Insight into the multi-scale structure and retrogradation of corn starch by partial gelatinization synergizing with epicatechin/epigallocatechin gallate.

Starch retrogradation is of great importance to the quality of starch-based food. This study investigated the effect of partial gelatinization (PG) synergizing with polyphenol (epicatechin, EC; epigallocatechin gallate, EGCG) on the multi-scale structure and short/long-term retrogradation of corn starch (CS). The PG synergizing with EC/EGCG substantially suppressed the short/long-term retrogradation properties of CS.

Covalent conjugation of Inca peanut albumin and polyphenols with different phenolic hydroxyl numbers through laccase catalysis to improve functional properties.

Background: Enzymatic crosslinking is a method that can be used to modify Inca peanut albumin (IPA) using polyphenols, and provides desirable functionalities; however, the effect of polyphenol structures on conjugate properties is unclear. In this study, we selected four polyphenols with different numbers of phenolic hydroxyl groups [para-hydroxybenzoic acid (HBA), protocatechuic acid (PCA), gallic acid (GA), and epigallocatechin gallate (EGCG)] for covalent modification of IPA by enzymatic crosslinking, and explored the structure-function changes of the IPA-polyphenol conjugates.

Results: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) analysis showed that laccase successfully promoted covalent crosslinking of IPA with polyphenols, with the order of degree of conjugation as EGCG > GA > PCA > HBA, the IPA-EGCG conjugate showed the highest polyphenol binding equivalents (98.

Differences in the structural properties of three OSA starches and their effects on the performance of high internal phase Pickering emulsions.

The emulsifying properties of emulsions are significantly influenced by the structural properties of octenyl succinic anhydride (OSA) starch. The purpose of this work was to elucidate the effect of the structure of OSA starch on its performance as an emulsifier to stabilize Pickering high-internal-phase emulsions (HIPEs). The degrees of substitution (DS) of the three OSA starches were 0.

Insight into the improvement in pasting and gel properties of waxy corn starch by critical melting treatments.

To improve the pasting and gel properties of waxy corn starch (WCS), the native starch was modified by critical melting (CM) at the onset temperature (T), peak temperature (T), and conclusion temperature (T) (labeled CMO, CMP, and CMC respectively). CM treatments significantly enhanced the thermal stability of the WCS, as indicated by the increase in the peak gelatinization temperature, pasting temperature, and peak time. In addition, after CMP treatment, the storage modulus, hardness, gumminess, springiness, and chewiness of starch gels significantly increased by 43.

Structural properties of Phoenix oolong tea polysaccharide conjugates and the interfacial stability in nanoemulsions.

Background: Tea polysaccharide conjugate (TPC) is a naturally occurring active substance that is extracted from tea. Owing to its benefits in enhancing human immunity and antioxidant effects, TPC is widely used in culinary products. The binding mode of polysaccharides and proteins in TPC, however, has not been well studied; it may be closely related to their functional properties, especially emulsification.

Ultrasound-assisted reverse micelle extraction and characterization of tea protein from tea residue.

Background: In this study, ultrasonic-assisted reverse micelles were used to extract tea protein from tea residues. First, the extraction conditions of ultrasonic power, ionic strength and pH were optimized by response surface methodology. Then, structural comparison of ultrasonic-assisted reverse micelle extraction of tea protein (UARME) and ultrasonic-assisted alkali extraction (UAAE) were performed using scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and amino acid composition.

Physical modification of maize starch by gelatinizations and cold storage.

The effects of gelatinization at three selected temperatures (DSC characteristic peaks temperature: T, T, and T) and subsequent cold storage (CS) treatment on structural characteristics, pasting, and rheological properties of maize starch (MS) were investigated. The pasting, rheological properties of MS was changed with the increase of gelatinization temperature from T to T, but were not further significantly changed if the gelatinization temperature was higher than T. Pasting and thermal properties analysis suggested that gelatinization at T (TC treatment) significantly increased the gelatinization and pasting temperature of MS.

Activation mechanism of whey protein isolate mediated by free radicals generated in the ascorbic acid/hydrogen peroxide system.

Free radical grafting is a promising method that has been used to modify whey protein isolate (WPI) using polyphenol and provides desirable functionalities, but the reaction mechanism is unclear. This work investigated the grafting mechanism of WPI - (-)-Epigallocatechin-3-gallate (EGCG) through experimental techniques and molecular docking. The results showed that only the ascorbic acid radical anion (Asc) is generated in the Asc/ HO system.

[Intergrating problem-based-learning with flipped classroom teaching in "Principles of chemical engineering" for biological engineering undergraduates].

New engineering program requires training models that conform acceptable time span and principles of engineering education. Considering the program "Principles of chemical engineering" and the limitations of traditional teaching methods, we integrated problem-based learning method and flipped classroom teaching model to reform the course. Through a three-stage systematic teaching design including knowledge learning before class, knowledge internalization in class, and consolidation and expansion after class, we effectively stimulated students' interest and enthusiasm in learning, cultivated students' independent learning ability and engineering thinking, and achieved good teaching effect.

Theoretical Insight into the Interaction between Chloramphenicol and Functional Monomer (Methacrylic Acid) in Molecularly Imprinted Polymers.

Molecular imprinting technology is a promising method for detecting chloramphenicol (CAP), a broad-spectrum antibiotic with potential toxicity to humans, in animal-derived foods. This work aimed to investigate the interactions between the CAP as a template and functional monomers required for synthesizing efficient molecularly imprinted polymers for recognition and isolation of CAP based on density functional theory. The most suitable monomer, methacrylic acid (MAA), was determined based on interaction energies and Gibbs free energy changes.

An Investigation of the Intermolecular Interactions and Recognition Properties of Molecular Imprinted Polymers for Deltamethrin through Computational Strategies.

Deltamethrin (DM) is a toxic pesticide that is nonetheless widely used to control insect pests in agricultural production. Although the number of DM molecularly imprinted polymers (MIPs) is increasing in many scientific applications, the theoretical aspects of the participating intramolecular forces are not fully understood. This paper aims to explore the intermolecular interactions between the template molecule DM and the functional monomer acrylamide (AM) through density functional theory (DFT), analysis of hydrogen nuclear magnetic resonance (H-NMR), Fourier transform infrared spectroscopy (FTIR), and adsorption thermodynamics.

Effects of liquefaction parameters of cellulose in supercritical solvents of methanol, ethanol and acetone on products yield and compositions.

Cellulose extracted from cornstalk was liquefied in supercritical organic solvents at different liquefaction parameters. Different organic solvents (methanol, ethanol and acetone) were used to disintegrate cellulose at different temperatures (240, 260, 280, 300 and 320 °C), reaction time (0, 30, 60, 90 and 120 min) and solvents dosage (0, 80, 120, 160 and 200 mL). The results showed that similar liquefaction characteristics of cellulose were observed in three different solvents.