Controlled release of diclofenac from matrix polymer of chitosan and oxidized konjac glucomannan

The controlled release of diclofenac sodium (DFNa) from a chitosan-oxidized konjac glucomannan (CTS-OKG) polymer film was studied. Konjac glucomannan (KGM) was initially oxidized by sodium periodate and then cross-linked to CTS via imine bonds (-C=N-) to form the new CTS-OKG copolymer. The DFNa loaded CTS-OKG polymers were characterized by Fourier transformed infrared spectroscopy (FT-IR) and X-ray diffractometry (XRD). Finally, the release profiles of DFNa from the CTS-OKG polymer matrices were evaluated in a simulated gastrointestinal fluid system comprised of two hours in simulated gastric fluid (SGF; pH 1.2) followed by 24 h in simulated intestinal fluid (SIF; pH 7.4). A 1:2:1 (w/w/w) ratio of CTS:OKG:DFNa prepared at room temperature for 3 hours gave the highest % encapsulation efficiency (EE) of 95.6 ± 0.6 and resulted in a minimal release of DFNa (<1% over 2 h) in SGF (pH 1.2) and a significantly improved sustained release in SIF (pH 7.4) with ~6% and 19% release over 8 and 24 h, respectively), some 15- and five-fold lower than that of the two commercial DFNa preparations, Diclosian and Voltaren. This formulation may be used for further study as a long term intestine controlled release drug model (at least 3 days).     

魔芋多糖在茶饮料中的稳定作用机理研究

研究了魔芋多糖稳定茶饮料的作用机理。经乙醇沉淀、透射和扫描电镜观察表明,魔芋多糖与茶汤成分及粒子之间发生了强烈的吸附作用,并形成水溶性复合体均匀分散于茶汤溶液中。X-射线衍射和DSC差示扫描量热法分析显示,KGM、茶汤固形物以及魔芋茶饮料的固形物均属无定形粉末。实验还表明,魔芋多糖在茶汤中的分子量均小于水溶液中的分子量,在水溶液中为4.83378×10⁵,红茶汤中为3.41182×10⁵,乌龙茶汤中为3.51307×10⁵。魔芋茶汤具有较强的耐电解质聚沉能力。     

亲水胶体和玉米变性淀粉对低脂鸡肉肠的影响

将卡拉胶、魔芋胶和玉米变性淀粉添加到低脂鸡肉肠中,按三因素三水平的正交试验表添加,研究其对鸡肉肠汁液损失(TEF)、产率、硬度和弹性的影响。结果表明:卡拉胶对鸡肉肠TEF影响极显著(P<0.01),对鸡肉肠硬度和弹性有显著影响(P<0.05);魔芋胶对鸡肉肠产率和硬度影响极显著(P<0.01),对鸡肉肠弹性影响显著(P<0.05);玉米变性淀粉对鸡肉肠TEF、硬度和弹性影响极显著(P<0.01),对产率影响显著(P<0.05)。感官评定结果与鸡肉肠的TEF呈极显著性正相关(P<0.01,r=0.692)。结合感官评定结果和鸡肉肠TEF结果,得出低脂鸡肉肠的优化结果:添加卡拉胶0.5%、魔芋胶0.5%、玉米变性淀粉12%。     

羧甲基魔芋葡甘聚糖/壳聚糖凝胶化性能研究

羧甲基魔芋葡甘聚糖 /壳聚糖通过改变共混比例制备了混合凝胶 ,当多糖总质量分数为 4 %、盐离子浓度为 1 .6mol·L-1时 ,羧甲基魔芋葡甘聚糖对壳聚糖的共混质量比为 2 0 /80 ,在 70℃共混并恒温 30min ,可达凝胶强度最大值 ;研究了制备温度、恒温时间、体系中盐离子浓度及壳聚糖粘均分子质量与脱乙酰度对凝胶化影响。同时从FT IR谱图上分析了这两种多糖凝胶化作用机理     

锆交联葡甘聚糖凝胶球的制备及吸附性能

利用锆氧离子交联羧甲基葡甘聚糖制得了新型交联羧甲基葡甘聚糖-锆(CMKGM-Zr)凝胶球,通过扫描电镜对凝胶球的结构进行了表征,利用红外光谱分析吸附反应前后凝胶球的变化。研究了凝胶球对苯甲酸的吸附性能,分别考察了吸附时间、pH值对吸附的影响,进而根据凝胶球对苯甲酸的吸附等温线,计算了吸附过程的热力学参数,对实验数据进行了拟合。结果表明,以质量分数为2.0%的羧甲基葡甘聚糖和2.0%的锆氧离子溶液制备的凝胶球为白色几何形状不规则的空心球,凝胶球机械强度为15.3 g,吸附苯甲酸后ZrO2+与苯甲酸的—COO-发生了反应。在298 K下,pH值为4.5的初始质量浓度为200 mg/L的苯甲酸溶液中CMKGM-Zr对苯甲酸的吸附反应在4 h时达平衡,吸附量最高达79.964 2 mg/g。Freundlich方程适用于所研究的吸附体系,吸附驱动力是焓变和熵变。     

