Use of Enzymes to Minimize Dough Freezing Damage

Abstract

The purpose of this investigation was to study the effect of pentosanase (Pn), glucose oxidase (Gox), and transglutaminase (TG) on frozen dough (−18 °C) and their influence on minimizing the damage caused by frozen storage. Bread characteristics were analyzed on day 0; after 3 and 9 weeks of frozen storage, specific loaf volume, crust color, and crumb texture and structure were analyzed. Dough expansion capacity and dough stickiness, extensibility, and viscoelasticity were determined. Frozen dough with high levels of Gox developed a larger bread volume than control dough (without added enzyme). The damage percentage caused by frozen storage in Gox samples was lower than in control samples, indicating that Gox increased dough strength and counteracted the depolymerization effect of gluten produced by ice crystal formation and the release of reducing substances from dead yeast cells during freezing. Samples with Pn developed a large bread volume after 9 weeks of frozen storage because of the formation of smaller pentosans, which result from Pn enzyme action. These pentosans were located in protein–starch–CO₂ matrix interfaces and increased dough expansion capacity without gas loss, thus allowing a higher expansion during proofing. The intermediate level of TG was the only one to present a larger bread volume from frozen dough than control. The new isopeptidic bonds introduced by TG in the gluten proteins helped to mitigate the damage caused by dough freezing.