Maidannyk V A, Lim A S L, Auty M A E, Roos Y H
Food Chemistry & Technology Department, Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.; School of Food and Nutritional Sciences, University College Cork, Cork, Ireland.
Food Chemistry & Technology Department, Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland.
Food Res Int. 2019 Feb;116:1212-1222. doi: 10.1016/j.foodres.2018.10.008. Epub 2018 Oct 3.
Encapsulant systems are gaining wide practical interest due to their functional and nutritional properties. This paper was focusing on understanding structural relaxations in that systems near glass transition temperature. Freeze-dried trehalose-whey protein isolate-sunflower oil systems with various ratios of the last were used as a carbohydrate-protein-lipid food model. The Guggenheim-Anderson-de Boer (GAB) water sorption relationship was used as a tool to model water sorption isotherms. The glass transition temperature was obtained by differential scanning calorimetry (DSC). Structural α-relaxation temperatures were measured by dynamical mechanical analyses (DMA), dielectric analysis (DEA) and combined to cover a broad range for strength assessment. The microstructure was characterized by optical light microscopy, confocal laser scanning microscopy and scanning electron microscopy. The C and C constants for Williams-Landel-Ferry (WLF) equation and structural strength parameter were calculated for each system. The effect of sunflower oil and water contents on strength of carbohydrate-protein system was analyzed. Strength shows decreasing with increasing of lipid concentration in the mixtures and more complex dependence on the water content in a system.
由于其功能和营养特性，密封剂体系正受到广泛的实际关注。本文着重于了解该体系在玻璃化转变温度附近的结构弛豫。将具有不同比例葵花籽油的冻干海藻糖-乳清蛋白分离物-葵花籽油体系用作碳水化合物-蛋白质-脂质食品模型。采用 Guggenheim-Anderson-de Boer（GAB）水吸附关系来模拟水吸附等温线。通过差示扫描量热法（DSC）获得玻璃化转变温度。通过动态力学分析（DMA）、介电分析（DEA）测量结构α弛豫温度，并将两者结合以覆盖较宽范围进行强度评估。通过光学显微镜、共聚焦激光扫描显微镜和扫描电子显微镜对微观结构进行表征。计算每个体系的 Williams-Landel-Ferry（WLF）方程的 C 和 C 常数以及结构强度参数。分析了葵花籽油和水含量对碳水化合物-蛋白质体系强度的影响。强度随混合物中脂质浓度的增加而降低，并且对体系中的水含量有更复杂的依赖性。
