A A C C   2 0 0 0   A n n u a l   M e e t i n g

Steamed bread is popular in many Asia-Pacific countries. The texture and exterior shape varies depending on the type or style of steam bread being produced. Most northern-style steamed breads are round in shape, with a dense crumb and firm texture. Both processing conditions and flour quality significantly affect end-product quality. Therefore to objectively evaluate the suitability of a flour for steamed bread, it is important that reproducible processing methods be used to minimize processing effects. Rounding has been identified as a critical processing step which influences the overall quality characteristics of steamed bread. In this study, doughs prepared from different mixing times and water absorption levels were rounded by either hand or machine (Brabender Extensograph dough homogenizer), and the resulting steamed breads evaluated for exterior appearance, crumb structure, and textural properties. The results showed that the rounding method had a significant effect on crumb structure. Hand-rounded breads had a more uniform crumb structure than those rounded by machine. They were also more symmetrical in shape and smoother in surface than machine-rounded breads, especially at low water absorption levels. There was, however, no significant difference in textural properties between the two rounding methods. Mixing time was found to significantly affect the texture of steamed breads rounded by both methods. Steamed bread prepared from the undermixed dough had low springiness scores and a sticky texture. Water absorption levels had a significant impact on the exterior appearance of the final product, especially for those made by machine-rounding. For both rounding methods, steamed breads made from either low or high water absorption doughs had poor crumb structure. Although better results were achieved with hand-rounding, this method is highly operator dependent. A proper rounding device, such as modification of the Extensograph dough homogenizer, needs to be developed in order to achieve consistent rounding results.