Large deformation rheology of gelatin gels

被引:102
作者
Bot, A
vanAmerongen, IA
Groot, RD
Hoekstra, NL
Agterof, WGM
机构
[1] Unilever Res. Lab. Vlaardingen, NL-3133 AT Vlaardingen
[2] Unilever Res. Port Sunlight Lab., Bebington, Wirral L63 3JW, Quarry Road East
关键词
rupture; fracture; gelatin; biopolymer; protein; gel;
D O I
10.1016/0966-7822(96)00011-1
中图分类号
O63 [高分子化学(高聚物)];
学科分类号
070305 ; 080501 ; 081704 ;
摘要
We studied the linear and the non-linear elastic behaviour, the breaking stress and breaking strain of gelatin gels as a function of a number of experimental conditions: gelatin concentration, gelatin bloom value, ageing time, ageing temperature, pH, NaCl and CaCl2 concentration, whey protein concentration, the amount of pre-shearing, strain rate or compression speed, using both shear deformation and compression. We analyzed the stress-strain curves using the BST-equation (Blatz et al., Trans. Sec. Rheol. 18, (1974) 145) and extracted a parameter that characterizes the linear elastic behaviour at small deformations (the moduli E or G) and one that characterizes the non-linear elastic behaviour at large deformations (the elasticity parameter n). The phenomenological BST equation describes rheological experiments adequately both in shear deformation and in compression. We found that the modulus correlates with the breaking stress. For the non-linear elastic properties of gelatin, we found that the elasticity parameter n correlates with the breaking strain. Qualitatively, the non-linear elastic properties can be explained by assuming that the gelatin chains are partially in a crystalline triple helix state (the cross-links) and partially in a random coil state (the network bonds): the more extensive the rigid cross-link regions, the shorter and more stretched the network bonds become as a result of an externally applied deformation. The network bonds behave as anharmonic springs under extreme extension. Manipulation of the breaking strain was attempted in two ways: (i) by changing the (non-linear) elasticity parameter of the gel: this is possible by using a gel that has been further aged; (ii) by adding defects to the gel structure: this is possible by either pre-shearing the gel or by adding whey protein particles. The pre-shearing gives rise to a temporary effect, the addition of whey protein particles to a permanent effect. Copyright (C) 1996 Elsevier Science Ltd.
引用
收藏
页码:189 / 227
页数:39
相关论文
共 37 条
[1]   MECHANISM OF GELATION OF GELATIN - INFLUENCE OF CERTAIN ELECTROLYTES ON THE MELTING POINTS OF GELS OF GELATIN AND CHEMICALLY MODIFIED GELATINS [J].
BELLO, J ;
RIESE, HCA ;
VINOGRAD, JR .
JOURNAL OF PHYSICAL CHEMISTRY, 1956, 60 (8-9) :1299-1306
[2]   CONTINUOUS-TIME SIMULATION OF TRANSIENT POLYMER NETWORK MODELS [J].
BILLER, P ;
PETRUCCIONE, F .
JOURNAL OF CHEMICAL PHYSICS, 1990, 92 (10) :6322-6326
[3]   STRAIN ENERGY FUNCTION FOR RUBBER-LIKE MATERIALS BASED ON A GENERALIZED MEASURE OF STRAIN [J].
BLATZ, PJ ;
SHARDA, SC ;
TSCHOEGL, NW .
TRANSACTIONS OF THE SOCIETY OF RHEOLOGY, 1974, 18 (01) :145-161
[4]   Effect of deformation rate on the stress-strain curves of gelatin gels [J].
Bot, A ;
vanAmerongen, IA ;
Groot, RD ;
Hoekstra, NL ;
Agterof, WGM .
JOURNAL DE CHIMIE PHYSIQUE ET DE PHYSICO-CHIMIE BIOLOGIQUE, 1996, 93 (05) :837-849
[5]   BRILLOUIN LIGHT-SCATTERING FROM A BIOPOLYMER GEL - HYPERSONIC SOUND-WAVES IN GELATIN [J].
BOT, A ;
SCHRAM, RPC ;
WEGDAM, GH .
COLLOID AND POLYMER SCIENCE, 1995, 273 (03) :252-256
[6]  
BOT A, 1996, GUMS STABILISERS FOO, V8, P117
[7]   GELATION IN PHYSICALLY ASSOCIATING BIOPOLYMER SYSTEMS [J].
CARNALI, JO .
RHEOLOGICA ACTA, 1992, 31 (05) :399-412
[8]  
CLARK AH, 1987, ADV POLYM SCI, V83, P57
[9]  
DJABOUROV M, 1993, J PHYS II, V3, P611, DOI 10.1051/jp2:1993155
[10]   THE EFFECT OF ENTANGLEMENTS IN RUBBER ELASTICITY [J].
EDWARDS, SF ;
VILGIS, T .
POLYMER, 1986, 27 (04) :483-492