The cumulative ash curve: a best tool to evaluate complete mill performance.

Slick test is carried out by a flour miller to
qualitatively segregate the flour from different streams in a
roller flour mill. This test is done manually by pressing
flour samples on tray using thin bladed paddle (the slick)
and inspecting color or dress of the sample. However, the
test is subjective and totally depends on human judgment.
Cumulative ash curve relates to cumulative flour ash
content and cumulative flour yield, which could help a
flour miller to be more precise while selecting flour
streams for different needs. In this study, cleaning and
conditioning of wheat was carried out in the pilot plant of
International School of Milling Technology (ISMT). Further,
roller flour milling of wheat was done. Flour from
different streams (four breaks, five reductions) was collected.
Each flour stream was analyzed for ash content using
standard AACC methods. The analytical values of ash
content were used to plot the cumulative ash curve. It was
found that ash content increased in the break passages from
first to last break, with exception of first break (ash content
0.71%). An increase in percentage of ash was observed in
the reduction passages (C1 to C5), however, C3 ash
(0.76%) was slightly higher than that of C4 (0.65%).
Higher yield of flour with minimum ash content was
obtained from the front reduction passages C1 and C2;
whereas, the break passages and the tail end reduction
passages produce less flour with higher ash content.