College of Food Science, Southwest University, Chongqing 400715, China.
Chongqing Sericulture Science and Technology Research Institute, Chongqing 400700, China.
Int J Biol Macromol. 2022 Sep 1;216:272-281. doi: 10.1016/j.ijbiomac.2022.07.005. Epub 2022 Jul 5.
In this study, the pineapple peel cellulose nanofibrils (PCNFs) were facilely isolated by a dilute alkali assisted ball milling technique, then used to adjust the stabilization of low internal phase oil-in-water emulsions (oil phase 30 vol%) stabilized by gelatin (GLT, 1 wt%). The ball milling with the aid of NaOH solution (3 wt%) efficiently promoted the purification and defibrillation of cellulose through a one-pot approach, showing an average length of 0.77 μm and crystallinity index of 43.5 %. With the increase of PCNFs concentration (0-1.0 wt%), the emulsions showed an increased droplet size (51.2-76.9 μm) and a gradually decreasing bottom water layer. The apparent viscosity, storage modulus (G') and loss modulus (G") of emulsions evidently increased with increasing PCNFs addition. The result of confocal laser scanning microscopy (CLSM) confirmed the stabilization mechanism of GLT/PCNFs emulsions, involving the interface adsorption by GLT and the formation of viscoelastic network structure by PCNFs. The environmental stabilities of GLT emulsion could be improved by introducing PCNFs, except for at high ionic strength (> 100 mM). Notably, PCNFs effectively avoided the adverse effect of GLT isoelectric point (pH 5) on the stability of emulsion.
在这项研究中，通过稀碱辅助球磨技术简便地分离菠萝皮纤维素纳米纤维（PCNFs），然后用于调节明胶（GLT，1wt%）稳定的低内相比水包油乳液（油相 30vol%）的稳定性。在 3wt%NaOH 溶液的辅助下进行球磨，通过一锅法有效地促进了纤维素的纯化和纤维化，得到的纤维素纳米纤维平均长度为 0.77μm，结晶度指数为 43.5%。随着 PCNFs 浓度（0-1.0wt%）的增加，乳液的液滴尺寸（51.2-76.9μm）逐渐增大，底部水层逐渐减少。乳液的表观黏度、储能模量（G'）和损耗模量（G"）随着 PCNFs 添加量的增加而明显增加。共聚焦激光扫描显微镜（CLSM）的结果证实了 GLT/PCNFs 乳液的稳定机制，涉及 GLT 的界面吸附和 PCNFs 形成的粘弹性网络结构。除了在高离子强度（>100mM）下，引入 PCNFs 可以提高 GLT 乳液的环境稳定性。值得注意的是，PCNFs 有效地避免了 GLT 等电点（pH5）对乳液稳定性的不利影响。
