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The aim of this study was to evaluate the effects of alcohol-acid degradation on the structural and physicochemical characteristics of guar gum. Guar gum (50 wt.%) was treated with methanol, ethanol, 2-propanol, or 1-butanol containing 1 or 2 mL 36% hydrochloric acid at 75 °C for 30–240 min. The linear relationship between 1/Mw and time suggested that alcohol-acid degradation followed first-order kinetics with rate constants varying directly with the number of alcohol carbon atoms and acid concentration. Alcohol-acid treatment exerted no effect on the chemical and crystal structure of guar but significantly decreased shear viscosity, slightly increased solubility, mildly reduced thermostability, and dramatically darkened colour. This study extended the knowledge of the effect of alcohol on the acid hydrolysis of guar and will contribute to the development of a large-scale procedure for guar gum degradation. [ABSTRACT FROM AUTHOR]

Waxy maize starch (WMS) was modified using sequential α-amylase and transglucosidase to create enzyme-treated waxy maize starch (EWMS) with higher branching degree and lower viscosity as an ideal healing agent. Self-healing properties of retrograded starch films with microcapsules containing WMS (WMC) and EWMS (EWMC) were investigated. The results indicated that EWMS-16 had the maximum branching degree of 21.88 % after transglucosidase treatment time of 16 h, and A chain of 12.89 %, B1 chain of 60.76 %, B2 chain of 18.82 % and B3 chain of 7.52 %. The particle sizes of EWMC ranged from 2.754 to 5.754 μm. The embedding rate of EWMC was 50.08 %. Compared to retrograded starch films with WMC, water vapor transmission coefficients of retrograded starch films with EWMC were lower, while tensile strength and elongation at break values of retrograded starch films were almost similar. Retrograded starch films with EWMC had higher healing efficiency of 58.33 % as compared to that Retrograded starch films retrograded starch films with WMC was 44.65 %. [ABSTRACT FROM AUTHOR]

The effects of induced electric field (IEF) on the crystal structure and physicochemical properties of potato starch were investigated by subjecting identically treated control and electrically-modified samples to the same temperature history. Additionally, a method of combining IEF with heating for efficient modification of native polymer was also proposed. Results showed that the application of IEF at an electric voltage of 75 V has a statistically significant effect on starch gelatinization and pasting properties, especially when combined with heating at 50 °C. After treatment by the combination method for 96 h, the gelatinization temperatures increased, which can be explained by the slight increase in the ratio of 1044/1015 cm −1 and relative crystallinity. Furthermore, IEF reduced granular swelling and therefore contributed to decreasing the peak, breakdown, and setback viscosity of potato starch. This study explores the potential of IEF as innovative technology for starch modification. [ABSTRACT FROM AUTHOR]

Abstract: The aims of this study were to investigate the interaction between β-cyclodextrin (β-CD) and amylose–lipid complex in retrograded starch and to propose a model related to the interaction for exploring the retardation of β-CD on starch retrogradation. Results obtained from differential scanning calorimetry (DSC) and X-ray diffraction (XRD) showed that β-CD competed with amylose to disrupt the formation of amylose–lipid complex and that a potential amylose–β-CD–lipid inclusion complex was formed in the retrograded starch. The formation of the complex obviously caused the association of starch chains due to the short and fat aggregates observed using atomic force microscopy (AFM). These findings indicated that the formed amylose–β-CD–lipid complex was responsible for the retardation of starch retrogradation. [Copyright &y& Elsevier]

• Innovative contactless thermal effect on starch hydrolysis was investigated. • Starch acidolysis solution acts as the coils of a transformer for heating treatment. • Innovative inner heating method accelerated corn starch acid hydrolysis. • The treated starch had increased solubility and swelling power. • Thermal effect of induced electric field altered the physicochemical properties of starch. Growing attention has been focused on modifications of starch using electric field, but electrode corrosion and metal contamination remain unavoidable during the process. To solve these problems, the magneto-induced electric field was used to assist corn starch hydrolysis due to its thermal effect. Results indicated that the method accelerated corn starch acid hydrolysis and decreased the treatment time. The reducing sugar content increased to 0.59 g/L after a 60 s treatment, which was 353.44 % higher than the 20 s treatment, while the average degree of polymerization reached a minimum. The treated starch showed increased solubility and swelling power, as well as decreased freeze-thaw stability. X-ray diffraction, fourier transform infrared spectroscopy, and scanning electron microscopy results suggested that the physicochemical changes of corn starch were due to the thermal effect of the induced electric field. This study is expected to provide an important basis for applying new electric field hydrolysis technology to starch modification. [ABSTRACT FROM AUTHOR]

