Sudarat Jiamyangyuen, Voranuch Srijesdaruk and W. James Harper

pp. 55 - 64

Abstract

In a study of rice bran protein concentrate (RBPC) preparation, the alkaline extraction was performed. The objectives of this study were to determine the optimal extracting conditions of RBPC and apply
RBPC into a bread recipe in order to improve bread quality and make acceptable product to consumers. The
design used in extraction was a central composite design. The response surface methodology was chosen to
graphically express the relationship between pH and extraction time with the output variables of protein
content and percent yield of RBPC. It was found that optimal extracting conditions were pH 11 and 45 min.,
resulting in 69.16% protein content and 8.06% yield of RBPC. When incorporating 1-5% of RBPC in a
bread recipe, the weight loss and microbial counts of breads were decreased compared to those of control
bread. The higher protein content and fiber in bread was corresponding to the amount of RBPC added.
Therefore, adding RBPC can significantly increase protein and fiber content in bread. However, results from
sensory evaluation showed that adding more than 1% of RBPC decreased the liking scores of color, taste,
odor, texture, and overall liking. The results of this study could be used as a basic knowledge of RBPC
utilization in other food products.

Keywords

• rice bran protein concentrate
• Central Composite Design
• response surface methodology
• bread