Flour blending based on crude fat is more crucial than ash content in view of prolonged quality assurrance

Conventionally, the ash content has been a quality control index for flour grading and blending. However, commercially, such a criteria is often found unreliable. In the present study, no significant correlation between the ash- and crude fat contents was found. Conversely, significant correlation was identified between the lipoxygenase activity and the crude fat. Furthermore, from the confirmatory experiment using the standardized synthetic formula, significant relationships were found among the crude fat content, the lipid peroxidative enzymes including the lipoxygenase, hydroperoxide lyase and peroxidase, which apparently could account for the progress of flour off-odor. In contrast, only poor correlation was found with the ash content. In addition, the sensory evaluation in parallel also supported such a result. Conclusively, the crude fat content could be a more reliable parameter than ash content to serve as a novel indicator for flour grading and blending.