This study aimed to improve the effect of moderate electric field (MEF) treatment on the structural and physicochemical properties of maize starch by adding 1-butyl-3-methylimidazolium chloride ([bmim]Cl). Starch (20%, w/v) was mixed with [bmim]Cl solution (0, 30%, 50%, and 70%, w/w), and then electro-treated (5 V/cm, 50 Hz) at 60 °C for 10 min. As the [bmim]Cl concentration increased, the electro-induced disintegration of starch granules was enhanced due to the intensified Joule heat and decreased pH of reaction bulk. After electro-treated in 70% w/w [bmim]Cl, a transparent solution of starch was observed and the recovered starch tended to dissolve rather than swell in water. Compared with water-bath heating, MEF caused more destruction in the granular and crystal structure, increased the particle size, decreased the pasting viscosity, and reduced the gelatinization enthalpy and thermostability of starch. The obtained results could provide guidance for the application of electro-based techniques in starch modification. [Display omitted] • Moderate electric field (MEF) intensified the destruction of maize starch in [bmim]Cl. • The intensification was improved with increasing concentration of [bmim]Cl. • Starch granules were disintegrated by MEF treatment in 70% w /w [bmim]Cl. • Starch tended to dissolve rather than swell after MEF treatment in 70% w/w [bmim]Cl. [ABSTRACT FROM AUTHOR]

Large-ring cyclodextrins (LR-CDs) have a number of intriguing properties for potential use in pharmaceutical and food industry. To date, no colorimetric method has been reported for LR-CD content quantification. In this study, triple wavelength colorimetry (TWC) and orthogonal-function spectrophotometry (OFS) have been successfully applied to determine ingredient concentrations in a mixture of amylose and LR-CDs. Both TWC and OFS yielded precise amylose content data in good agreement with expected values. For quantification of LR-CD content, OFS provided a higher accuracy than TWC, which resulted in a slight over-determination. As a comparison, single-wavelength colorimetry performed at the corresponding absorption maximum led to a significant over-determination of both amylose and LR-CD contents. The validity of TWC and OFS allowed their application for discriminative detection of the cyclization and total activity of a 4-α-glucanotransferase (4αGTase) from Thermus aquaticus regarding the synthesis of LR-CDs and the conversion of amylose to small molecules, respectively. High pressure size exclusion chromatography analysis of the post-reaction mixtures following 4αGTase-catalyzed conversion of amylose revealed the presence of linear malto-oligosaccharides in the LR-CD fraction. By introduction of a correction factor, the interference caused by linear malto-oligosaccharides was eliminated for a more accurate determination of LR-CD cyclization activity. [ABSTRACT FROM AUTHOR]

Abstract: Food grade biopolymers, such as dextrin, have been suggested as a technological solution for the controlled delivery of health promoting substances. The main focus of this work is to improve the stability of poly-unsaturated fatty acids (PUFAs) and controlled release by encapsulating with helical spring dextrin (SD). The encapsulation was formed between SD with a of 62 and α-linolenic acid (ALA) or linoleic acid (LA) at 60°C and characterized by WXRD, DSC, TGA and SEM. Under conditions which simulated the human environment of the gastrointestinal system, 21.7% and 18.5% of SD–ALA and SD–LA were released, respectively. A molecular dynamics simulation indicated that the space of helix cavity for ALA–SD complex was larger than that for LA–SD complex. This research work supports the idea that these complexes not only can improve the stability of ALA and LA, but also can achieve the targeted delivery of functional lipids or other bioactive components to the small intestine. [Copyright &y& Elsevier]

• Preparation of high content galactomannan hydrogel. • Effect of galactomannan content on hydrogel properties. • BAC, as a redox-responsive crosslinker, can regulate hydrogel degradation and drug release. • Hydrogen bond and chemical bond can give GA-PAM-BAC hydrogel elasticity and fatigue resistance. An oxidation-reduction responsive degradable highly elastic galactomannan hydrogel was synthesized from galactomannan (GA), N,N -bis (acryloyl) cysteamine (BAC) and acrylamide by grafting polymerization in aqueous solution. The microstructure, degradability and mechanical properties of the hydrogels were emphatically investigated using Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), ultraviolet spectroscopy and differential scanning calorimetry (DSC). The mechanical properties of hydrogels can be improved by adjusting the content of GA. Continuous cyclic compression tests showed that the hydrogel did not rupture under 60 %,70 %,80 % strain and quickly recovered to its original shape. The degradation rate and drug release rate of hydrogel can be adjusted by the concentration of the reductant and the reduction time. These hydrogels broaden the scope of application of GA and can be tuned with a broad range of mechanical, degradation and release properties and therefore hold potential applications in drug carriers, tissue engineering scaffolds, extracellular matrix and other fields. [ABSTRACT FROM AUTHOR]