title: Biopolymer interactions, water dynamics, and bread crumb firming.
abstract: To establish the relationship between biopolymer interactions, water dynamics, and crumb texture evolution in time, proton mobilities in starch and gluten model systems and bread were investigated with NMR relaxometry. Amylopectin recrystallization was observed as an increased amount of fast-relaxing protons, while network strengthening and changes in water levels were noted as a reduced mobility and amount, respectively, of slowly relaxing protons. Amylopectin recrystallization strengthened the starch network with concomitant inclusion of water and increased crumb firmness, especially at the beginning of storage. The inclusion of water and the thermodynamic immiscibility of starch and gluten resulted in local gluten dehydration during bread storage. Moisture migration from crumb to crust further reduced the level of plasticizing water of the biopolymer networks and contributed to crumb firmness at longer storage times. Finally, we noted a negative relationship between the mobility of slowly relaxing protons of crumb polymers and crumb firmness.
authors: Laboratory of Food Chemistry and Biochemistry and Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium. bosmans@biw.kuleuven.be
authors: Geertrui M
authors: GM
authors: Bosmans
authors: Bert
authors: B
authors: Lagrain
authors: Nand
authors: N
authors: Ooms
authors: Ellen
authors: E
authors: Fierens
authors: Jan A
authors: JA
authors: Delcour
mesh_terms: D000687:Amylopectin / Q000737:chemistry; D001704:Biopolymers / Q000737:chemistry*; D001939:Bread / Q000032:analysis*; D002152:Calorimetry, Differential Scanning; D005511:Food Handling / Q000379:methods; D005983:Glutens / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013816:Thermodynamics; D014867:Water / Q000737:chemistry*; D014961:X-Ray Diffraction
chemical_list: D001704:Biopolymers; D014867:Water; D005983:Glutens; D000687:Amylopectin