There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Research on and the application of polyphenols, have recently attracted great interest in the functional foods, nutraceutical and pharmaceutical industries, due to their potential health benefits to humans. However, the effectiveness of polyphenols depends on preserving the stability, bioactivity and bioavailability of the active ingredients. The unpleasant taste of most phenolic compounds also limits their application. The utilization of encapsulated polyphenols, instead of free compounds, can effectively alleviate these deficiencies. The technologies of encapsulation of polyphenols, including spray drying, coacervation, liposome entrapment, inclusion complexation, cocrystallization, nanoencapsulation, freeze drying, yeast encapsulation and emulsion, are discussed in this review. Current research, developments and trends are also discussed.

Encapsulation of polyphenols – a review

Potential applications of enzymes immobilized on/in nano materials: A review

Chitosan as a bioactive polymer: Processing, properties and applications.

Two-step method for encapsulation of oregano essential oil in chitosan nanoparticles: Preparation, characterization and in vitro release study

This work investigated the polyanion-initiated gelation process in fabricating chitosan-tripolyphosphate (CS-TPP) nanoparticles intended to be used as carriers for delivering tea catechins. The results demonstrated that the particle size and surface charge of CS-TPP nanoparticles could be controlled by fabrication conditions. For preparation of CS-TPP nanoparticles loaded with tea catechins, the effects of modulating conditions including contact time between CS and tea catechins, CS molecular mass, CS concentration, CS-TPP mass ratio, initial pH value of CS solution, and concentration of tea catechins on encapsulation efficiency and the release profile of tea catechins in vitro were examined systematically. The study found that the encapsulation efficiency of tea catechins in CS-TPP nanoparticles ranged from 24 to 53%. In addition, FT-IR analysis showed that the covalent bonding and hydrogen bonding between tea catechins and CS occurred during the formation of CS-TPP nanoparticles loaded with tea catechins. Furthermore, studies on the release profile of tea catechins in vitro demonstrated that the controlled release of tea catechins using CS-TPP nanoparticles was achievable.

Optimization of Fabrication Parameters To Produce Chitosan−Tripolyphosphate Nanoparticles for Delivery of Tea Catechins

Effect of ultrasound on different quality parameters of apple juice

A new, simple, and effective method to graft gallic acid (GA) onto chitosan (CS) in aqueous solution in the presence of carbodiimide and hydroxybenzotriazole was developed. The grafting amount of GA reached as much as 209.9 mg/g of copolymer, which appears as the highest one among the reported literature, and the grafting degree of GA to CS was adjustable with modulation of the mass ratio of GA to CS. The covalent insertion of GA onto the polymeric backbones was confirmed by UV–vis and 1H NMR analyses. Grafting endowed the resulting copolymer GA-grafted-CS (GA-g-CS) with both the advantages of CS and GA. The antioxidant capacity of GA-g-CS was much higher than that of the plain CS examined by assays of DPPH, superoxide, and ABTS radicals scavenging activities, reducing power, chelating power, inhibition of lipid peroxidation, ferric reducing antioxidant potential, and β-carotene-linoleic acid assays. Particularly, GA-g-CS showed significantly higher antioxidant activity than GA in β-carotene-linoleic acid...

Grafting of Gallic Acid onto Chitosan Enhances Antioxidant Activities and Alters Rheological Properties of the Copolymer

A novel and efficient immobilization of β-d-galactosidase from Aspergillus oryzae has been developed by using magnetic Fe3O4–chitosan (Fe3O4–CS) nanoparticles as support. The magnetic Fe3O4–CS nanoparticles were prepared by electrostatic adsorption of chitosan onto the surface of Fe3O4 nanoparticles made through co-precipitation of Fe2+ and Fe3+. The resultant material was characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry and thermogravimetric analysis. β-d-Galactosidase was covalently immobilized onto the nanocomposites using glutaraldehyde as activating agent. The immobilization process was optimized by examining immobilized time, cross-linking time, enzyme concentration, glutaraldehyde concentration, the initial pH values of glutaraldehyde and the enzyme solution. As a result, the immobilized enzyme presented a higher storage, pH and thermal stability than the soluble enzyme. Galactooligosaccharide was formed with lactose as substrate by using the immobilized enzyme as biocatalyst, and a maximum yield of 15.5% (w/v) was achieved when about 50% lactose was hydrolyzed. Hence, the magnetic Fe3O4–chitosan nanoparticles are proved to be an effective support for the immobilization of β-d-galactosidase.

Bing Hu

Papers

Optimization of Fabrication Parameters To Produce Chitosan−Tripolyphosphate Nanoparticles for Delivery of Tea Catechins

Effect of ultrasound on different quality parameters of apple juice

Grafting of Gallic Acid onto Chitosan Enhances Antioxidant Activities and Alters Rheological Properties of the Copolymer

Novel and efficient method for immobilization and stabilization of β-d-galactosidase by covalent attachment onto magnetic Fe3O4–chitosan nanoparticles

Antioxidant activities of polysaccharides from Hyriopsis cumingii