17G-20 |
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B. FERMIN1, J. Radinsky1, and Y. M. Lo2. (1) Department of Nutrition and Food Science/Food Bioprocess Engineering Lab, University of Maryland, 3407 Marie Mount Hall, College Park, MD 20742, (2) Dept. of Nutrition & Food Science, Univ. of Maryland, Food Bioprocess Engineering Lab., 3102 Marie Mount Hall, College Park, MD 20742 Proline and glutamine are the two most abundant amino acids in wheat. The rigid cyclic ring structure of proline prevents the formation of the a helix protein conformation, thereby might contribute to the elastic nature of gluten. Glutamine’s amide side chain has a great capacity for hydrogen bonding, which affects the rheological properties of dough and contributes to the theory that the intermolecular and intramolecular hydrogen bonding in the gluten complex is responsible for the viscoelastic nature of dough. However, no direct correlations between these amino acids and wheat flour properties have yet been reported. The objective was to characterize the roles of proline and glutamine in breadmaking process with regard to its functional attributes. Samples of wheat flour were prepared by grinding the grains of Karl 92, a hard red winter wheat variety, and Sisson 36, a soft red winter wheat variety. Bread samples were prepared following the optimized straight-dough bread-making method from AACC Method 10-10B. Dough textural properties were measured using the TA.XT2i Texture Analyzer. Bread volume and textural properties were determined by AACC Method 74-09. Pairwise mean differences were evaluated using the Tukey’s test (a=0.05). The dough samples with added proline content showed increased stickiness, strength, work of adhesion, and extensibility, whereas increased glutamine content reduced dough stickiness, work of adhesion, and resistance to extension. Proline and glutamine increased bread gumminess, resilience, and cohesiveness but had no effect on firmness. Both proline- and glutamine-treated bread samples showed reduced losses of these amino acids after the breadmaking process. Addition of one amino acid was also found to have protective effects on the other amino acid during breadmaking. Characterizing the roles of proline and glutamine during the process of breadmaking should provide valuable insights on their contributions to the functional properties of wheat dough.
Session 17G, Food Engineering: Physical, chemical and electrical properties
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