Structural modification of pectin by pectin methyl esterase (PME): Effects on rheological and sensory properties of pectin gels

AGFD 78

Yang Kim, ya1971@empal.com1, Young-Hee Yoo2, Byung-Hoo Lee2, Kwang Ok Kim1, and Sang-Ho Yoo, shyoo@sejong.ac.kr2. (1) Department of Food Science and Technology, Ewha Womans University, 11-1 Daehyung-Dong, Seodaemoon-Gu, Seoul, 120-750, South Korea, (2) Department of Food Science and Technology, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul, 143-747, South Korea
Molecular structure of pectin characterized by molecular weight (MW), galacturonic acid (GA) content, and degree of esterification (DE) profoundly affects its functionality including gelling property. The objective of our study was to investigate the effect of structural changes of pectins by PME on rheological and sensory properties of the modified pectin gels. Three types of pectins (HMP, LMP, and LMAP) were subjected to modification by an orange peel PME. PME-modified pectin gels were obtained under the presence of calcium phosphate, gluconolactone and sucrose. After completing the PME reaction, the DE values of HMP, LMP, and LMAP significantly decreased from 74.5 to 6.3%, from 39.9 to 6.5%, and from 39.1 to 18.0%, respectively. Firmness, elasticity, and chewiness of the pectin gels were drastically increased by PME-modification, while cohesiveness and adhesiveness were decreased. At the comparable level of DE, the larger MW pectin and amidated pectin had greater firmness and springiness.
 

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Division of Agricultural & Food Chemistry

The 232nd ACS National Meeting, San Francisco, CA, September 10-14, 2006