School of Food Science and Bioengineering, Xihua University, Chengdu 610039, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Chongqing 400715, China.
School of Food Science and Bioengineering, Xihua University, Chengdu 610039, China; Chongqing Key Laboratory of Speciality Food Co-Built by Sichuan and Chongqing, Chongqing 400715, China.
Food Res Int. 2023 Jul;169:112858. doi: 10.1016/j.foodres.2023.112858. Epub 2023 Apr 20.
Alkaline-extracted walnut protein isolates showed relatively poor solubility and emulsifying properties in many previous studies. However, whether they can be used as potential emulsifiers to stabilize high internal phase emulsions (HIPEs) remains unknown. Herein, walnut protein isolates were prepared by alkaline extraction from walnut kernels with or without pellicles (named PAWPI and AWPI, respectively). PAWPI conjugated with pellicle polyphenols showed improved solubility and higher antioxidant capacity than AWPI. HIPEs were fabricated via a one-step method using AWPI or PAWPI as the sole protein emulsifier. HIPEs (oil fraction of 0.8, with 0.1% β-carotene) could be stabilized by PAWPI at a relatively low concentration of 0.2% (w/v), while at least 1% (w/v) AWPI was required to effectively stabilize HIPEs. HIPEs stabilized by PAWPI had smaller oil droplet sizes than those stabilized by AWPI. Rheological analysis indicated that PAWPI-stabilized HIPEs showed higher viscosity and better viscoelasticity than AWPI-stabilized HIPEs. Large-amplitude oscillation shearing analysis suggested that PAWPI-stabilized HIPEs were stiffer but more brittle than AWPI-stabilized HIPEs. Moreover, both PAWPI- and AWPI-stabilized HIPEs exhibited good storage stability and were relatively stable against heat treatment and ionic strength. PAWPI-stabilized HIPEs showed a higher protective capacity for encapsulated β-carotene than AWPI-stabilized HIPEs. In addition, PAWPI-stabilized HIPEs showed good 3D printability and could be used as a promising edible ink.
在之前的许多研究中，碱性提取的核桃蛋白分离物的溶解性和乳化性能都相对较差。然而，它们是否可以用作潜在的乳化剂来稳定高内相乳液（HIPE）尚不清楚。在此，采用带或不带种皮（分别命名为 PAWPI 和 AWPI）的核桃仁，通过碱性提取法制备了核桃蛋白分离物。与 AWPI 相比，PAWPI 与种皮多酚结合后，溶解性提高，抗氧化能力增强。通过一步法制备 HIPE，使用 AWPI 或 PAWPI 作为唯一的蛋白质乳化剂。HIPE（油相分数为 0.8，含 0.1%β-胡萝卜素）可在相对较低的 0.2%（w/v）浓度下用 PAWPI 稳定，而有效稳定 HIPE 则需要至少 1%（w/v）的 AWPI。PAWPI 稳定的 HIPE 的油滴粒径小于 AWPI 稳定的 HIPE。流变分析表明，与 AWPI 稳定的 HIPE 相比，PAWPI 稳定的 HIPE 具有更高的粘度和更好的粘弹性。大振幅振荡剪切分析表明，与 AWPI 稳定的 HIPE 相比，PAWPI 稳定的 HIPE 更硬但更脆。此外，PAWPI 和 AWPI 稳定的 HIPE 均表现出良好的储存稳定性，对热处理和离子强度相对稳定。与 AWPI 稳定的 HIPE 相比，PAWPI 稳定的 HIPE 对包埋的β-胡萝卜素具有更高的保护能力。此外，PAWPI 稳定的 HIPE 具有良好的 3D 打印性能，可用作有前途的食用墨水。
