title: Impact of amylases on biopolymer dynamics during storage of straight-dough wheat bread.
abstract: When Bacillus stearothermophilus α-amylase (BStA), Pseudomonas saccharophila α-amylase (PSA), or Bacillus subtilis α-amylase (BSuA) was added to a bread recipe to impact bread firming, amylose crystal formation was facilitated, leading to lower initial crumb resilience. Bread loaves that best retained their quality were those obtained when BStA was used. The enzyme hindered formation of an extended starch network, resulting in less water immobilization and smaller changes in crumb firmness and resilience. BSuA led to extensive degradation of the starch network during bread storage with release of immobilized water, eventually resulting in partial structure collapse and poor crumb resilience. The most important effect of PSA was an increased bread volume, resulting in smaller changes in crumb firmness and resilience. A negative linear relation was found between NMR proton mobilities of water and biopolymers in the crumb and crumb firmness. The slope of that relation gave an indication of the strength of the starch network.
authors.affiliation: Laboratory of Food Chemistry and Biochemistry, Leuven Food Science and Nutrition Research Centre (LFoRCe), KU Leuven, Kasteelpark Arenberg 20, B-3001 Leuven, Belgium. geertrui.bosmans@biw.kuleuven.be
authors.forename: Geertrui M
authors.initials: GM
authors.lastname: Bosmans
authors.forename: Bert
authors.initials: B
authors.lastname: Lagrain
authors.forename: Ellen
authors.initials: E
authors.lastname: Fierens
authors.forename: Jan A
authors.initials: JA
authors.lastname: Delcour
mesh_terms: D001412:Bacillus subtilis / Q000201:enzymology; D001426:Bacterial Proteins / Q000378:metabolism*; D001530:Belgium; D001939:Bread / Q000032:analysis*; D055598:Chemical Phenomena; D003296:Cooking; D004044:Dietary Proteins / Q000737:chemistry / Q000378:metabolism*; D063427:Food Quality; D061353:Food Storage; D001411:Geobacillus stearothermophilus / Q000201:enzymology; D055550:Protein Stability; D011549:Pseudomonas / Q000201:enzymology; D055314:Seed Storage Proteins / Q000737:chemistry / Q000378:metabolism*; D000516:alpha-Amylases / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D004044:Dietary Proteins; D055314:Seed Storage Proteins; D000516:alpha-Amylases