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

Separation of principal component dihydromyricetin from Ampelopsis grossedentata by high-speed counter-current chromatography and its interaction with corn starch

Ampelopsis grossedentata (AG) is an industrial crop in the grape family, which has been used as a dual-purpose plant for medicine and tea with high medicinal values. However, little is reported on the separation technology of active components from AG and processing technology of AG products. High-speed counter-current chromatography (HSCCC) was applied to separate the principal component dihydromyricetin (DMY) from AG. DMY is added to starch-based products to improve food quality. The interaction between corn starch (CS) and DMY was investigated to predict and control the structure and function of starch-based foods. Results show that DMY with 97.13% purity was successfully obtained by HSCCC using a solvent system composed of light petroleum-ethyl acetate-methanol-water-trichloroacetic acid (1:3:1:3:0.01, v/v/v/v/v). Fourier-transform infrared spectroscopy (FT-IR) exhibits that the interactions between CS and DMY included hydrogen bond and noncovalent bond. X-ray diffraction (XRD) shows that DMY could increase the relative crystallinity of CS. Low-field nuclear magnetic resonance results (LF-NMR) imply that DMY decreased the spin relaxation time (T₂ ) and inhibited the mobility of free water. Atomic force microscopy (AFM) results suggest that DMY changed the surface morphology of CS through hydrogen bond interaction. Moreover, the results of confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM) indicate that DMY could enlarge the pores and change the microstructure of CS-DMY complexes. The findings promote the development of industrial CS-based products and utilization of corn crop.

Separation of gallic acid from Cornus officinalis and its interactions with corn starch

D101 macroporous resin combined with high speed counter-current chromatography (D101 MR-HSCCC) was used to separate gallic acid (GA) from Cornus officinalis, and GA was added to starch-based products to improve food quality. The interaction and action mechanism of corn starch (CS) with GA were investigated for prediction and thereby controlling the structure and functions of starch-based foods. Results show that GA with 98.72% purity was successfully obtained using the D101 MR-HSCCC technique. HSCCC solvent system was composed of n-hexane-ethyl acetate-methanol-water (1:5:1:5, v/v/v/v). GA inhibited CS dissolution and improved CS swelling. Based on the particle size distribution, GA could enlarge the size of CS-GA complexes. FT-IR spectra exhibit that the interactions between CS and GA may comprise the intermolecular hydrogen bond and non-covalent bond. The results of XRD, LF-NMR and AFM show that the presence of GA could increase the relative crystallinity of CS, decrease the spin relaxation time (T₂)_, and change the surface morphology of CS via the modification of hydrogen bonds distribution. Finally, SEM analysis indicates that GA could change the microstructure of CS-GA complexes. These findings facilitate the development of CS-based products and utilization of CS.

Mechanochemical effects on the structural properties of wheat starch during vibration ball milling of wheat endosperm

Pure wheat endosperm was fully ground in a vibratory ball mill and structural changes in wheat starch were measured to assess the effect of mechanochemical action during the grinding process. Vibratory ball milling changed the endosperm granule size to ~30 μm (D50). There was a significant increase in damaged starch content, and this was positively correlated with the grinding time. The relative crystallinity of starch decreased by 5% after milling 105 min, and the short-range order decreased. The damaged structure of amylopectin starch decreased with milling time, as detected macroscopically by the peak viscosity and final viscosity of milling samples. Overall, the in vitro digestion results showed that mechanical modification caused irregular defects inside wheat starch crystals, increased the sensitivity of wheat starch to enzymes, enhanced the hydrolysis rate three-fold, and increased the maximum starch hydrolysis by 50%. Mechanochemistry effects was used to analyze the quality changes in wheat milling.

Effects of konjac glucomannan on pasting, rheological, and structural properties of low-amylose rice starch

Blend of starch and polysaccharide is a secure and feasible modifying method for starch. Effects of konjac glucomannan (KGM) on pasting, retrogradation, rheological and structural properties of low-amylose rice starch were evaluated. KGM addition reduced the pasting temperature, breakdown and setback values, but raised the peak viscosity. When KGM concentration increased, the storage and loss moduli showed an upward trend. Fourier transform infrared spectroscopy (FTIR) showed redshifts at 3450 and 1640 cm−1 and suggested the formation of intermolecular hydrogen bond between KGM and starch molecules. X-ray diffraction (XRD) indicated that KGM decreased the relative crystallinity from 11.88 to 3.10%. Scanning electron microscopy (SEM) of KGM induced samples showed looser network structures, and confocal laser scanning microscopy (CLSM) detected less cloud-like blurry pastes surrounding around the starch ghosts. KGM addition suppressed the starch retrogradation. These results could be used to broaden the application of KGM in the food industry.

Dry heat treatment induced the gelatinization, rheology and gel properties changes of chestnut starch

The effects of continuous dry heat treatment (CT) and repeated dry heat treatment (RT) on gel and structural properties of chestnut starch (CS) were investigated. CT and RT both reduced the swelling degree of starch and showed significant variations in pasting viscosity, viscoelasticity, gel strength and hardness varying from high to low after dry heat treatment, and CT was lower than that of RT. Neither dry heat treatment nor gelatinization produced new functional groups, and both reduced short-range ordered degree. There were significant decrease in spin-spin relaxation time (T₂) with dry heat treatment (CT and RT), which made the starch in the samples closely combine with water. These results are helpful to better understand the changes of physicochemical properties of starch gel products during dry heat treatment and provide some theoretical references for the application of CS in food industry.

