Chitin nanofibers improve the stability and functional performance of Pickering emulsions formed from colloidal zein.
Chitin nanofibers improve the stability and functional performance of Pickering emulsions formed from colloidal zein.
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DOI：
10.1016/j.jcis.2021.01.017
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发表时间：
2021-01
影响因子：
9.9
通讯作者：
Gege Sun;Xiaoke Liu;D. Mcclements;Shilin Liu;Bin Li;Yan Li
中科院分区：
文献类型：
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作者：
Gege Sun;Xiaoke Liu;D. Mcclements;Shilin Liu;Bin Li;Yan Li
由于消费者对更天然产品的需求，对由生物聚合物颗粒配制皮克林乳液的兴趣越来越大。基于蛋白质的胶体颗粒可用于此目的，但它们易于在其等电点（pI）附近的pH值下聚集，这限制了它们的应用。在这项研究中，使用甲壳素纳米纤维（ChNFs），以提高由玉米醇溶蛋白胶体颗粒（ZCPs）制备的Pickering乳液的pH稳定性的可能性进行了研究。首先，研究了ChNF和ZCP之间形成的复合物的形态和界面性质随pH（3-9）的变化。在pH ≥ pI条件下，ChNFs的存在降低了ZCPs的聚集和沉淀趋势，这归因于静电复合物的形成。复合粒子的接触角可以通过改变它们的组成来优化。例如，在pH 6下，接触角从ZCP的74°增加到ZCP/ChNF（5：1比率）的85°，这改善了它们稳定油滴的倾向。布鲁斯特角显微镜表明，ZCP/ChNF复合物在空气-水界面处具有棒状和/或颗粒状结构，这与在本体水相中观察到的那些不同。由ZCP/ChNF复合物形成的Pickering乳液比由ZCP或ChNF形成的Pickering乳液具有更好的稳定性，特别是当pH接近或大于pI时。动物体外消化研究表明，在模拟胃肠道中，界面复合物的存在使油滴的脂肪分解减少了约11%。ZCP/ChNF复合物在pH ≥ pI时可形成高内相皮克林乳液（HIPPEs），能够保护不饱和脂质免受氧化。总体而言，我们的研究结果表明，甲壳素纳米纤维可用于改善由胶体玉米醇溶蛋白形成的皮克林乳液的pH稳定性，以及调节其功能性能。
There is growing interest in formulating Pickering emulsions from biopolymer particles due to consumer demand for more natural products. Protein-based colloidal particles can be used for this purpose, but they are prone to aggregate at pH values around their isoelectric point (pI), which limits their application. In this study, the possibility of using chitin nanofibers (ChNFs) to improve the pH stability of Pickering emulsions prepared from zein colloidal particles (ZCPs) was investigated. Initially, the morphology and interfacial properties of the complexes formed between ChNFs and ZCPs were studied as a function of pH (3–9). The tendency of the ZCPs to aggregate and sediment at pH ≥ pI was reduced in the presence of ChNFs, which was attributed to the formation of electrostatic complexes. The contact angle of the composite particles could be optimized by altering their composition. For instance, the contact angle increased from 74° for ZCPs to 85° for ZCP/ChNF (5:1 ratio) at pH 6, which improved their tendency to stabilize the oil droplets. Brewster angle microscopy indicated that ZCP/ChNF complexes had rod-like and/or particulate structures at an air-water interface, which were different from those observed in the bulk aqueous phase. Pickering emulsions formed from ZCP/ChNF complexes had better stability than those formed from ZCPs or ChNFs, especially when the pH was close to or greater than the pI. Anin vitrodigestion study showed that the presence of the interfacial complexes reduced the lipolysis of the oil droplets by about 11% in a simulated gastrointestinal tract. High internal phase Pickering emulsions (HIPPEs) could be formed from ZCP/ChNF complexes at pH ≥ pI, which were able to protect unsaturated lipids from oxidation. Overall, our results show that chitin nanofibers can be used to improve the pH stability of Pickering emulsions formed from colloidal zein, as well as to modulate their functional performance.