The role of calcium in wheat starch-Mesona chinensis polysaccharide gels: Rheological properties, in vitro digestibility and enzyme inhibitory activities

A comparative study on the gel and structural characteristics of starch from three rice varieties when combined with Mesona chinensis polysaccharides

Mesona chinensis polysaccharide (MCP) has excellent gel-forming characteristic, previous studies showed that MCP could affect the gelling and structural properties of rice starch, but the effect of MCP on rice starch from different types is not clarified. In this study, the effects of MCP on the pasting, rheological, and structural characteristics of glutinous rice starch (GRS), japonica rice starch (JRS), and indica rice starch (IRS) were investigated. The results showed that GRS-MCP has the best viscosity, its peak and final viscosities are higher than JRS-MCP and IRS-MCP. The gel network structure was enhanced by MCP in the order of IRS > JRS > GRS, which was reflected by greater elasticity, higher gel strength and hardness, and less free water in JRS-MCP and IRS-MCP. MCP also enhanced the ordered structure and thermal stability of the three starch gels, which is conducive to their application in the market. These findings provide new theoretical insights to produce rice starch-based foods.

Effects of synergistic action on rheological and thermal properties of potato starch complexes co-gelatinized with caffeic acid and squash polysaccharides extracted with water and subcritical water

In order to broaden the application range of squash polysaccharide (WESP/SWESP) and caffeic acid (CAA) and improve the quality of potato starch (PS) products, the effects of WESP/SWESP and CAA on the gelatinization, rheology, thermodynamics, microstructure and in vitro digestion of PS were investigated. Meanwhile, the synergistic effect of WESP/SWESP and CAA on PS was further analyzed. Differently, due to WESP and SWESP had different monosaccharide composition and structure, they had different effects on the system. Pasting properties results showed that the presence of WESP/SWESP and CAA significantly reduced the peak viscosity, trough viscosity, breakdown viscosity and final viscosity of PS, especially under the combined action. In rheological tests, all sample gels belonged to the pseudoplastic fluids and weak gel system (tan δ < 1). Besides, thermodynamic properties revealed that WESP/SWESP and CAA synergistic effect had better retrogradation delay effect. In the ternary system, WESP/SWESP, CAA and PS can form a new network structure and improve the stability of the gel system. In addition, the results of infrared spectroscopy, Raman spectroscopy, x-ray diffraction and scanning electron microscopy exhibited that the ternary system can promote the accumulation and winding of the spiral structure of PS chain, and make the structure of PS gel network more orderly and stable. Furthermore, compared with PS gel, the ternary system had lower RDS and higher SDS and RS content, suggesting that the addition of WESP/SWESP and CAA at the same time was more conducive to reducing the hydrolysis rate of PS. This work revealed the interaction between WESP/SWESP, CAA and PS, which improved the physicochemical and digestive properties of PS. It will provide a theoretical basis for improving the quality of potato starch-related products and developing functional foods.

The Effects of Tremella fuciformis Polysaccharide on the Physicochemical, Multiscale Structure and Digestive Properties of Cyperus esculentus Starch

In this study, we have investigated the effects of Tremella fuciformis polysaccharide (TP) on the pasting, rheological, structural and in vitro digestive properties of Cyperus esculentus starch (CS). The results showed that the addition of TP significantly changed the pasting characteristics of CS, increased the pasting temperature and pasting viscosity, inhibited pasting, reduced the exudation of straight-chain starch and was positively correlated with the amount of TP added. The addition of the appropriate amount of TP could increase its apparent viscosity and enhance its viscoelasticity. The composite system of CS/TP exhibited higher short-range ordered structure and solid dense structure, which protected the crystal structure of CS, but was related to the amount of TP added. In addition, the introduction of TP not only decreased the in vitro digestion rate of CS and increased the content of slow-digestible starch (SDS) and resistant starch (RS), but also reduced the degree of digestion. Correlation studies established that TP could improve the viscoelasticity, relative crystallinity and short-range order of the CS/TP composite gel, maintain the integrity of the starch granule and crystalline structure, reduce the degree of starch pasting and strengthen the gel network structure of CS, which could help to lower the digestibility of CS.

