2023 Volume 24 Issue 4 Pages 113-117
Measuring protein concentration CP is important for many unit operations at food or bio-industry such as bioreactors, adsorptions, chromatography separations, and concentration operation by ultrafiltration. Although various methods are available, most of them are not suited for measuring high CP. In this paper we have developed a method for continuous monitoring of very high CP by optical rotation (OR). A flow-cell was built based on the standard cell. Linear correlations were confirmed between OR and CP in the range CP = 0 to 20 g/L, the slope of which was similar to that obtained for the batch measurement. As the flow-cell volume is large, the effect of the input signal shape on the output signal was analyzed based on the mechanistic model considering the continuous stirred tank reactor and the plug flow reactor. This method was applied to the continuous monitoring of CP during concentration by ultrafiltration. The measured CP values (CP = 12 to 68 g/L) were in good agreement with the off-line measured values by the absorbance at 280 nm after dilution.
