Studies on the Properties and Cooking on Natural Polymer Polyionic Complexes

2003 Fiscal Year Final Research Report Summary

• Project/Area Number: 14580145
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: 食生活
• Research Institution: Otsuma Women's University
• Principal Investigator: ICHIKAWA Tomoko Otsuma Women's University, Department of Home Economics, Professor, 家政学部, 教授 (30141295)
• Project Period (FY): 2002 – 2003
• Keywords: polyionic complex / chitosan / carboxymethyl cellulos / degree of swelling / FT-IR spectra analysis / poly(galacturonic acid) / TMA / SS analysis

Research Abstract

In the present work, by the use of natural polymer derivatives such as polysaccharides without chemical crosslinks that prevent their dissolution in water, were performed a series of experiments on synthesis of polyionic complexes with ionic interaction between two polymers having opposite ionic properties. Their water-sorption behaviors and some physical properties, as well as the application to food materials, were investigated.
The natural polymer polyionic complexes were formed, consisting of components mentioned below. As the cationic component, chitosan which is a chain of ring structures, or poly(lysine) which is a linear flexible chain, and as the anionic component, poly(galacturonic acid) or carboxymethyl cellulose (= CMC), both of which are chain of ring structures, were used. Several complex films were prepared by casting from solution which contained the above components at different ratios.
Water sorption behavior was significantly affected by the balance between the amounts of the cationic and the anionic groups in these polymers. The degree of chitosan/CMC complex film swelling was minimum, when the amounts of the cationic and anionic groups in this polymer were balanced at 1:1 ratios. And the degree of swelling was maximum when the amounts of the cationic and anionic groups in this polymer were balanced at 8:2 ratios. The results of the analysis of structural changes in complexes by FTIR spectra showed the intermolecular interactions between cationic and anionic groups in the polymers.
Further, the comparison of the form of water absorbed in various polyionic complexes by means of DSC, and the examination of properties such as compressive moduli of swollen complex films should be carried out for the evaluation of of the availability to food materials.