Zhang Shanshan, Xin Minghang, Wang Zhiyu, Dong Xiaolan, Yang Chenhe, Liu Hongcheng, Fan Hongxiu, Liu Tingting, Wang Dawei
School of Food Science and Engineering, Jilin Agricultural University, Changchun 130118, China.
Engineering Research Center of Grain Deep-Processing and High-Effeciency Utilization of Jilin Province, Changchun 130118, China.
Foods. 2023 Nov 10;12(22):4087. doi: 10.3390/foods12224087.
In this study, Tiger nut ( L.) oil-based oleogels were prepared using the emulsion template method with whey protein (WPI; 0.5-2.5% (/) and Xanthan gum (XG; 0.1-0.5% (/). The microstructure of the oleogels obtained from the high internal phase emulsion (HIPE) and an emulsion after further shearing were observed using an optical microscope and laser confocal microscopy. A series of rheological tests were conducted to evaluate the effect of WPI and XG concentrations on the strength of the emulsion and oleogel. The texture, oil holding capacity, and oxidative stability of oleogels were characterized. The results showed that XG alone could not form oleogel, while the concentration of WPI had more effect than XG. When WPI was at a fixed concentration, the viscoelasticity of HIPE increased with the addition of XG. This was due to the complexation of WPI and XG, forming a stable gel network between the tight emulsion droplets and thus giving it a higher viscoelasticity. With an increase in WPI concentration, the stability and viscoelasticity of the emulsion were increased, and the oil-holding capacity and gel strength of the oleogels were enhanced. Moreover, the addition of XG could significantly enhance the stability and viscoelasticity of the emulsion ( < 0.05), and an increase in the concentration had a positive effect on it. The oleogels showed high gel strength (G' > 15,000 Pa) and good thixotropic recovery when the XG concentration was higher than 0.3% (/). WPI (2.0%) and XG (>0.3%) could be used to obtain HIPE with good physicochemical and viscoelastic properties, which in turn lead to oleogels with minimal oil loss, viscoelastic and thixotropic recovery, and temperature stability. Compared with tiger nut oil-based oleogel, tiger nut oil contained more polyunsaturated fatty acids, which were more easily decomposed through oxidation during storage and had lower oxidation stability. This study provides a reference for the preparation of oleogels from food-approved polymers and provides additional theoretical support for their potential application as solid fat substitutes.
在本研究中，采用乳液模板法，以乳清蛋白（WPI；0.5 - 2.5%（/））和黄原胶（XG；0.1 - 0.5%（/））制备了油莎豆（L.）油基油凝胶。使用光学显微镜和激光共聚焦显微镜观察了从高内相乳液（HIPE）和进一步剪切后的乳液中获得的油凝胶的微观结构。进行了一系列流变学测试，以评估WPI和XG浓度对乳液和油凝胶强度的影响。对油凝胶的质地、持油能力和氧化稳定性进行了表征。结果表明，单独的XG不能形成油凝胶，而WPI的浓度比XG的影响更大。当WPI浓度固定时，HIPE的粘弹性随着XG的添加而增加。这是由于WPI和XG的络合作用，在紧密的乳液滴之间形成了稳定的凝胶网络，从而使其具有更高的粘弹性。随着WPI浓度的增加，乳液的稳定性和粘弹性增加，油凝胶的持油能力和凝胶强度增强。此外，XG的添加可以显著提高乳液的稳定性和粘弹性（<0.05），且浓度增加对其有积极影响。当XG浓度高于0.3%（/）时，油凝胶表现出高凝胶强度（G' > 15,000 Pa）和良好的触变恢复性。WPI（2.0%）和XG（>0.3%）可用于获得具有良好物理化学和粘弹性的HIPE，进而得到油损失最小、具有粘弹性和触变恢复性以及温度稳定性的油凝胶。与油莎豆油基油凝胶相比，油莎豆油含有更多的多不饱和脂肪酸，在储存过程中更容易通过氧化分解，氧化稳定性较低。本研究为从食品级聚合物制备油凝胶提供了参考，并为其作为固体脂肪替代品的潜在应用提供了额外的理论支持。
