Study of Microstructure of Pectin and Whey Protein Isolate Mixtures under Incompatible Conditions Using Dynamic Light Scattering and Transmission Electron Microscopy
1. Laboratory of Functional Dairy, Ministry of Education and Beijing City, College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China 2. College of Science, China Agricultural University, Beijing 100094, China 3. Centre de Recherche en Science et Technologie du Lait (STELA), Faculté des Sciences de l’Agriculture et de l’Alimentation. Université Laval, Pavillon Paul-Comtois, Sainte-Foy, Québec, Canada G1K 7P4
Abstract：The microstructure of the pectin/whey protein isolate mixtures under incompatible conditions was investigated using dynamic light scattering spectroscopy, transmission electron microscopy and shear-viscosity model. Under the condition of 90 ℃ and pH 7.4, the presence of negatively charged pectin could induce depletion aggregation in a 5% protein solution, and promote phase separation; precisely, when the mass ratio of pectin/whey protein isolate was lower than 0.08, the hydrodynamic size of the aggregates was less than 300 nm, and the system showed Newtonian properties; when the mass ratio was higher than 0.08, the viscosity of the solution increased rapidly, the shear thinning properties became obvious and the size of the aggregates was close to 700 nm.
Key words：Whey protein isolate;Pectin;Viscosity;Shear;Phase separation
冷小京1, 柴 智1, 任发政1，张录达2，Turgeon S L3 . 应用动态光散射和透射电镜研究热力学不相容条件下果胶与乳清蛋白混合体系的微观结构[J]. 光谱学与光谱分析, 2010, 30(08): 2196-2200.
LENG Xiao-jing1, CHAI Zhi1, REN Fa-zheng1, ZHANG Lu-da2, Turgeon S L3 . Study of Microstructure of Pectin and Whey Protein Isolate Mixtures under Incompatible Conditions Using Dynamic Light Scattering and Transmission Electron Microscopy . SPECTROSCOPY AND SPECTRAL ANALYSIS, 2010, 30(08): 2196-2200.
[1] Tolstoguzov V B. Food Hydrocolloids, 1991, 4: 429. [2] Steventon A J, Donald A M, Gladden L F. Biochemistry of Milk Products, 1994, 150: 133. [3] Cayot P, Lorient D. Structures et Technofonctions des Protéines du Lait, London, Paris, New York, Technique & Documentation, Arilait Recherches, Chapter, 1998, 7: 117. [4] Marcotte M, Hoshahili A R T, Ramaswamy H S. Food Research International, 2001, 34: 695. [5] Havea P, Singh H, Creamer L K. Journal of Agricultural and Food Chemistry, 2002, 50: 4674. [6] WU Li-ping, LENG Xiao-jing, SUN Yan, et al(吴丽萍，冷小京，孙 雁，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2010，30(5)：1391. [7] Leng X J, Turgeon S L. Hydrocolloids, 2007, 21: 1014. [8] Pecora R. Dynamic Light Scattering: Applications of Photon Correlation Spectroscopy. New York：Plenum Press, 1985. [9] de Carvalho W, Djabourov M. Rheologica Acta, 1997, 36: 591. [10] Cross M M. Journal of Colloid Science, 1965, 20: 417. [11] Cross M M. Journal of Colloid and Interface Science, 1970, 33: 30. [12] Krieger I M, Dougherty T J. Transactions of the Society of Rheology, 1959, 3: 137. [13] Aguilera J M. Food Technology, 1995, 49(10): 83. [14] Stading M, Langton M, Hermansson A M. Food Hydrocolloids, 1992, 6(5): 455. [15] Tuinier R, Dhont J K G, de Kruif K G. Langmuir, 2000, 16: 1497. [16] Croguennoc P, Durand D, Nicolai T. Langmuir, 2001, 17: 4372.
