Application of infrared spectroscopy to the monitoring of lactose and protein from whey after ultra and nano filtration process

Whey is produced during cheese manufacture some of its constituents are lactose and proteins. In different countries such constituents are separated for use as raw material; some of the processes to separate these components are by ultra and nano-filtration, however most common methods for the determination of lactose and proteins are not accurate. This paper shows that infrared spectroscopy is a good alternative for the quantification of lactose and proteins after ultra-filtration and nano-filtration processes. Linear calibration curves were obtained with this analytical technique for aqueous solutions containing lactose or protein in the range 0 to 20%; after 20% lactose, the solution becomes saturated. Infrared spectroscopy is a rapid and precise method that could be successfully used to quantify these compounds and follow the ultra-filtration and nano-filtration process applied to purify lactose and proteins from whey.