Phase separation in aqueous gelatin-κ-carrageenan systems
Phase separation in aqueous gelatin-κ-carrageenan systems
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DOI：
10.1016/s0268-005x(99)00037-5
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发表时间：
1999-11-01
影响因子：
10.7
通讯作者：
Gonçalves, MP
中科院分区：
文献类型：
--
作者：
Antonov, YA;Gonçalves, MP
在低离子强度 (mu = 0.002)、pH = 5.0（接近等离子点 (iip = 4.8)）和总生物聚合物浓度 (TBC) 低于 0.2% w/w 的情况下，明胶与 kappa-卡拉胶 (kappa CG) 相容。当 TBC 高于 0.2% w/w 时，明胶与 kappa CG 形成水不溶性复合物，并且观察到相分离，与 pH (3.0-9.0) 和温度无关，其特征是共沉淀程度相对较小，当初始混合物中的 TBC 增加时，共沉淀程度也会增加。当 pH = 5.0 时，初始混合物中明胶和 kappa CG 摩尔比为 3.0 时，沉淀复合物的产量最大。复合物通过静电相互作用形成并稳定，而不是通过氢键或疏水相互作用，并且发生“全或无”型复合物形成机制。在 mu = 0.1-0.2 (NaCl) pH 大于或等于 iip 和 313 K 时，在较宽的总生物聚合物浓度范围 (0.01-25% w/w) 中未观察到共沉淀或不相容性。在 mu = 0.35、pH = 5.0 和 313 K 下，当初始混合物中 kappa CG 的浓度高于 0.65% w/w 时，明胶表现出与 kappa CG 的不相容性。在上述条件下，系统的相图表明，即使在非常高的离子强度下，两种生物聚合物也可能存在特定的相互作用。 (C) 1999 Elsevier Science Ltd. 保留所有权利。
At low ionic strength (mu = 0.002), pH = 5.0 (close to the isoionic point (iip = 4.8)) and total biopolymers' concentration (TBC) less than 0.2% w/w, gelatin is compatible with kappa-carrageenan (kappa CG). When TBC is higher than 0.2% w/w, gelatin forms water-insoluble complexes with kappa CG and phase separation is observed independently of pH (3.0-9.0) and temperature, and is characterised by a relatively small degree of co-precipitation, which increases when TBC in the initial mixture increases. At pH = 5.0, the yield of complex precipitated is maximal at a 3.0 molar ratio of gelatin and kappa CG in the initial mixture. The complexes are formed and stabilised via electrostatic interactions, rather than through hydrogen bonds or hydrophobic interactions and an "all or none" type complex formation mechanism takes place. At mu = 0.1-0.2 (NaCl) pH greater than or equal to iip, and 313 K, neither co-precipitation nor incompatibility were observed in an overwide range of total biopolymers' concentration (0.01-25% w/w). At mu = 0.35, pH = 5.0 and 313 K, gelatin exhibits incompatibility with kappa CG when the concentration of kappa CG in the initial mixture is higher than 0.65% w/w. The phase diagram of the system, in the above mentioned conditions, indicates a possible specific interaction of the two biopolymers even at a very high ionic strength. (C) 1999 Elsevier Science Ltd. All rights reserved.