Submitted to: Annual Meeting of the Institute of Food Technologists
Publication Type: Abstract Only
Publication Acceptance Date: 2/22/2008
Publication Date: N/A
Technical Abstract: Wheat flour mainly consists of the starchy endosperm of the kernel, and contains starch (70-80%), proteins (8-18%), lipids (1.5-2.5%) and non-starch polysaccharides (2-3%). Arabinoxylans (AXs) are the main non-starch polysaccharides found in wheat flour. The structure of AX is a linear backbone of ß-1,4-linked xylose, with a single arabinose residue on C-3 or on both C-2 and C-3. Furthermore, some of the arabinose residues are esterified with ferulic acid. Even though AX abundance in flour is relatively lower, it has significant impact on the physicochemical properties, such as water absorption. Studies have shown that degradation of AX in refrigerated dough has negative affect on quality. To prevent the quality problems in refrigerated dough, it is important to investigate the structural changes, at the molecular level, in the AX during refrigerated dough storage. The objectives of this research were to structurally characterize the AXs from refrigerated dough samples and determine any correlations between the AX structural changes and changes in dough quality. High Performance Liquid Chromatography was used to estimate molecular weight changes, Gas Chromatography-Mass Spectrometry was used to determine monosaccharide composition of isolated AX samples, and Nuclear Magnetic Resonance Spectroscopy was used to determine the degree of arabinose substitutions. We observed that the molecular weight of the AXs was decreasing during the extended storage, and we detected changes in arabinose to xylose ratio for water extractable and unextractable AXs. The ratio of unsubstituted xylose in water extractable AXs increased during storage. These results showed that changes in AX chemistry is correlated to the degree of dough syruping.