Application of flow-injection analysis in the on-line monitoring of sugars,lactic acid,protein and biomass during lactic acid fermentations

A laboratory system for the on-line monitoring of important lactic acid fermentation variables is described. The system contains flow-injection analysers for glucose, lactose, galactose, lactate and protein and a continuous-flow analyser for the biomass concentration. The sugar and lactate analysers are based on enzymatic reactions involving oxidases followed by chemiluminescence detection of the hydrogen peroxide formed. The protein analyser is based on the biuret reaction. The system has been used to monitor many fermentation experiments, and some results are presented as examples.