Bubble growth and collapse in pre-fermented doughs during freezing, thawing and final proving

Effects of different storage temperatures and time on frozen storage stability of steamed bread

BACKGROUNDS

This research intended to explore the effects of different frozen storage temperatures and time on the stability of steamed bread. The quality characteristics, moisture content and microstructure of steamed bread were determined after quick-frozen for 30 min at -32 °C and frozen storage at -6, -12, -18, -24 and -30 °C for 1-4 weeks.

RESULTS

When the frozen storage temperature is lower, the moisture content, specific volume, pH and the strong bound water in the steamed bread increase, the water loss rate and the contents of freezable water, the weak bound water and free water decreased. With the extension of frozen storage time, the pH value and water loss of steamed bread first increased and then decreased, while the trend of water content was opposite. The specific volume, cohesion and elasticity of steamed bread decreased, while the freezable water content, hardness and chewiness increased. The bound water of steamed bread gradually migrated to free water. In addition, the longer the frozen storage time and the higher the temperature, and the more serious the damage to the microstructure was.

CONCLUSION

The shelf life of steamed bread frozen storage at -12 °C could be up to 3 weeks, and the quality of steamed bread stored at -30 °C for more than 3 weeks was the best. © 2022 Society of Chemical Industry.

Optimized Fermentation and Freezing Conditions for Ready-to-Proof and Ready-to-Bake Frozen Dough of Sweet Bread

The processing conditions for ready-to-proof (RTP) and ready-to-bake (RTB) frozen sweet bread doughs were optimized using response surface methodology. A central composite design determined four factors and the tested range for each factor: a first fermentation time of 15~45 min, a second fermentation time of 30~90 min, a freezing temperature of −45~−25 °C, and a freezing time of 30~90 min. Sweet bread produced with these doughs was evaluated by bread weight, moisture content, crust color, height, volume, and firmness. Both the RTP and RTB doughs resulted in equal bread volume and height to the fresh dough, indicating excellent frozen stability. The first and second fermentation times were the significant processing factors for the RTP and RTB doughs influencing representative bread quality attributes based on quadratic models and ANOVA. Fermentation steps appeared to more significantly contribute to the quality of sweet bread made of frozen dough than freezing steps. The optimized RTP and RTB sweet bread dough processing conditions were the long first and second fermentation times for the dough based on a multiple response method and desirability. The optimum processing conditions for the RTP and RTB doughs were 44.7 min for the first fermentation time, 86.3 min for the second fermentation time, a −32.8 °C freezing temperature, and an 85.5 min freezing time.

Application of rich in β-glucan flours and preparations in bread baked from frozen dough

This study aims to define the changes in the quality of bakery products depending on the β-glucan source and its contribution using bake-off technology. The examined bread was enriched with a 10% addition of oat flour, barley flour, oat fibre preparation, and barley fibre preparation. Bread was tested for rheological parameters, baking performance, hardness and springiness, water content, specific volume, porosity, crust and crumb colour, and β-glucan content. In the executed research, the adverse effect of this component on the formation of gluten network and hardness of the crumb was observed. In the double compression test, it was shown that the highest hardness on the day of baking was characterized by the bread with the addition of barley preparation. The fastest rate of staling was observed in the bread with additional barley flour that was affected by the highest amount of β-glucan. A significant decrease of the β-glucan level was also found during the technological bake-off process, which can be explained by the activity of enzymes.