Effects of Mesona chinensis polysaccharide on the thermostability, gelling properties, and molecular forces of whey protein isolate gels.

The effects of Mesona chinensis polysaccharide (MCP) on the water holding capacity (WHC), thermostability, rheological properties, microstructure, and molecular forces of MCP-whey protein isolate (WPI) gels were investigated. Results showed that the MCP-WPI gels had higher WHC, thermal stability, and thermal transition temperature than the WPI gel. The apparent viscosities, loss modulus (G″), and storage modulus (G') of the MCP-WPI gels were increased with the MCP concentration. Creep recovery experiment showed that the recovery rate increased with the MCP increased, and MCP-WPI gels had good elasticity and rigid structure. Texture profile analysis (TPA) results showed that gel strength and rupture stress were increased with the MCP addition. Scanning electron microscope (SEM) showed that dense water cavity was formed when the MCP concentration reached 2.0 %. The main molecular forces of the gels were disulfide, hydrophobic, and hydrogen bonding interaction. MCP played a critical role in the formation of MCP-WPI gels.

Effect of Mesona chinensis polysaccharide on the pasting, rheological, and structural properties of tapioca starch varying in gelatinization temperatures.

The effects of Mesona chinensis polysaccharide (MCP) on the pasting, rheological properties, granule size, and water mobility of tapioca starch (TS) were investigated at different gelatinization temperatures (75 °C and 95 °C). The structures of tapioca starch-Mesona chinensis polysaccharide (TM) gels formed at different gelatinization temperatures were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Results showed that the peak, trough, and final viscosities of TM-95 mixtures were lower than that of TM-75 mixtures. Addition of MCP had a significant reduce (p < 0.05) on the granule size and transversal relaxation time of TM mixtures at the two gelatinization temperatures. Rheological analysis also showed that the addition of MCP increased the consistency indexes (K) and decreased the flow behavior indexes (n) of TM-95 and TM-75 gels. XRD results confirmed the diffraction peak of TM-95 gels became blunt and wider, and the diffraction peak at 17° and 23° of TM-75 gels could be observed after MCP added. In addition, the microstructures of TM-75 gels were more compact than that of TM-95 gels. These results can promote the development of TS-based products and application of MCP at different gelatinization temperatures.

Effect of Mesona chinensis polysaccharide on pasting, rheological and structural properties of corn starches varying in amylose contents.

Waxy corn starch (WS), normal corn starch (NS), and high amylose corn starch (HS) were used to investigate the effect of Mesona chinensis polysaccharide (MCP) on pasting, rheological, and textual properties of corn starches. Corn starches (6 %, w/v)-MCP (0.05 %, 0.1 %, 0.2 %, 0.3 %, and 0.5 %, w/v) blended systems were used. The pasting viscosity of samples increased after adding MCP, and the improvement effect was most noticeable in WS-MCP system. Meanwhile, MCP can significantly promote the gelatinization and strengthen viscoelasticity of HS-MCP system. MCP inhibited the dissolution of NS and the swelling of WS, while promote the dissolution of HS and WS, as well as the swelling of NS and HS. Furthermore, gelatinization treatment decreased the crystallinity of samples, while high concentration of MCP slightly increased the crystallinity. MCP could promote the formation of a more ordered structure of blended systems, especially for WS-MCP system.

Physicochemical, rheological and thermal properties of Mesona chinensis polysaccharides obtained by sodium carbonate assisted and cellulase assisted extraction.

Mesona chinensis has been used as a Chinese folk medicine and main ingredient used to make "black bean jelly" in Asia for hundreds of years. In this study, two polysaccharides (MCP-C and MCP-S) from Mesona chinensis were extracted by using cellulase assisted extraction (CAE) and sodium carbonate assisted extraction (SAE), separately. Then the different physicochemical characteristics, rheological and thermal properties of two polysaccharides were analyzed by ion chromatography, high-performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), rheological and thermogravimetric analysis. Results indicated that the contents of total sugar and uronic acid of MCP-C were higher than MCP-S, while the protein content and molecular weight was lower than that of MCP-S. MCP-S and MCP-C had differences in the surface morphology by SEM, while they all had the typical IR spectra characteristic and amorphous morphology of polysaccharides. The rheological experiments showed that MCP-C and MCP-S exhibited typical pseudoplasticity fluids behavior. The apparent viscosity (η), storage modulus (G') and complex viscosity (η*) of MCP-S were higher than MCP-C. The three-stage decomposition patterns were observed in MCP-C and MCP-S. MCP-S was more stable and had higher initial decomposition temperature (Ti) than MCP-C.

Effect of Mesona chinensis polysaccharide on the pasting, thermal and rheological properties of wheat starch.

In this study, the effects of Mesona chinensis polysaccharide (MCP) on the pasting, thermal, rheological, and textural properties of wheat starch were investigated. Rapid viscosity analysis results showed that MCP protects the integrity of starch granules at low concentration in the early stage of pasting. The gelatinization temperature of wheat starch-MCP gels was markedly increased with the increase in polysaccharide concentration, whereas gelatinization enthalpy (ΔHgel) decreased. Rheological analysis showed that the starch:MCP = 8.5:1.5 system exhibited a strong thixotropic property and the highest G' and G″ among the other systems. The same results were observed in the textural experiment, indicating the existence of strong intermolecular interactions between starch granules and MCP. These results indicated that MCP can improve the thermal stability in the early stage of pasting and enhance the rheological properties of wheat starch.