A comprehensive review on polarity,partitioning, and interactions of phenolic antioxidants at oil–water interface of food emulsions

There has been a growing interest in developing effective strategies to inhibit lipid oxidation in emulsified food products by utilization of natural phenolic antioxidants owing to their growing popularity over the past decades. However, due to the complexity of emulsified systems, the inhibition mechanism of phenolic antioxidants against lipid oxidation is rather complicated and not yet fully understood. In order to highlight the importance of polarity of phenolic antioxidants in emulsified systems according to the polar paradox, this review covers the recent progress on chemical, enzymatic, and chemoenzymatic lipophilization techniques used to modify the polarity of antioxidants. The partitioning behavior of phenolic antioxidants at the oil–water interface, which can be influenced by the presence of synthetic surfactants and/or antioxidant emulsifiers (e.g., polysaccharides, proteins, and phospholipids), is discussed. In addition, the emerging phenolic antioxidants among phenolic acids, flavonoids, tocopherols, and stilbenes applied in food emulsions are elaborated. As well, the interactions of polar–nonpolar antioxidants are stressed as a promising strategy to induce synergistic interactions at oil–water interface for improved oxidative stability of emulsions.     

纳米CaCO_3/PVA复合材料的制备与表征

以亲油化度为考察指标,运用单因子实验和正交实验得到纳米碳酸钙表面改性的最佳条件为:改性剂的摩尔比(硬脂酸:月硅酸钠)1:1,改性剂总量0.75 g,改性时间1.5 h,改性温度80℃.在优化条件下,改性后的纳米碳酸钙的亲油化度达N55.67%.将改性的纳米碳酸钙与聚乙烯醇(PVA)相溶,制得纳米CaCO3/PVA复合材料.同时用红外光谱及TEM等测试手段,对改性前后CaCO3及CaCO3/PVA复合材料的结构及微观形貌进行了表征.结果表明,纳米CaCO3在PVA中分散性良好,粒径为30 nm左右.     

Preparation and properties of poly(lactic acid)/lipophilized graphene oxide nanohybrids

Poly(lactic acid) (PLA)/lipophilized graphene oxide (LGO) nanohybrids were prepared using a solution blending method. Graphene oxide (GO) was synthesized using a modified Hummers method and then lipophilized by functionalization with alkylamines such as octylamine, dodecylamine or octadecylamine (ODA). PLA/GO nanohybrids were also prepared for comparison. Among the LGOs, ODA‐GO was chosen to produce the PLA/LGO nanohybrids because ODA‐GO exhibited obvious intercalation behavior and the best dispersibility in chloroform. The properties of the PLA/GO and PLA/LGO nanohybrids were investigated using scanning electron microscopy, wide‐angle X‐ray diffraction, differential scanning calorimetry, thermogravimetric analysis, a universal testing machine, chemical resistance measurements and hydrolytic degradability analysis. The hydrophobic ODA‐GO was dispersed on the nanoscale within the PLA matrix and the resulting nanohybrids showed significantly higher chemical resistance and reduced hydrolytic degradation. © 2017 Society of Chemical Industry