Effects of Kiwifruit Dietary Fibers on Pasting Properties and In Vitro Starch Digestibility of Wheat Starch

In this study, the roles of kiwifruit soluble/insoluble dietary fiber (SDF/IDF, respectively) in the pasting characteristics and in vitro digestibility of wheat starch were explored. According to RVA and rheological tests, the IDF enhanced the wheat starch viscosity, decreased the gelatinization degree of the starch granules, and exacerbated starch retrogradation. The addition of SDF in high quantities could reduce the starch gelatinization level, lower the system viscosity, and exacerbate starch retrogradation. Through determining the leached amylose content and conducing scanning electron microscopy, the IDF and SDF added in high quantities was combined with the leached amylose wrapped around the starch granules, which reduced the leached amylose content and decreased the gelatinization degree of the starch granules. The Fourier transform infrared results showed that the addition of both the IDF and SDF resulted in an enhancement in hydrogen bonding formed by the hydroxyl groups of the system. The in vitro digestion results strongly suggested that both the IDF and SDF reduced the wheat starch digestibility. The above findings are instructive for the application of both IDF and SDF in starchy functional foods.

Effect of polysaccharide addition on food physical properties: A review

The texture, flavor, performance and nutrition of foods are affected by their physical properties during processing, cooking, storage, and shelf life. In addition to chemical, physical, and enzymatic modification methods, polysaccharide addition is also considered a safe, effective, and convenient food modification strategy. However, thus far, literature review on the effects of polysaccharides on the physical properties of foods is few. Therefore, the present work reviews the effects of polysaccharides on water retention capacity, rheological property, suspension ability, viscoelasticity, emulsifying property, gelling property, stability, and starch regeneration and digestion. Furthermore, the existing problems and future recommendations during food physical property modification by polysaccharides are presented. This work aims to provide some theoretical references for future research, development, and application of polysaccharides on food physical property modification.

Effects of zucchini polysaccharide on pasting, rheology, structural properties and in vitro digestibility of potato starch

Zucchini polysaccharide (ZP) has a unique molecular structure and a variety of biological activities. This study aimed to evaluate the effects of ZP (1, 2, 3, 4 and 5 %, w/w) on the properties of potato starch (PS), including pasting, rheological, thermodynamic, freeze-thaw stability, micro-structure, and in vitro digestibility of the ZP-PS binary system. The results showed that the appearance of ZP significantly reduced the peak, breakdown, final and setback viscosity and prolonged the pasting temperature of PS, whereas increased the trough viscosity. The tests of rheological showed that ZP had a damaging effect on PS gels. Meanwhile, the results of thermodynamic and Fourier transform infrared exhibited that the presence of ZP significantly retarded the retrogradation of PS, especially at a higher levels. The observation of the microstructure exhibited that ZP significantly altered the microscopic network structure of the PS gels, and ZP reduced the formation of the gel structure. Besides, ZP postponed the retrogradation process of PS gels. Moreover, ZP weakened the freeze-thaw stability of the PS gel. Furthermore, ZP also can decrease the digestibility and estimated glycemic index (eGI) value of PS from 86.04 % and 70.89 to 77.67 % and 65.22, respectively. Simultaneously, the addition of ZP reduced the rapidly digestible starch content (from 25.09 % to 16.59 %) and increased the slowly digestible starch (from 24.99 % to 26.77 %) and resistant starch content (from 49.92 % to 56.64 %). These results have certain guiding significance for the application of ZP in starch functional food.

