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

Abstract

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.

Serratia marcescens Causes the Brown Discoloration of Frozen Steamed Stuffed Buns during Resteaming

“…The moisture content and a W did not differ (Figure ). The pH values of unspoiled samples were found to be consistent with those reported previously for frozen steamed breads, while the spoiled samples displayed lower pH values.…”

“…The moisture content and a W did not differ (Figure 2). The pH values of unspoiled samples were found to be consistent with those reported previously for frozen steamed breads, 5 while the spoiled samples displayed lower pH values. Microbiological characterization of unspoiled and spoiled samples revealed 100,000-fold higher cell counts of bacteria in spoiled buns when compared to unspoiled buns (Table 1).…”

“…In contrast, the a W and moisture content of the surface of FSSBs provide a favorable environment for bacterial proliferation . The pH values of unspoiled samples were consistent with those reported previously for frozen steamed breads, while the spoiled samples displayed lower pH values. The reduction in pH of the spoiled samples indicates the growth of acid-producing bacteria or yeast during the storage of FSSBs.…”

“…4 Nevertheless, the FSSB is prone to quality deterioration, including cracking, reduced elasticity, crust discoloration, and loss of flavor, after undergoing processes like fast-freezing, frozen storage, or resteaming. 5 Brown patches can manifest on the crust of FSSBs during resteaming. This sporadic defect occurs exclusively on the crust, presenting an uneven and irregular shape with predominant yellow or brown spots.…”

“…The FSSB is favored by consumers because of its convenience and long shelf life . Nevertheless, the FSSB is prone to quality deterioration, including cracking, reduced elasticity, crust discoloration, and loss of flavor, after undergoing processes like fast-freezing, frozen storage, or resteaming …”