Tuning the rheological and tribological properties to simulate oral processing of novel high internal phase oleogel-in-water emulsions
Tuning the rheological and tribological properties to simulate oral processing of novel high internal phase oleogel-in-water emulsions
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DOI：
10.1016/j.foodhyd.2022.107757
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发表时间：
2022-04
影响因子：
10.7
通讯作者：
Yanhui Zhang;Yichuan Wang;Ruo-Jie Zhang;Jing-wen Yu;Yanxiang Gao;Like Mao
中科院分区：
文献类型：
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作者：
Yanhui Zhang;Yichuan Wang;Ruo-Jie Zhang;Jing-wen Yu;Yanxiang Gao;Like Mao
本研究报道了一种新型的由油凝胶和蛋白质稳定的水包油高内相乳液（HIPES）。研究了乙基纤维素（EC，oleogelator）和油分对乳液微观结构、稳定性、线性/非线性流变性能和摩擦学性能的影响。CLSM和Cryo-SEM观察结果表明，油和EC含量的增加有助于液滴的尺寸变小（从13.3 μ m到8.17 μm）和更紧密的堆积。EC分布在油滴内部，并倾向于向界面移动。油相的甘氨酰化使得乳液具有更高的抗离心物理稳定性。与中等内相乳液（60重量%油）相比，HIPE（75重量%油）对剪切更敏感。小振幅振荡剪切分析表明，列入EC导致更硬（更高的模量），更强（更高的临界应力），更脆（更低的临界应变）的乳液的属性。大振幅振荡剪切实验表明，含油量高的乳液表现出较弱的应变超调行为，而含EC的HIPE表现出应变变稀特性。Lissajous-Bowditch曲线进一步揭示了HIPE对大变形的敏感性。没有EC的乳液表现出更高的结构弹性，更耐大变形，而与EC的乳液表现出更高的非线性响应。摩擦学试验表明，EC的加入有助于提高乳液在混合区和流体动力润滑区的摩擦系数。所得信息有助于了解浓缩乳剂的口服行为和功能性食品的设计。
The current study reported novel oil-in-water high internal phase emulsions (HIPEs) stabilized by oleogel and a protein. Effects of ethyl cellulose (EC, oleogelator) and oil fraction on the microstructures, stability, linear/non-linear rheological, and tribological properties of the emulsions were investigated. CLSM and Cryo-SEM observations indicated that the increase of oil and EC content contributed to a smaller size (from 13.3 to 8.17 μm) and tighter packing of the droplets. EC was distributed inside the oil droplets and tended to move towards the interface. Gelation of the oil phase allowed the emulsions with higher physical stability against centrifugation. Compared to medium internal phase emulsions (60 wt% oil), HIPEs (75 wt% oil) were more sensitive to shearing. Small amplitude oscillation shearing analysis revealed that the inclusion of EC led to stiffer (higher moduli), stronger (higher critical stress), and more brittle (lower critical strain) properties of the emulsions. Large amplitude oscillation shearing tests showed that the emulsions with higher oil content presented weaker strain overshoot behaviors, while HIPEs with EC showed strain thinning characteristics. Lissajous-Bowditch curves further revealed that HIPEs were more sensitive to large deformation. Emulsions without EC showed higher structural elasticity and were more resistant to large deformations, while emulsions with EC exhibited higher nonlinear responses. Tribology tests suggested that the addition of EC contributed to higher friction coefficients of emulsions in mixed and hydrodynamic lubrication regions. The information obtained would be helpful in understanding the oral behavior of concentrated emulsions and designing functional food.