Comparison of structures and properties of gels formed by corn starch with fresh or dried Mesona chinensis polysaccharide

Starch is a major dietary carbohydrate, but its digestion properties need to be improved. Mesona chinensis polysaccharides (MCPs) had a unique function in improving the flocculation performance of starch. This study investigated the effects of adding Mesona chinensis polysaccharide extracted from wet fresh and dry plants with one-year storage, namely WMCP and DMCP, on the physicochemical properties and digestion kinetics of corn starch(CS). The composition analysis showed both WMCP and DMCP were an acidic heteropolysaccharide rich in galacturonic acid and galactose, whereas showed different average main fraction molecular weights (Mw) of 47.36 kDa and 42.98 kDa, respectively. In addition, WMCP showed higher yield, purity and better physicochemical properties to CS than DWCP. Thermal analysis showed WMCP decreased more gelatinization temperatures and enthalpy of CS, and increased more freeze-thaw stability, water holding capacity, and textural parameters of CS gels than DMCP. Structural analysis revealed WMCP induced more changes in crystallinity, short-range order, and microstructure of CS, which inhibited retrogradation than DMCP. In vitro digestion assays demonstrated WMCP addition significantly increased higher resistant starch content by altering starch-starch and starch-MCP interactions than DWCP. Overall, MCPs addition beneficially modulated CS properties and digestion kinetics, providing a novel way to improve starch functionalities. Moreover, WMCP had more advantages to be chosen to form hydrocolloid with CS than DMCP.

Physicochemical properties and in vitro hypoglycemic activities of hsian-tsao polysaccharide fractions by gradient ethanol precipitation method

Hsian-tsao polysaccharides fractions (HPs), including HP20, HP40, HP60, and HP80, were fractioned by gradient precipitation of 20 %, 40 %, 60 %, and 80 % (v/v) ethanol, respectively. Their physicochemical properties and in vitro hypoglycemic activities (inhibitory activities on α-amylase and α-glucosidase, glucose adsorption capacity, and glucose diffusion retardation) were determined. The results showed that, with ethanol upward, the average particle size, molecular weight, and apparent viscosity of HPs were decreased while carbohydrate and uronic acid contents, absolute zeta potential, and thermal stability were increased. Each of the HPs contained Rha, Ara, Gal, Xyl, Man, and GalA with different molar ratios, indicative of anionic heteropolysaccharides with uronic acid. HPs, with diverse structures and surface morphologies as proved by FTIR and SEM, whose solutions were pseudoplastic fluids, exhibited elastic behavior of weak gel networks at concentrations of >1 %. Moreover, HPs showed inhibitory activities on α-amylase and α-glucosidase, of which HP80 was the strongest. For α-amylase, HP20 and HP60 behaved as mixed inhibitors, while HP40 and HP80 were non-competitive. For α-glucosidase, HPs acted as mixed inhibitors. Additionally, HPs possessed glucose adsorption capacity and glucose diffusion retardation, with the best for HP20. These results suggested that HPs possessed hypoglycemic activities, which could be developed as functional food or hypoglycemic drugs.

Hydrolase activity and microbial community dynamic shift related to the lack in multivalent cations during cation exchange resin-enhanced anaerobic fermentation of waste activated sludge

The correlation of the lack in multivalent cations with hydrolase activity and microbial community in anaerobic fermentation of waste activated sludge was investigated in this study. It was demonstrated that considerable solid phase reduction of 41 % (7.87 g/L) was achievable through a cation exchange resin-enhanced anaerobic fermentation of 4 days. The protease and α-glucosidase, especially α-glucosidase, were easily influenced by a lack in multivalent cations. Furthermore, species abundance and diversity of microbial community gradually decreased. Meanwhile, the bacteria community structure presented obvious dynamic shifts. Ruminococcaceae_UCG_009, Bacteroides and Macellibacteroides responsible for organic matter biodegradation and SCFAs production became dominant bacteria in cation exchange resin-enhanced anaerobic fermentation, which was less influenced by the lack in multivalent cations, while the SCFA consumers (e.g. methanogens) were inhibited with reduced abundances due to their susceptibility to the lack in multivalent cations. Redundancy analysis revealed that the lack in multivalent cations were responsible for the microbial community evolution, which was proved by the high Grey relational coefficients (0.747-0.820) and significant negative Spearman coefficients (-0.5798 to -0.9429) between multivalent cation and microbial community. Obviously, the cation exchange resin-induced removal of multivalent cations reduced enzyme activity and modified microbial community structure, which created a beneficial environment for enhancing anaerobic fermentation.