Effects of various emulsification methods on the oxidation of methyl linoleate.

The effects of mechanical stress during emulsification on the oxidation of methyl linoleate were investigated by four methods (high-pressure homogenization, high-speed stirring, ultrasonic homogenization, and membrane emulsification). The oxidation rates and induction periods were almost constant, regardless of the emulsification method, except for membrane emulsification, by which the induction period was prolonged when a cellulose acetate membrane was used.

Structural and mechanistic insights into starch microgel/anthocyanin complex assembly and controlled release performance.

We report a self-assembly method for the fabrication of multilayer-starch-based microgels used for anthocyanin encapsulation. Alcohol-heating treatment and ionization reactions were employed to reduce the crystallinity of starch and introduce ionic groups on the molecule to further cross-link it with sodium trimetaphosphate and produce a starch microgel. The molecular interactions between the starch and the anthocyanins facilitated the anthocyanin encapsulation and the starch-microgel/anthocyanin complexes with one, two, and three self-assembled layers were obtained. The Lay-1 microgel exhibited an encapsulation efficiency of 50.1% when the anthocyanin concentration, cross-linking starch concentration, contact time, and temperature were 0.25 mg/mL, 1.5 mg/mL, 3 h, and 40 °C, respectively. An increase in the number of layers resulted in a more compact microgel structure with the zeta potential presenting variations upon structural changes. Furthermore, the encapsulated anthocyanins presented a slow release from Lay-1, while the multilayered microgels (Lay-2 and Lay-3) displayed outstanding encapsulation stability. This study gives an insight on the encapsulation and release of anthocyanins by starch microgels, and provides a novel strategy for the design of starch-based encapsulation materials presenting great stability.

Emerging starch composite nanofibrous films for food packaging: Facile construction, hydrophobic property, and antibacterial activity enhancement.

Polymers synthesized from green resources have many advantages in food packaging and hence their development is very important. Herein, starch/polyvinyl alcohol (PVA) nanofibrous composite films were fabricated by electrospinning technology. Steam-induced cross-linking reaction with glutaraldehyde (GTA) and silver sodium zirconium phosphate (Ag-ZrP) was employed to improve the hydrophobic and antibacterial properties of the constructed nanofibrous films, respectively. The effects of starch/PVA ratio on the micro-morphology and mechanical properties of the binary composite film were investigated. The composite film showed optimal uniformity, bead-free electrospun nanofibers, with enhanced mechanical strength for the 60/40 (v/v) starch/PVA composite. Moreover, the crystallinity of PVA was reduced during the electrospinning process, whereas the introduction of PVA strengthened the hydrogen interactions and improved the thermal stability of the composite films. After the cross-linking with GTA, the starch/PVA films became more hydrophobic. Furthermore, the starch/PVA films embedded with Ag-ZrP had outstanding antibacterial property against both Gram-negative and Gram-positive bacteria. This work demonstrated the potential prospects of electrospun starch nanofibrous films in the food packaging field.

Application of an optosensing chip based on molecularly imprinted polymer coated quantum dots for the highly selective and sensitive determination of sesamol in sesame oils.

A novel optosensing chip was constructed by anchoring the fluorescence sensing material layer based on molecularly imprinted polymer (MIP) coated CdSe/ZnS quantum dots (QDs) on a chip for highly selective and sensitive optosensing of sesamol in sesame oil. Many factors that affected the performance of the optosensing chip based on MIP-coated QDs are discussed. Under optimized conditions, the relative fluorescence intensity of the optosensing chip decreased linearly (r(2) > 0.99) with increasing sesamol concentration in the range from 2.4 × 10(-6) to 1.2 × 10(-3) mol L(-1) with a detection limit of 7.2 × 10(-8) mol L(-1). The relative standard deviation for five replicate detections of 4.8 × 10(-4) mol L(-1) sesamol was 2.2%. Recoveries of 94.8-102.3% were achieved by direct detection when the optosensing chip was used for the selective detection of sesamol in sesame oil. Practically, the optosensing approach showed high sensitivity, good selectivity, and excellent reproducibility for the detection of sesamol in real oil samples.