没食子酸和芦丁对鱼皮明胶凝胶的溶胀性及水的状态的影响

研究没食子酸和芦丁对鱼皮凝胶的溶胀性及水的状态的影响。结果表明,没食子酸和芦丁均可使凝胶的平衡溶胀率降低,以芦丁的影响较显著。在凝胶溶胀初期,未交联凝胶和没食子酸添加量20mg/g凝胶以及芦丁添加量为6和8mg/g凝胶均表现非Fick扩散过程,而30mg/g没食子酸交联的凝胶表现Fick扩散过程。同时发现,无论是未交联凝胶还是多酚交联凝胶,在溶胀过程中均是凝胶高分子链的松弛过程为速控步骤。通过差示扫描量热法(DSC)对多酚交联凝胶中水的状态分析发现,没食子酸和芦丁对凝胶的平衡水分含量没有明显影响,但可改变凝胶中可冻结水和非冻结结合水的分布。20和30mg/g的没食子酸使凝胶中非冻结结合水含量降低,而6和8mg/g的芦丁却使凝胶中非冻结结合水含量升高。 

Effect of gallic acid and rutin on the swelling behavior and state of water in gelatin from fish skin

The effect of gallic acid and rutin on swelling behavior and state of water in gelatin from fish skin was investigated.The results showed that the equilibrium swelling ratio of gel decreased with the introduction of gallic acid and rutin,but it was evident in gelatin treated with rutin.In the primary swelling process,the swelling behavior of untreated gelatin and gel treated with 20 mg/g dry gelatin gallic acid,and 6,8mg/g dry gelatin rutin followed the Fick's law of diffusion,while that of gel containing 30 mg/g dry gelatin gallic acid obeyed the non-Fick's law of diffusion.It was found that the relaxation of polypeptide chains was the rate-determining step in the whole swelling process of gelatin with and without cross-linking agents.Differential scanning calorimetry( DSC) was employed to analyse the state of water in the gels.The results indicated that gallic acid and rutin did not have obvious effect on equilibrium water content of gel,but showed marked effect on the distribution of frozen and non-frozen water.The non-frozen water was lower after addition of 20 or 30 mg/g dry gelatin gallic acid,while it was higher after 6 or8 mg/g gelatin rutin was introduced.