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To develop recyclable biocatalyst used in Pickering interfacial systems, the pH-responsive monomer [2-(dimethylamine)ethyl methacrylate] (DMAEMA) was grafted onto the maize starch molecule via free radical polymerization. Subsequently, combined with the gelatinization-ethanol precipitation and lipase (Candida rugosa) absorption process, an enzyme-loaded starch nanoparticle with DMAEMA grafting (D-SNP@CRL) was tailor-made, showing a nanometer size and regular sphere. X-ray photoelectron spectroscopy and confocal laser scanning microscopy confirmed a concentration-induced enzyme distribution within D-SNP@CRL, thereof the outside-to-inside enzyme distribution was proved to be optimum in achieving the highest catalytic efficiency. Benefited from the tunable wettability and size of D-SNP@CRL under pH variation, the generated Pickering emulsion could be readily applied as the recyclable microreactors for the n-butanol/vinyl acetate transesterification. This catalysis exhibited both highly catalytic activity and good recyclability, making the enzyme-loaded starch particle a promising green and sustainable biocatalyst in the Pickering interfacial system., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Hydrogel beads composed of oxidized gellan gum (OGG) and resistant starch (RS) were successfully fabricated by ionic cross-linking and used as delivery carriers for resveratrol. Firstly, OGG with different degrees of oxidation were prepared through 2, 2, 6, 6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation, and characterized by Fourier transform infrared spectroscopy and carbon-13 nuclear magnetic resonance to prove that carboxyl groups were successfully introduced into the gellan gum molecules. Molecular weight, thermal stability, zeta potential and gelation temperature of OGG were also investigated. Subsequently, resveratrol was encapsulated into OGG/RS hydrogel beads in the form of resveratrol/β-cyclodextrins inclusion complexes. The addition of RS significantly influenced the morphological structure and swelling capacity of OGG/RS hydrogel beads. The OGG/RS hydrogel beads exhibited a pH-sensitivity and high encapsulation efficiency of resveratrol (84.95 %-90.73 %). Furthermore, the in-vitro release behaviors demonstrated that OGG/RS hydrogel beads showed good stability in simulated gastric fluids and sustained release of resveratrol in simulated intestinal fluids. The obtained results indicate that OGG/RS hydrogel beads show a potential as delivery system for resveratrol in the food industry., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The modified rice starches by octenyl succinic anhydride (OS-RSs) with the same degree of substitution of 0.033 were prepared in aqueous solution using 3% or 20% (w/w) NaOH as a catalyst (OS-RS 3 or OS-RS 20). The results indicated that 20% of NaOH could destroy the structure of starch more seriously and led to more OS groups travelling to interior of starch granules. Furthermore, the storage stability and rheological properties of Pickering emulsions formulated by RS, OS-RS 3 and OS-RS 20 were investigated. Emulsion index of OS-RS 20 were always lower than OS-RS 3 during the storage time, while G', G" and viscosity of O/W Pickering emulsion formulated by OS-RS 20 particles were greater than those of OS-RS 3. OS-RS 3 with more hydrophobic groups in the granule surface could form more compact oil/water layers which contributed greater to the storage stability of Pickering emulsion due to the formation of more compact oil/water layers. However, OS-RS 20 with homogeneous distribution of OS groups in the whole particles resulted in the formation of a tighter droplet network structure that was more resistant to external impacts, which showed OS-RS 20 could improve the shear stability of Pickering emulsion., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Ionic liquids (ILs) utilized for dispersing cellulose have gained increasing attention in recent years, but the number of the reports using ILs for starch is still limited. In this study, 1-butyl-3-methylimidazolium chloride ([BMIM]Cl) and 1-ethyl-3-methlyimidazolium acetate ([EMIM]AC) were used to dispersing corn starch. Dimethyl sulfoxide (DMSO), a traditional organic solvent for starch, was added into [BMIM]Cl, and the mixture of [BMIM]Cl/DMSO was utilized for dispersing corn starch as well. Results showed that the starch granules dispersed in ILs was much smaller than native starch granules, and large starch aggregates were partially formed. Starch granules dispersed in [BMIM]Cl at 100 °C for 60 min remained less crystallinity than native starch granules, while it was disappeared when starch granules were dispersed in [EMIM]AC at 100 °C for 60 min. Homogenous synthesis of fatty-acid starch esters without catalysts in these ILs was also studied. The degree of substitution (DS) value of starch laurate was reached to 0.053, 0.068 and 0.100 in [BMIM]Cl, [EMIM]AC and the mixture of [BMIM]Cl/DMSO, respectively, at the reaction conditions of lauric acid/AGU molar ratio 1:5, temperature 120 °C at a reaction time of 3 h., (Copyright © 2012 Elsevier Ltd. All rights reserved.)