Crystal structure of amylose complexes with small ligands

International audienc

Facile Preparation Method for Inclusion Complexes between Amylose and Polytetrahydrofurans

<p>Several methods were used to investigate the possibility of preparing inclusion complexes between amylose and polytetrahydrofurans (PTHF) via direct mixing. Potato amylose (M-v similar to 200 kg/mol) and synthetic amylose (M-n 42 kg/mol) were complexed with PTHF having different molecular weights (Mn between 650 and 2900 g/mol) to study the effect of the length of the host and the guest molecules on the complexation. The resulted products were studied by differential scanning calorimetry (DSC) that showed a characteristic melting peak in the range of 120-140 degrees C. Emulsification of both amylose and polytetrahydrofuran improved the complexation. The largest amount of complexes was obtained with shorter PTHF chains, which also resulted in less amylose retrogradation. Furthermore, PTHF chains with similar molecular weight but different end groups were used. Amine terminated PTHF formed a higher amount of complexes compared to the hydroxyl terminated PTHF. However, no amylose complexes were formed using benzoyl terminated PTHF with low molecular weight. This is due to the bulky group of benzoyl, which indicates that the mechanism of the complexation between amylose and PTHF occurs via insertion rather than wrapping. In addition, X-ray diffraction (XRD) analysis showed that the included PTHFs induced the formation of the so-called V-amylose with six glucose residues per helix turn. Some additional diffraction peaks indicate that the induced V-6-amylose is probably an intermediate or the mixtures between V6I- and V-6II-amylose.</p>

Effect of Synthetic Emulsifier and Natural Biosurfactant on Feed Process and Quality of Pelletized Feed in Broiler Diet

A feed production trial was conducted to study the effect of synthetic emulsifier and natural biosurfactant the process and quality of pelletized broiler feed. A corn-soy based broiler diet was formulated with fixed ratio 2:1 of oil-to-water with two types of emulsifiers, namely glyceryl polyethylene glycol ricinoleate synthetic emulsifier and lysophosphatidylcholine natural biosurfactant. T1: Basal diet with no water and no emulsifier; T2: Basal diet with water and no emulsifier; T3: Basal diet with water and synthetic emulsifier glyceryl polyethylene glycol ricinoleate; T4: Basal diet with water and a natural biosurfactant lysophosphatidylcholine as comparative treatment. The treatment diets were manufactured by a commercial feed mill. The electricity cost and meal temperature were measured during the process of milling. Composite samples were collected from different processed points, tested for physical properties, chemical stability and biostability of pelletized feed. Pellet quality of emulsifier supplemented diets was significantly (p<0.05) improved in crumble and pellet intact form. Correlation between emulsifier and pelletize processed cost was not observed in this present study. No deteriorate effect was observed in hydrolytic rancidity (AV), oxidation rancidity (PV), mold count, moisture content and water activity. However, percentage of starch gelatinization on pelletized feed was significantly (p< 0.0001) improved in both types of emulsifier treated diets. These results demonstrated that the addition of emulsifier to broiler diet improved pellet quality to some extent although significant difference between synthetic emulsifier and natural biosurfactant was not observed