乳铁蛋白-乳清分离蛋白乳状液微聚集体构建与酶交联对其流变学特性的影响

以乳清分离蛋白（whey protein isolate,WPI）与乳铁蛋白（lactoferrin,LF）乳状液形成微聚集体与转谷氨酰胺酶酶促交联微聚集体,以期提高体系流变特性。通过微射流分别制备WPI和LF乳状液,二者混合后,乳状液微滴之间发生异型聚集效应,通过转谷氨酰胺酶交联结合形成具有特定三维空间网络结构的微聚集体。研究结果表明：WPI与LF乳状液发生异型聚集,最大程度的聚集和最高物理稳定性体系发生在50% LF-50% WPI微滴形成的微聚集体。异型聚集效应改变了乳状液的流变特性,与单一WPI和LF乳状液相比,50% LF-50% WPI微聚集体流变学特性黏度值分别为单一乳状液的3.72?倍和2.2?倍,通过转谷氨酰胺酶交联,乳状液微聚集体的黏度值为原来的11.4?倍。因此,基于异型聚集效应结合酶促交联,可提高食品体系的流变特性,为开发食品脂质替代物提供了一定的理论支持。     

Dissipation behavior of five organophosphorus pesticides in kumquat sample during honeyed kumquat candied fruit processing

The fate of five organophosphorus pesticides (dimethoate, chlorpyrifos, malathion, methidathion and triazophos) in kumquat samples during honeyed kumquat candied fruit processing was assessed. Residues were determined by gas chromatograph with a flame photometric detector (GC-FPD) after each procedure including washing, grinding, juice & seeds removing, hardening, blanching, sugar-immersing, boiling, drying and mixing with granulated sugar. Results showed that no methidathion was detected after boiling. The drying step increased dimethoate, malathion, and triazophos by 13%, 15% and 6.3%, respectively, only reduced 11% of chlorpyrifos. Processing factors (PFs) for the individual procedures were generally <1 except the PFs of dimethoate, malathion and triazophos after drying. The PFs of the overall process for dimethoate, chlorpyrifos, malathion, methidathion and triazophos were 0.02, 0.30, 0.09, <0.06 and 0.15, indicating the whole process can significantly reduce five pesticide residues in honeyed kumquat candied fruit.