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.

Intact and Damaged Wheat Starch and Amylase Functionality During Multilayered Fermented Pastry Making

“…Inclusion of amylase in CF recipes was expected to result in an increase in the area of population A and a decrease in the area of population B, as noted for bread crumb samples by Bosmans et al. (). Especially in the case of BsuA use, Bosmans et al.…”

“…In addition to an increased mobility of amylose (fragments) as outlined by Bosmans et al. (), a lessened hindering of AM crystallization by hydrolysis of the leached AP fraction may also partly explain these changes.…”

“…Especially in the case of BsuA use, Bosmans et al. () attributed these changes to increased mobility of AM (fragments) after hydrolysis, which results in a more pronounced AM network and thus an increase in the portion of rigid CH‐protons of crystalline starch. Earlier, Leman et al.…”

“…A more pronounced release of amylopectin (AP) from DS possibly hinders amylose (AM) crystallization in DF samples. The endo‐action of amylase renders hydrolysed AM fragments more mobile (Bosmans et al, ) in all samples, resulting in a more extensive AM network. Furthermore, hydrolysis of leached AP from the DF samples limits the proposed hindrance by AP.…”

Staling of potato and wheat steamed breads: physicochemical characterisation and molecular mobility

“…According to Bosmans et al . (b), T 21 contained CH protons of gluten and exchanging protons of confined water, starch and gluten, and T 22 consisted of mobile exchanging protons of water, starch and gluten in the formed gel network, and the most mobile population, T 23 , contained lipid protons. A 21 , A 22 and A 23 were the corresponding area fractions respectively.…”