During the industrial production, yeast reproduces very rapidly and in big quantities on a sugar substrate composed of sugar beet molasses.The process occurs in successive steps and increasing volumes, from laboratory tests to the final step consisting in the commercial fermentation.
It is therefore important to monitor the evolution of the cell mass during fermentation. In the past this control consisted in spot tests on sample batches, followed by laboratory tests; nowadays it is performed with photometers that continuously monitor the correct evolution of the growth curve in time (optical density) in relation to the amount of living cells. Endress+Hauser process photometers exploit different light spectra to ensure accurate and reproducible measurements.
They feature hygienic design, high resistance at temperatures and pressures, and they can be calibrated directly in line and integrated in continuous processes. The OUSBT66 photometric sensor, for instance, is based on NIR absorption.