Quality evaluation of steam reheated frozen steamed bread

With advantages of long shelf life and high convenience, frozen steamed bread (FSB) is suitable for commercialization and industrialization. However, FSB has to be reheated before consumption. Since steam reheating is the most commonly used method for steamed bread reheating, the quality variation of FSB during the steam reheating process was evaluated in this research. Because of the simultaneous energy and moisture transfer, both the temperature and moisture content of reheated FSB gradually increased during steaming process. Starch gelatinization and crystallinity results showed that the retrograded starch was gelatinized again during steaming process. With the increase of steam reheating time, the increase of springiness and resilience as well as the decline of hardness and chewiness indicated the improved textural properties of steamed bread. Considering the sensory evaluation, the optimal steaming time was about 12 min with a maximum sensory evaluation score of 93.3. However, the springiness, resilience and sensory evaluation results of reheated FSB were still lower than those of the fresh steamed bread. The microstructure results showed that the damaged gluten network of FSB could not be recovered by steam reheating.