The mechanical property and phase structures of wheat proteins/polyvinyl alcohol blends studied by high-resolution solid-state NMR

Research on the influences of two alcohol soluble glutenins on the retrogradation of wheat amylopectin/amylose

Two alcohol soluble glutenins (ASGLUs) were extracted from gluten and further separated by column chromatography. The ASGLUs with Mw lower than 20,000 (ASGLU 1) and Mw higher than 70,000 (ASGLU 2) show the total amino acid contents of 86.71 g/100 g and 62.847 g/100 g respectively. Both of them are rich in Glu (45.574% and 43.224%) and Pro (15.447% and 16.370%) while poor in cys-s, met and lys (less than 1%). When wheat amylopectin/amylose retrogrades with those ASGLUs, the retrogradation rate of amylopectin with ASGLU 1 enhances significantly. UV-Vis, X-ray diffraction, FT-IR, DSC, CD and solid ¹³C NMR suggest that the double helixes of amylopectin short-chain branching are unwound during gelatinization. The hydrogen bonds of ASGLU 1 between amide and carbonyl oxygen are destroyed, meanwhile, β-sheets are unfolded. During retrogradation, ASGLU 1 with less steric hindrance gets into the crevice of amylopectin and combines with the short-chain branching by hydrogen bond. The retrogradation dynamics show that the nucleation type of amylopectin-ASGLU 1 changes from instantaneous to rod-like growth during the process of retrogradation. β-sheet of ASGLU 1 changes to β-turn and random conformations at the meantime. The results provide a key targeting to control retrogradation of dough.

Simultaneous electronic and ionic conduction in ionic liquid imbibed polyacetylene-like conjugated polymer films

Electron and ion conducting polymer film prepared by hydroiodic acid catalyzed dehydration of poly(vinyl alcohol) and 1-propyl-3-methylimidazolium iodide blend.

Characterization and ornidazole releasein vitro of a novel composite film prepared with chitosan/poly(vinyl alcohol)/alginate

To create a moist environment for rapid wound healing, a new C-P-A film with sustained antibacterial capacity had been developed by the casting/solvent evaporation method. This new type of C-P-A film consists of a chitosan top layer and sodium alginate sublayer separated by an ornidazole-incorporated poly(vinyl alcohol) layer, exhibited perfect binding characteristics among the three layers. Physical characterization of the C-P-A film showed that the triple-layerd film had excellent light transmittance, control of water vapor transmission rate, and fluid drainage ability promotion, compared with the single-layer film. From the in vitro release studies, about 90% of OD was released from the composite films within 60 min, and no significant difference was observed in cumulative release percentage with increases in the drug content. The composite film at low concentration of OD (1.0 mg/cm2) showed effective antimicrobial activity in the cultures of Staphylococcus aureus and Escherichia coli in agar plates. The results obtained in this work indicated that the new type of C-P-A composite film incorporated with ornidazole has the potential for wound dressing application.