Determination of protein composition in milk by mid-infrared spectrometry

Abstract

The fine milk composition is currently studied with attention, some components being of a particular interest. To get a better description of these components, it is necessary to have rapid and reliable methods to analyze several hundreds of milk samples in order to estimate genetic and environmental effects on milk quality. An innovative method based on liquid chromatography coupled with mass spectrometry was developed to identify and quantify the main milk proteins and some works are now on-going to determine milk protein composition from MIR (Mid Infra-Red) spectra usually obtained by milk analysing laboratories. The first results show that it is possible to estimate each of the 4 casein contents with a good accuracy, especially in ewe’s and cow’s milk. By contrast, it seems more difficult to estimate the whey proteins contents. Some improvements are under evaluation to enhance the performance of these equations. This study which is part of the PhenoFinlait programme was funded by Apis-Gene, CASDAR, CNIEL, FranceAgriMer, France Genetique Elevage, French Ministry of Agriculture and French Ministry of Research (National Agency for Research).