Ahmadi Maede, Madadlou Ashkan, Sabouri Ali Akbar
Department of Food Science & Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Department of Food Science & Engineering, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran; Center of Excellence for Application of Modern Technologies for Producing Functional Foods and Drinks, University College of Agriculture and Natural Resources, University of Tehran, Karaj, Iran.
Food Chem. 2015 May 1;174:97-103. doi: 10.1016/j.foodchem.2014.11.038. Epub 2014 Nov 15.
Micro- and nano-crystalline cellulose (MCC and NCC, respectively) particles isolated from cellulose filter papers via acid digestion were characterised and loaded into a heat-denatured whey protein isolate (WPI) solution which was subsequently cold-set-gelled. Both the MCC and NCC particles were rod-shaped and had higher crystallinity degrees than had the cellulose source they were isolated from. The hydrodynamic diameter of NCC particles was ≈ 15 nm. Fourier transform infrared (FTIR) spectroscopy suggested more surface hydroxyl groups on the NCC than the MCC particles and complete digestion of hemicellulose on the cellulosic substrate by acid. MCC- and NCC-loaded WPI gel matrices were topographically less uniform and contained many more undulations in comparison to the crystal-free counterpart. It was found, using dynamic rheometry and penetration tests, that the crystal loading into WPI gels weakened the texture. Non-covalent interactions between the cellulose crystals and whey protein strands were proposed in the gel structure according to FTIR results.
通过酸消化从纤维素滤纸中分离出的微晶纤维素和纳米晶纤维素（分别为MCC和NCC）颗粒进行了表征，并加载到热变性乳清蛋白分离物（WPI）溶液中，随后进行冷胶凝。MCC和NCC颗粒均为棒状，且结晶度高于其分离来源的纤维素。NCC颗粒的流体动力学直径约为15 nm。傅里叶变换红外（FTIR）光谱表明，NCC颗粒上的表面羟基比MCC颗粒更多，且酸完全消化了纤维素底物上的半纤维素。与无晶体的对应物相比，负载MCC和NCC的WPI凝胶基质在形貌上不太均匀，且包含更多起伏。使用动态流变学和渗透测试发现，向WPI凝胶中加载晶体削弱了质地。根据FTIR结果，在凝胶结构中提出了纤维素晶体与乳清蛋白链之间的非共价相互作用。
