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Dong H.,Harbin Engineering University | Yang X.,Harbin Engineering University | Tang J.,Harbin Engineering University | Lu Y.,Harbin Engineering University | Yue G.,China Oil and Foodstuffs Corporation
Harbin Gongcheng Daxue Xuebao/Journal of Harbin Engineering University

A thermoelectric probe was used to measure the one-dimensional and two-dimensional ultrasound intensity distribution of an ultrasound horn in homogeneous water systems. This allowed the mechanism of the ultrasound enhanced chemical process to be obtained. The intensity attenuated as the distance increased in the axial and radial directions, which was in accordance with the standard attenuation function. As the reflection of a flask wall, standing waves were formed at the axial and radial directions. The effects of ultrasound frequency and ultrasound electric power on ultrasound intensity distribution were investigated by constructing two-dimensional ultrasound intensity distribution images. A bubble cloud was formed around the horn tip. The results indicate that the intensity at 40 kHz is higher than at 30 kHz. While under the same frequency, the influence of electric power on ultrasound intensity is slight because of the shielding of the bubble cloud. Source

Wen P.,Gansu Agricultural University | Wen P.,China Agricultural University | Guo H.,China Agricultural University | Zhang H.,China Agricultural University | And 4 more authors.
Protein Journal

The objective of this research was to investigate the influence of glucose on bovine lactoferrin's (LF) conformation, thermodynamic stability and osteoblastic cell proliferation. The conformation and thermodynamic stability of LF was detected by spectroscopic and differential scanning calorimetry (DSC). The osteoblastic cell proliferation of LF at physiological concentrations (100 μg/ml) was measured by BrdU incorporation. The binding constant between glucose and LF is KSV = 5 × 10 -3, and Tyr residues of LF were located in a more hydrophobic environment, while Trp residues were located in a more hydrophilic environment. LF with glucose had increased α-helix and β-sheet contents by 6 and 14 %, respectively. It showed a two-step denaturation of LF. There was a gradual changs in the denaturation temperature and the calorimetric enthalpies (δHcal) with a growing concentration of glucose. It has also revealed that glucose dose dependently reduced the ability of LF to increase MC 3T3-E1 cell proliferation. Increasing the binding with glucose, LF might cause to change its native state, which reduced the stimulation activity of osteoblasts cell proliferation. © Springer Science+Business Media, LLC 2012. Source

Ma X.,Beijing University of Chemical Technology | Yue G.,Beijing University of Chemical Technology | Yue G.,China Oil and Foodstuffs Corporation | Yu J.,Beijing University of Chemical Technology | And 2 more authors.
Journal of Biobased Materials and Bioenergy

Production of concentrated fermentable sugars from cassava bagasse was investigated. The biomass at a solid loading of 10% (wv -1) was pretreated with 1% (ww -1) H 2SO 4 at 120 °C, within varied residence time (30, 60, and 90 min). The conversions of cellulose from pretreated cassava bagasse evaluated by enzymatic saccharificationywere about{80%, which were substantially higher than that of untreated bagasse (62%). Considering cellulose conversion and energy consumption, 30 min was the suitable residence time for acid pretreatment. Addition of surfactant showed increasing improvements on enzymatic hydrolysis-with the solid loading increased from 10% to 25%. With surfactant addition, cellulose conversion increased by 30% at a solid loading of 25%. Finally, Fed-batch hydrolysis with enzymes addition at three times was recommended for high solid loading (25%) hydrolysis. In this condition, the cellulose conversion reached 84%, and the concentrations of glucose and xylose reached 39.5 gl -1 and 7.8 gl -1, respectively. © 2011 American Scientific Publishers. Source

Zhao X.,Shandong Polytechnic University | Deng B.,Shandong Polytechnic University | Mu J.,Shandong Polytechnic University | Li C.,China Oil and Foodstuffs Corporation | And 3 more authors.
Asian Journal of Chemistry

We have identified the phenols, tannins and the primary flavan-3-ol monomers including (+)-catechin, (-)-epicatechin, (+)-gallocatechin grade, (-)-epigallocatechin, (-)-catechin gallate, (-)-epicatechin, gallocatechin gallate and (-)-epigallocatechin gallate in different tissues (flesh, peduncle, skin and seed) of 5 year and 10 year grapevines grape (Cabernet sauvignon) and quantified their content by high performance liquid chromatography. The results show that there were significant differences in the concentration of phenols, tannins and the primary flavan-3-ol monomers among different tissues and grapevine age. Especially, the concentrations of flavan-3-ol monomers were higher in all four grape tissues of 10 year grapevines grape than those of 5 year one. In terms of (-)-catechin gallate, it was detected only in 10 year grapevines grape berry and the flesh of 5-year grapevines grape. The concentrations of (+)- catechin and (-)-epicatechin in the seeds of 10-year grapevines grape were about twice as much as those in 5 year ones. Source

Zhang M.,Beijing Technology and Business University | Zheng J.,China Agricultural University | Ge K.,China Agricultural University | Zhang H.,China Agricultural University | And 5 more authors.
International Dairy Journal

The effect of the size of saccharides on protein structure and antigenicity after glycation was studied. α-Lactalbumin (α-LA) was incubated in a dry state with glucose, maltose or maltooligosaccharides (up to maltopentaose), at 55°C and 65% relative humidity. The extent of glycation, aggregation processes, antigenicity, glycation sites and structural changes were investigated. Structural changes were observed when the protein was incubated with larger saccharides. Furthermore, the degree of glycation decreased with an increase in the size of the saccharide. The antigenicity of all samples significantly decreased when glycation increased, but the greatest reduction of antigenicity was observed with maltotriose-α-LA. By comparing the glycation sites of all the glycated samples, glycation of Lys58 was dominant in glucose-α-LA and maltotriose-α-LA, whose antigenicity reductions were the highest. These results suggest that when the main epitope was glycated, the degree of antigenicity reduction increased with the increase in the size of the saccharide. © 2013. Source

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