Textural properties of mung bean starch gels prepared from whole seeds

Effects of Premna microphylla turcz polysaccharide on rheological, gelling, and structural properties of mung bean starch and their interactions

The aim of this study was to investigate the effects of Premna microphylla turcz polysaccharide (PMP) on the rheological, gelling, and structural properties of mung bean starch (MBS) and their potential interaction mechanism. Results showed that the addition of PMP significantly improved the pasting properties, rheological properties, water holding capacity, and thermostability of MBS. The texture tests showed a decrease in hardness, gumminess and chewiness, indicating the retrogradation of MBS was inhibited. Scanning electron microscopy (SEM) suggested the MBS-PMP composite gels expressed a denser microstructure with obvious folds and tears. Moreover, the results of X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and interaction force tests revealed the main forces between MBS and PMP were hydrogen bonds and hydrophobic interactions to form composite gels with great gelling properties. These results facilitate the practical application of MBS and PMP, and provide some references for understanding the interaction mechanism between starch and polysaccharide.

Rheological, textural, and water-immobilizing properties of mung bean starch and flaxseed protein composite gels as potential dysphagia food: The effect of Astragalus polysaccharide

The effects of Astragalus polysaccharide (APS) on rheological, textural, water-holding, and microstructural properties of mung bean starch (MBS)/flaxseed protein (FP) composite gels were investigated. Results showed that the storage modulus (G') of gels with APS were significantly lower than that of the control gel, while different concentrations of APS possessed diverse effects on the hardness, gumminess and cohesiveness of the gels. Adding APS significantly improved the water retention capacity by trapping more immobilized and free water in the gel network. Microstructurally, the MBS/FP/APS composite gels displayed a complex network with reduced pore size compared with that of the control gel (MBS/FP). International dysphagia diet standardization initiative (IDDSI) tests suggested that gels with APS contents below 0.09 % could be classified into level 6, while gel with 0.12 % APS could be categorized as level 7. Mechanistically, APS could influence the interactions between starch and protein within the tri-polymeric composite systems by affecting starch gelatinization and hydrogen bonding, further contributing to the formation of strengthened gel network and the change of gel properties. These results suggest that the macromolecular APS can improve the structural and textural properties of the starch-protein composite systems, and impart various functional properties to the FP-based gel foods.

Textural characterization of calcium salts-induced mung bean starch-flaxseed protein composite gels as dysphagia food

Effects of calcium gluconate (CG), calcium lactate (CL) and calcium dihydrogen phosphate (CDP) on the structural and functional properties of mung bean starch (MBS)-flaxseed protein (FP) composite gels were investigated to explore the feasibility of developing dysphagia food. The water-immobilizing, rheological and structural properties of MBS-FP composite gels adding different calcium salts (10, 30, and 50 mmol/L) were analyzed by low-field nuclear magnetic resonance measurement, rheological and textural analyses, fourier transform infrared spectroscopy, scanning electron microscopy and confocal laser scanning microscopy. Results showed that calcium salts imparted various soft gel properties to the composite gels by influencing the interactions between MBS and FP. Calcium salts could affect the conformation of amylose chains, accelerate the aggregation of FP molecules, and increase the cross-linking between starch and protein aggregates, resulting in the formation of large aggregates and a weak gel network. Consequently, calcium salts-induced composite gels showed lower viscoelastic moduli and gel strength than the control gel. In particular, different calcium salts had various impacts on the gel properties due to their diverse ability forming hydrogen bonds. Compared with CL and CDP, the gels containing CG presented the higher viscoelastic moduli and hardness, and possessed an irregular cellular network with the increased pore number and the decreased wall thickness. The gel containing 50 mmol/L CL had the highest water-holding capacity, in all the gels tested, by retaining more immobilized and mobile water in the compact gel network with larger cavities. The gels adding CDP presented lower hardness and gumminess due to the obvious lamellar structure within the network. International dysphagia diet standardization initiative (IDDSI) tests indicated that the gels adding CG and CL could be categorized into level 6 (soft and bite-sized) dysphagia diet, while the samples adding CDP could be classified into level 5 (minced and moist). These findings provide insights for the development of the novel soft gel-type dysphagia food.

Properties and Digestibility of Octenyl Succinic Anhydride-Modified Japonica-Type Waxy and Non-Waxy Rice Starches

Waxy and non-waxy rice starches from japonica type Korean rice varieties were esterified with different levels of octenyl succinic anhydride (OSA), and the molecular structure of amylopectin (AP), digestibility, and emulsion stability were investigated. As OSA levels increased, the degree of substitution, granule size, peak and final viscosities, emulsion stability, and short chain of AP increased. However, the gelatinization temperature and enthalpy, and digestibility decreased. All OSA esterified starches showed a new band at 1723 cm-1, but maintained A-type crystallinity. The DP6-12 of AP in waxy rice starch (WRS) was higher than that in non-waxy rice starch (NRS) with increasing OSA levels. Because the amylose and long chain of AP accessed easily with OSA groups, the digestibility of NRS was lower than that of WRS. The emulsion stability was higher in WRS than in NRS. From the above results, it is suggested that amylose should have a higher affinity with OSA esterification than AP and that the emulsion stability should increase in WRS, but the digestibility should decrease in NRS after OSA modification.