Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2004
Publication Date: 7/10/2004
Citation: Fishman, M.L., Cooke, P.H., Chau, H.K., Coffin, D.R., Hotchkiss, A.T. 2004.Pectin networks, clusters and molecules. Meeting Abstract 228th American Chemical Society National Meeting, Philadelphia, PA., August 22-26, 2004. AGFD:19.
Technical Abstract: Time dependent microwave assisted extractions of pectin from lime and orange albedo, have revealed that with increasing time of heating, molar mass and size decreased. In contrast, Mark-Houwink exponents, a measure of the rate of change of the molar volume with molar mass, increased with time. Based on these experiments it is hypothesized that pectin network structures gradually break down during the extraction process with increasing heating time. Initially networks degenerate to partially formed networks (clusters or branched structures) and finally to a mixture of linear molecules in the shape of rods, segmented rods and kinked rods. Additional evidence for this model was obtained from electron micrographs of pectin deposited on mica from solution which showed the presence of all the structures described above. Furthermore, pectin imaged in native sugar acid gels by atomic force also revealed that pectin existed in these gels as partially formed networks.