Mnogo je faktora koji utječu na bjelinu brašna, kao što je sorta pšenice, tehnički proces, aditiva, temperatura, vrijeme skladištenja, itd; ali sljedeći čimbenici uglavnom utiču na bjelinu brašna:

A. Flour storage temperature

For the same wheat and additive, izbjeljivanje brašna zahtijeva različita razdoblja ljeti i zimi. To je uglavnom zbog učinka izbjeljivanja benzoil peroksida (BPO) odnosi se na temperaturu okoline. Kada je volumen dodavanja BPO 60mg, reakcija izbjeljivanja može se završiti u 24 sati na temperaturi od 30℃, dok se reakcija izbjeljivanja može završiti u 6 hours under the temperature of 50℃. However, in winter it may require 48 hours or even longer.

B. Moisture content

The optimum moisture content for additive using is approximately 15%, especially for Grade 1 and Grade 2 brašno. Excessively high or low moistures are neither ideal for whitening. When the moisture content is too high, BPO resolves fast and the resultant reactive oxygen flows out participating in the reaction completely; when the moisture content is too low, BPO hasn’t resolved completely when being sold and so it cannot give full play to its whitening effect. Therefore, excessively high and low moisture contents influence BPO’s whitening effect.

C. BPO’s flowing property

Flour additive’s flowing property is related to the inorganic salt when diluting BPO. The better the BPO’s flowing property is, the evener the additive is. Meanwhile additive’s flowing property has a great bearing on its fineness. The finer the additive is, the evener it is in the flour, the better the whitening effect is. Otherwise, there may be “zebra stripes” phenomenon which affects flour quality seriously and pose a hidden problem.

D. Flour fineness

Flour particle size has a great influence on its whiteness. Shading coefficient test indicates that fine particle appears whiter than coarse particle; fine particle flour appears especially whiter if additive has been added.