不同土壤硒浓度对花魔芋生长发育及硒含量的影响

研究了不同土壤硒浓度对魔芋生长发育、产量、品质以及球茎硒含量的影响,以期筛选出适合花魔芋生长的最佳土壤硒浓度,为魔芋富硒栽培提供理论依据。结果表明,当土壤硒含量为10.3 mg/kg时,魔芋球茎全粉和精粉中的含硒量分别为0.284和0.187 mg/kg,且对魔芋生长发育、产量形成以及品质无影响。随着土壤中硒浓度增大,球茎硒含量也在不断升高,而对魔芋叶、根系的生长产生了明显的抑制,导致球茎膨大系数减小,葡甘聚糖含量降低。因此,在土壤硒含量不超过10.3 mg/kg区域可栽植魔芋,且魔芋具有一定的富硒能力。     

魔芋葡甘聚糖涂膜对牛角椒货架品质的影响

研究魔芋葡甘聚糖涂膜处理对采后牛角椒果实货架品质的影响。以牛角椒为材料,室温条件下(20±3)℃,分别用3、6、9 g/L魔芋葡甘聚糖涂膜处理果实,以不作任何处理和仅用φ=0.1%次氯酸钠洗果为对照组,比较处理果实和对照果实的质量损失率、商品率、果皮亮度、色泽、色饱和度和叶绿素含量以及过氧化物酶(POD)活性和多酚氧化酶(PPO)活性的变化。结果表明,魔芋葡甘聚糖涂膜减缓了牛角椒果实质量损失率的升高和商品率的降低,保持果皮颜色,提高叶绿素的含量,同时POD活性和 PPO活性的升高。魔芋葡甘聚糖涂膜可有效延缓采后牛角椒果实的成熟衰老进程,对保持牛角椒果实较好的货架品质和商品性有积极作用。     

可降解魔芋葡甘聚糖基互穿膜的制备、结构与性能

魔芋葡甘聚糖(konjac glucomannan, KGM)和聚乙烯醇(poly(vinyl alcohol), PVA)以戊二醛进行交联，成功制备了一种新的互穿聚合物网络(interpenetrating polymer networks, IPN)。以传统的流延法于室温下干燥2 d，得40 μm厚透明IPN膜。以傅立叶红外光谱、扫描电镜、示差扫描量热法、X-射线衍射和紫外可见光谱等表征了膜的结构。结果表明：由于交联键的产生，PVA和KGM分子间发生了强烈的相互作用，当反应时间达到4 h时，分子间达到了完全混溶。拉伸强度、断裂伸长率大大高于而吸湿性显著低于纯PVA膜、KGM膜以及它们的简单共混膜，亦即IPN结构的产生赋予了膜优异的性能。     

Improved physicochemical and structural properties of wheat gluten with konjac glucomannan

Konjac glucomannan (KGM), a dietary fiber, can be used to improve the quality of flour products. In this study, the effects of KGM at different concentrations on the water distribution, morphological, textural, thermal, and structural properties of wheat gluten were studied. KGM improved the physicochemical and structural properties of wheat gluten by changing the water holding capacity, secondary structure, and free sulfhydryl and disulfide bond contents. Scanning electron microscopy confirmed that KGM can evenly fill the network structure, affecting gluten network development. KGM exhibited no effect on moisture content; however, KGM decreased water mobility in wheat gluten. The increased thermal denaturation temperature indicates that KGM can improve the thermal stability of wheat gluten. Sharp changes in texture profile analysis (TPA) parameters were observed around 5% KGM, and elasticity and cohesiveness were optimal after the addition of 4% KGM. In addition, the secondary structure analysis indicated that α-helix and β-sheet structures increased. The addition of 5% KGM increased the content of disulfide bonds by 2.57-fold. Overall, the changes in gluten structure and properties suggest that wheat gluten could be improved the stability, functionality and water holding capacity of gluten by adding KGM.     

魔芋葡甘聚糖涂膜处理对麻竹笋采后贮藏效果的研究

研究了浓度分别为0.4%和0.6%的魔芋葡甘聚糖液态保鲜膜处理对5℃低温条件下贮藏的麻竹笋的保鲜效果。试验结果表明,经过魔芋葡甘聚糖保鲜膜涂膜处理的麻竹笋生理代谢活性缓慢,呼吸速率得到有效的抑制,水分散失量小,蛋白质、还原糖含量分解速率降低,营养成分得到了有效的维持,苯丙氨酸解氨酶(PAL)、过氧化物酶(POD)活性贮藏保鲜期内变化幅度小,纤维素、木质素含量的增加量小,老化进程显著低于对照。其中以0.6%魔芋葡甘聚糖保鲜膜保鲜效果最佳。