Pea soluble polysaccharides obtained from two enzyme-assisted extraction methods and their application as acidified milk drinks stabilizers.

The objective of this work was characterize and evaluate the protein-stabilizing property of pea soluble polysaccharide (PSPS) extracted from pea by-products using spray-drying and ethanol precipitation oven drying, obtaining PSPS-A and PSPS-B, respectively. The weight average molecular weight (Mw) of PSPS-A and PSPS-B were 625 kDa and 809 kDa, respectively. The results of Fourier transform infrared spectroscopy (FT-IR) analysis indicated that PSPS-A, PSPS-B and soybean soluble polysaccharide (SSPS) contained the same functional groups. The absolute negative charges of PSPS-A or PSPS-B in aqueous solution were slightly higher than that of SSPS at pH 2.0 to 7.0. The apparent diameter of PSPS-B (479.1 nm) was larger than that of PSPS-A (127.7 nm) and SSPS (209.5 nm) were measured by dynamic light scattering. The AFM images revealed that both PSPS-A and PSPS-B possessed star-like structures with more side chains as compared to SSPS. It was found that the addition of 0.15% PSPS-A or 0.1% PSPS-B was adequate to prevent the aggregation of protein and obtain stable dispersion. Furthermore, PSPS has a wider pH range (pH 3.6-4.6) to stabilize milk protein than SSPS (pH 3.6-4.2).

The influence of heat treatment on acid-tolerant emulsions prepared from acid soluble soy protein and soy soluble polysaccharide complexes.

This research presents a green procedure to prepare oil in water (O/W) emulsion from acid soluble soy protein (ASSP) and soy soluble polysaccharide (SSPS), a long-term stable nanoscale system for delivering the lipophilic components. The emulsion technique involved the preparation complexion using ASSP and SSPS by electrostatic and hydrophobic interactions as well as high pressure homogenization. The average diameter of the droplet of emulsions (fresh and heated) is 263±2nm. Such emulsions resulted in heating stable dispersions containing corn oil at the concentration of 20.0%, even at the pH around the isoelectric points of ASSP. After 90days storage at 4°C, the mean diameter of emulsions after heating at 80°C for 60min is 314±1nm compared with 341±3nm of emulsions unheated. The heat-stability of dispersions were affected by emulsion conditions, so the present research demonstrates the emulsion stability against heat treatment, ionic strength and pH change.

Fabrication and Characterization of Stable Soy ß-Conglycinin-Dextran Core-Shell Nanogels Prepared via a Self-Assembly Approach at the Isoelectric Point.

The preparation of soy ß-conglycinin-dextran nanogels (∼90 nm) went through two stages, which are safe, facile, and green. First, amphiphilic graft copolymers were formed by dextran covalently attaching to ß-conglycinin via Maillard dry-heating reaction. Second, the synthesized conjugates were heated above the denaturation temperature at the isoelectric point (pH4.8) so as to assemble nanogels. The effects of pH, concentration, heating temperature, and time on the fabrication of nanogels were examined. The morphology study displayed that the nanogels exhibited spherical shape with core-shell structures, which was reconfirmed by zeta-potential investigation. Both circular dichroism spectra and surface hydrophobicity analyses indicated that the conformations of ß-conglycinin in the core of nanogels were changed, and the latter experiment further revealed that the hydrophobic groups of ß-conglycinin were exposed to the surface of protein. The nanogels were stable against various conditions and might be useful to deliver hydrophobic bioactive compounds.

Estimation of the distribution of Tabebuia guayacan (Bignoniaceae) using high-resolution remote sensing imagery.

Species identification and characterization in tropical environments is an emerging field in tropical remote sensing. Significant efforts are currently aimed at the detection of tree species, of levels of forest successional stages, and the extent of liana occurrence at the top of canopies. In this paper we describe our use of high resolution imagery from the Quickbird Satellite to estimate the flowering population of Tabebuia guayacan trees at Barro Colorado Island (BCI), in Panama. The imagery was acquired on 29 April 2002 and 21 March 2004. Spectral Angle Mapping via a One-Class Support Vector machine was used to detect the presence of 422 and 557 flowering tress in the April 2002 and March 2004 imagery. Of these, 273 flowering trees are common to both dates. This study presents a new perspective on the effectiveness of high resolution remote sensing for monitoring a phenological response and its use as a tool for potential conservation and management of natural resources in tropical environments.

Synthesis, chiral resolution, and determination of novel furan lignan derivatives with potent anti-tumor activity.

A kind of racemic furan lignans were synthesized via a novel route, and two optical isomers were obtained through a selective hydrolization. The absolute configurations were determined by circular dichroism spectroscopy after separated through a preparative column. The different activities of isomers and the racemates were evaluated on QGY-7701 and HeLa cell lines, and compound 2c showed the best activity on QGY-7701 and HeLa cell lines with IC(50) 12 microM and 13 microM, respectively.