Tweed Research Center, Onyx Développement SAS, Groupe Nutriset, 640 Chemin du Château, 76770 Malaunay, France; Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 91300 Massy, France.
Université Paris-Saclay, INRAE, AgroParisTech, UMR SayFood, 91300 Massy, France.
Food Res Int. 2020 Nov;137:109362. doi: 10.1016/j.foodres.2020.109362. Epub 2020 Jun 9.
Peanut proteins are mostly composed of arachins and conarachins, globular proteins that can form gels under thermal denaturation or enzymatic treatment. We explored here how ionic strength (0.5 M or 0.8 M) and gelation process (a thermal treatment preceded or not by an enzymatic pre-treatment) could affect peanut protein gel properties. Gel formation and final properties were characterized by rheology, and gel structure was observed by confocal microscopy. We found that the ionic strength imposed during protein extraction determines the arachins/conarachins ratio, and that conarachins-rich samples give stronger gels, which is attributed to their higher content in free thiol groups and lysine residues. The gel storage modulus exhibited a power-law dependence with the protein concentration, which exponent depended on the gelation process. Rheological results, together with confocal microscopy imaging, showed that an enzymatic pre-treatment resulted in denser structures than when a simple thermal treatment was applied.
花生蛋白主要由 arachins 和 conarachins 组成，这两种球蛋白在热变性或酶处理下可形成凝胶。本研究探讨了离子强度（0.5 M 或 0.8 M）和凝胶形成过程（是否先进行酶预处理再进行热处理）如何影响花生蛋白凝胶特性。通过流变学特性来表征凝胶的形成和最终性能，并通过共聚焦显微镜观察凝胶结构。结果发现，在蛋白质提取过程中施加的离子强度决定了 arachins/conarachins 的比例，并且富含 conarachins 的样品形成的凝胶更强，这归因于其较高含量的游离巯基和赖氨酸残基。凝胶储能模量与蛋白质浓度呈幂律关系，其指数取决于凝胶形成过程。流变学结果结合共聚焦显微镜成像表明，与简单的热处理相比，酶预处理会导致更密集的结构。
