School of Agriculture and Food Sciences, The University of Queensland, St. Lucia, Queensland 4072, Australia.
J Texture Stud. 2018 Jun;49(3):274-285. doi: 10.1111/jtxs.12307. Epub 2017 Nov 13.
Effects of adding four functional ingredients: inulin, pectin, galacto-oligosaccharides (GOS), and beta glucan on physical, rheology, tribology, and sensory characteristics of skim (0.1% fat) stirred yoghurt were studied. Three levels of each ingredient were chosen: inulin (7, 8, and 9%), pectin (0.2, 0.25, and 0.3%), GOS (9.1, 11.3, and 13.6%), and beta glucan (0.1, 0.2, and 0.3%). Among the investigated ingredients, inulin and GOS appeared to be preferable choices due to their ability to both reduce syneresis and slightly increase sample lubrication while maintaining texture, rheology, and sensory characteristics of skim yoghurt. Pectin and beta glucan, conversely, increased viscosity and gel strength, slightly increased sample lubrication for the skim yoghurt but created large particles (i.e., greater than 100 μm) in the product body. This led to the increase in lumpiness and residual coating while reducing smoothness and creaminess of the sample. The observed tribology behaviors of the stirred yoghurts were similar to the previous study of pot-set yoghurt whose friction curves comprised four friction zones (Nguyen, Kravchuk, Bhandari, and Prakash). The sensory characteristics of six selected samples for various texture and mouthfeel attributes obtained from a trained panel were in agreement with particle size, rheology, and tribology characteristics of the yoghurt samples.
With the increasing demand for low fat and functional food, there is a need to understand the impact of adding functional ingredients in low fat yoghurt to satisfy consumers' requirements. This study investigates the effects of these functional ingredients at different dosages on physical, rheology, tribology, and sensory characteristics of skim (0.1% fat) stirred yoghurt. The results from this study may guide use of functional ingredients in yoghurt production.
研究了四种功能性成分（菊粉、果胶、半乳糖低聚糖（GOS）和β葡聚糖）对脱脂（0.1%脂肪）搅拌酸奶物理性质、流变学、摩擦学和感官特性的影响。选择了每种成分的三个水平：菊粉（7、8 和 9%）、果胶（0.2、0.25 和 0.3%）、GOS（9.1、11.3 和 13.6%）和β葡聚糖（0.1、0.2 和 0.3%）。在所研究的成分中，菊粉和 GOS 似乎是更好的选择，因为它们既能减少离浆，又能稍微增加样品的润滑性，同时保持脱脂酸奶的质地、流变学和感官特性。相比之下，果胶和β葡聚糖增加了粘度和凝胶强度，稍微增加了脱脂酸奶的样品润滑性，但在产品体内形成了较大的颗粒（即大于 100μm）。这导致了块状物的增加和残留涂层的减少，同时降低了样品的光滑度和奶油感。搅拌酸奶的观察到的摩擦学行为与之前的 pot-set 酸奶研究相似，其摩擦曲线包括四个摩擦区（Nguyen、Kravchuk、Bhandari 和 Prakash）。从训练有素的小组获得的六种不同质地和口感属性的样品的感官特征与酸奶样品的粒径、流变学和摩擦学特征一致。
随着对低脂和功能性食品需求的增加，需要了解在低脂酸奶中添加功能性成分对满足消费者需求的影响。本研究调查了这些功能性成分在不同剂量下对脱脂（0.1%脂肪）搅拌酸奶物理性质、流变学、摩擦学和感官特性的影响。本研究的结果可以指导功能性成分在酸奶生产中的使用。
