Natural fermentation of wheat flours

Flour–water mixes (1:2) from each bread (BB) flour, whole wheat (WW) flour or a 1:1 mixture of the two (BW) were fermented at 25, 30, and 35 °C. At 25 °C, fermenting BB and WW flours had the longest (7.2 h) and the shortest (1.5 h) lag phase periods (no net change in pH), respectively. At 35 °C, none of the flours had a lag phase. Increase in temperature from 25 to 35 °C reduced the fermentation time (pH 5.0), of BB, BW and WW flours by 6.8-fold (from 28.6 to 4.2 h), 3.6-fold (11.2–3.1 h) and 2.9-fold (8.7–3.0 h), respectively. The developed mathematical model equations of the fermentation consist of an application of predictive microbiology to the Baking Industry. The mathematical model equations also enable the prediction of attainable pH values as well as fermentation times at different temperatures. The temperature quotients (Q10) for the range of temperatures of 25–35 °C indicated that a 10 °C change in temperature had about a 2- to 7-fold effect on the fermentation rate of the flours based on pH measurements.