantity of starch, reducing sugars, total sugars, and non-reducing oligosaccharides in the organs of the common bean plant (Phaseolus vulgarisL cv Jamapa) during growth. The following observations were made: (1) the root, stems and branches were temporary carbohydrate storage organs; (2) until 80 days after sowing (DAS), the leaves were the major contributors to the non-structural carbohydrates of the whole plant; (3) during the developmental period studied, non-structural carbohydrate content in the rachis and pulvinus changed frequently; (4) the pod walls contained between 5 and 8% of total sugars at 72 DAS and by maturity soluble sugars diminished to less than 1%; (5) during seed growth (until 80 DAS), the pod walls contained between 11 and 18% starch (dry weight basis) and by maturity this carbohydrate had decreased to 2% of dry weight; and (6) starch represented the major non-structural storage carbohydrate in mature seeds (29%), as opposed to soluble sugars, which amounted to 2·3% of the dry weight.     

西米醋酸酯淀粉物化性质研究

利用扫描电子显微镜、聚焦光束反射测量仪,红外光谱仪和布拉班德粘度计对西米醋酸酯淀粉性质进行测定和分析,并与马铃薯醋酸酯淀粉进行比较。结果表明:马铃薯淀粉较西米淀粉更易引入乙酰基,乙酰化后淀粉颗粒形状未发生大的改变,西米原淀粉粒度分布为单峰,而马铃薯原淀粉粒度分布为双峰,前者平均粒径大于后者,乙酰化后西米淀粉和马铃薯淀粉粒径均增大;经醋酸酐酯化后西米淀粉和马铃薯淀粉起糊温度、峰值温度及峰值粘度均降低,热稳定性增加,凝沉性变弱。