Leon Alicia M, Medina Wenceslao T, Park Dong J, Aguilera José M
1 Department of Chemical and Bioprocesses Engineering, Pontificia Universidad Católica de Chile, Santiago, Chile.
2 Department of Agroindustries, Faculty of Agrarian Sciences, Universidad Nacional del Altiplano de Puno, Puno, Peru.
Food Sci Technol Int. 2018 Jul;24(5):414-423. doi: 10.1177/1082013218762210. Epub 2018 Feb 28.
Designing soft, palatable and nutritious texture-modified foods for the elderly is a challenge for food technologists. The aim of this work was to produce and characterize emulsion-gelled microparticles (EGM) made from whey protein isolate (WPI) and sodium alginate (NaAlg) that may be used to modify the rheology of liquid foods and as carriers of lipids and lipophilic nutrients and bioactives. Olive oil microdroplets became embedded in the WPI/NaAlg gel matrix in the form of an emulsion produced by ultrasound (US) or high-speed blending (HSB). Oil microdroplets were obtained by US and HSB, with an average equivalent diameter varying between 2.0-3.2 µm and 4.5-6.7 µm, respectively. Oil incorporation increased compression stress of bulk emulsion gels at small deformations compared to the no-oil microgel, but this effect was reversed at high strains. EGM were prepared by shear-induced size reduction. Rheological tests at 20 ℃ and 40 ℃ showed that US-EGM and HSB-EGM exhibited a predominant elastic behavior, with G' > G″ throughout the frequency range. However, when HSB-EGM were heated at 60 ℃ their rheological behavior changed to a more fluid-like condition, but not that of US-EGM. Consequently, EGM have the properties needed to improve food texture for people with masticatory/swallowing dysfunctions or needing special nutrition.
为老年人设计柔软、可口且营养丰富的质构改良食品，对食品技术专家来说是一项挑战。这项工作的目的是制备并表征由乳清蛋白分离物（WPI）和海藻酸钠（NaAlg）制成的乳液凝胶微粒（EGM），其可用于改变液态食品的流变学性质，并作为脂质、亲脂性营养物质和生物活性物质的载体。橄榄油微滴以通过超声（US）或高速搅拌（HSB）产生的乳液形式嵌入WPI/NaAlg凝胶基质中。通过US和HSB获得油微滴，其平均等效直径分别在2.0 - 3.2 µm和4.5 - 6.7 µm之间变化。与无油微凝胶相比，在小变形时油的加入增加了本体乳液凝胶的压缩应力，但在高应变时这种效果相反。EGM通过剪切诱导的尺寸减小来制备。在20℃和40℃下的流变学测试表明，US - EGM和HSB - EGM在整个频率范围内均表现出主要的弹性行为，G' > G″。然而，当HSB - EGM在60℃加热时，其流变学行为变为更类似流体的状态，但US - EGM并非如此。因此，EGM具有改善咀嚼/吞咽功能障碍者或需要特殊营养者食品质地所需的特性。
