The effect of steam explosion pretreatment on biodegradation of lignin in wheat straw was studied in this paper. Through experiments and analysis, 0.8 MPa operation pressure and 1:20 wheat straw to water ratio are optimum for destroying lignin and the maximum of lignin loss rate is 19.94%. After steam explosion pretreatment, the wheat straw was retted by Trametes versicolor for 40 days. Biodegradation rate of lignin was tested and the maximum of 55.40% lignin loss rate was found on day 30. During the whole process of both steam explosion pretreatment and biodegradation, 75.34% lignin was degraded, without steam explosion the biodegradation of raw material the degradation rate of lignin was 31.23% only. FT-IR spectroscopy, TGA and SEM were used for further validating the results of biodegradation.

Crosslinked anionic starch microspheres were prepared with sodium trimetaphosphate (STMP) as crosslinking agent through 5 h w/o emulsification-crosslinking reaction at 50C. Laser diffraction technique and scanning electron microscopy revealed that microspheres had narrow size distribution, good sphericity and fine dispersibility. In addition, drug loading and releasing properties were investigated with Methylene Blue as a model drug on the basis of single-factor study. It was found that the loading ratio of MB was significantly influenced by loading time, dissolution medium, loading temperature as well as MB concentration (P<0.05). Either the increase of loading time or drug concentration could lead to the increase of drug loading amount of microspheres, however, drug loading amount reached its maximum in NaCl (0.9%) dissolution medium at room temperature. Furthermore, the release profile contained two main expulsion processes: an initial burst release followed by a sustained swelling-controlled release.

The effects of starch concentration on the rheological properties of dilute aqueous solutions of cassava starch were investigated. Cassava starch suspensions at different starch concentrations (0.2, 0.4, 0.6, 0.8, and 1.0 wt. %) were heated at 90℃ for 1 h and then rapidly cooled to 25℃. The apparent viscosities of starch solutions were measured as a function of starch concentration. The cassava starch solution with a concentration of 0.2% showed Newtonian behavior, and as the concentration was increased beyond 0.4%, the solutions showed shear-thinning behavior. The flow behavior (apparent viscosity against shear rate) of the solutions was well described using a power law model. The consistency indices increased and the flow behavior indices decreased with the increasing of starch concentration. After storing the solutions at 25℃ for 24 h, precipitation of starch took place instead of gelation. The volume of precipitation bed increased linearly with starch concentration

High-pressure homogenization induced thinning of potato and cassava starch paste was investigated. The starch slurries at a concentration of 2.0 wt.% were heated at 90℃ for 1 h and then rapidly cooled in tap water. The cooled starch pastes were homogenized at various pressures ranging from 0 to 100 MPa using a lab-scale high-pressure homogenizer. The influence of homogenizing pressure on the temperature, apparent viscosity, electrical conductivity, and percent light transmittance of homogenized starch pastes were determined. Temperatures of homogenized starch pastes increased linearly with the increase of the applied pressure, and the rate was 0.177C/MPa and 0.186C/MPa for potato and cassava starch pastes, respectively. After high-pressure homogenization, the apparent viscosities of the starch pastes decreased, while the percent light transmittances of them increased. However, the electrical conductivities of starch pastes were not affected by homogenization.

The dynamic mechanical properties of prepared maize and potato starch films were evaluated for mixtures containing 0%, 10% and 15% (w/w) of sucrose at temperatures ranging from 40.0 to 140.0℃. The spectra of storage modulus (G0), loss modulus (G00), and loss factor (tand) of starch films were acquired. Remarkable reduction in the glass transition temperature of maize and potato starch films was observed with the increasing sucrose content. The spectra of storage modulus (G0), loss modulus (G00), and loss factor (tand) were measured for the second and third time after two and seven days, respectively. The peaks of loss factor (tand) appeared at 59.81±1.86℃ and 95.96±1.67℃ after two-day-storage, but only one peak appeared at 85.46±5.50℃ after seven days. A shifting trend from higher to lower temperature for loss factor was observed after seven days.