The use of infrared reflectance spectroscopy for the automatic continuous monitoring and control of whey ultrafiltration processes

Abstract

A system, based on the infrared reflectance spectroscopic method for the rapid, simultaneous determination of protein, fat, carbohydrate, nonprotein nitrogen and total solids in milk and liquid dairy products, has been developed for continuous analysis of liquid streams for those components. These analyses are used to predict and to control the composition of the whey protein concentrate during ultrafiltration. The ratio of protein to total solids in the concentrate is controlled automatically by a valve in the product outlet line which is adjusted by feedback of the analytical data. The concentration data have also been used to provide alarm systems for the measurement of deterioration, or total failure, of the ultrafiltration membranes. The analytical system has been designed to operate on a whey ultrafiltration plant in continuous operation, with automatic sampling, relevant calibration and CIP (cleaning in place), so that it can be operated with minimum supervision. The whey ultrafiltration process is an example of many processes that, with little modification of the analytical instruments, can be monitored and controlled. Thus concentration of ethanol, CO 2 or of some specific compound, can be measured and used to control many other processes including fermentation and hydrogenation.