Effects of Auricularia auricula-judae polysaccharide on pasting, gelatinization, rheology, structural properties and in vitro digestibility of kidney bean starch

Auricularia auricula-judae polysaccharide (AP) has unique molecular structures and multiple bioactivities with excellent gel-forming property and thermal tolerance. However, few researches focus on the interactions between AP and legume starches. In this study, the effects of AP on the pasting, gelatinization, rheology, microstructure, and in vitro digestibility of kidney bean starch (KBST) were evaluated. The pasting, gelling and structural properties of AP-KBST mixtures were characterized by rapid visco analyzer, rheometry, texture analyzer, laser particle analyzer, low-field nuclear magnetic resonance, Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. And an in vitro method was employed to measure the digestibility of AP-KBST composites. The pasting viscosity, swelling degree of starch granules, viscoelasticity, gel strength, cold storage stability and water-retention capacity of KBST were enhanced with increasing AP concentration. The combination of AP and KBST exhibited a higher short-range ordered and a firmer and denser structure than that of KBST alone. Moreover, AP increased the contents of resistant starch and slowly digestible starch, which were positively correlated with the storage modulus and the degree of order, thereby suggesting that the formation of strong and ordered gel network structure by synergistic interactions between AP and KBST was responsible for the reduced starch digestibility.

Gelatinization, Retrogradation and Gel Properties of Wheat Starch-Wheat Bran Arabinoxylan Complexes

Gelatinization, retrogradation and gel properties of wheat starch–wheat bran arabinoxylan (WS–WBAX) complexes have been evaluated. The results of rapid viscosity analyzer (RVA), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR) confirmed that WBAX samples with larger Mw and branching degree (HWBAX) significantly impeded gelatinization process of starch by effectively reducing the amount of water available for starch gelatinization. DSC analysis showed that both molecular characteristics and additive amount of WBAX samples have an effect on the long-term retrogradation behavior of starch. For the rheological studies of WS–WBAX mixed gels, the elastic moduli (G’) and shear viscosity of WS–WBAX mixed gels increased with the increase in additive amount of WBAX. WS–HWBAX mixed gels exhibited the lower G’ compared with starch gels containing WBAX with lower Mw and branching degree (LWBAX) at the same amount. The scanning electron micrographs (SEM) revealed that the microstructures of WS–WBAX mixed gels were mainly affected by the amount of WBAX, but hardly by the molecular characteristics of WBAX. Texture profile analysis (TPA) showed that the cohesiveness of fresh WS–WBAX mixed gels became larger with an increase in the WBAX addition amount. The hardness of WS–WBAX mixed gels tended to increase over the 14-day storage.

Anti-freezing starch hydrogels with superior mechanical properties and water retention ability for 3D printing

As a novel material that can be used at subzero temperatures, anti-freezing hydrogels have been attracting extensive attention. Inspired by the freeze-tolerance phenomenon in seawater, which is achieved by mixing salts into water, an ionic compound (CaCl₂) was used to gelatinize starch to form anti-freezing hydrogels. Native potato starch (NPS) anti-freezing hydrogels were formed at -10 °C, -18 °C, -30 °C, and - 50 °C with 6-9 kPa tensile strength and 100-230% elongation at break. The compressive stress of anti-freezing hydrogels at different environmental temperatures increased from 18.586 kPa to 36.551 kPa with the glass transform temperature of starch hydrogels dropped to -50 °C. The anti-freezing hydrogels showed excellent water retention ability, which could maintain a water content of 55% after 7 days at ambient temperature. The prototyping of anti-freezing starch hydrogels broadens the applications of starch in food, adhesives, medical materials, and intelligent materials.

Interaction between rice starch and Mesona chinensis Benth polysaccharide gels: Pasting and gelling properties

Interactions between starch and non-starch polysaccharides are very important for predicting and controlling the structure and function of starch-.based products. In this study, the effects of Mesona chinensis Benth polysaccharide (MCP) on the pasting, rheological, structural, and water mobility properties of rice starch (RS)-MCP gels were evaluated. Results indicated that MCP can increase the pasting viscosity, and gel properties of RS-MCP gels. Rheological results showed that RS-MCP gels exhibited shear-thinning behavior and that MCP can enhance the viscoelasticity of RS-MCP gels. Fourier-transform infrared spectra results indicated no covalent interaction between RS and MCP, and MCP could increase the degree of short-range order of RS-MCP gels. MCP also enhanced the water-retention capacity of RS-MCP gels. Scanning electron microscopy results suggested that MCP could decrease the pore sizes of RS gels and the microstructure of RS gels became more ordered at 0.1 % concentration of MCP. The results suggested that the amylose and MCP molecules interacted through hydrogen bonds and electrostatic forces, which enhanced the gelling properties of RS-MCP gels. Overall, this study shows the potential applications of MCP, and also provides the theoretical basis of interactions in starch-hydrocolloids systems.