Application of the MIR for the determination of some chemical parameters in European Emmental cheeses produced during summer

摘要

This study examines the feasibility of using the mid infrared (MIR) spectroscopy for the determination of some parameters in European Emmental cheeses produced in summer from different geographic origins. A total of 72 Emmental cheeses (4 samples from Finland, 6 samples from Germany, 8 samples from Austria, 27 samples from France and 27 samples from Switzerland) were investigated. Total nitrogen (TN), water soluble nitrogen (WSN), non protein nitrogen (NPN), sodium chloride (NaCl) and pH were analysed by the reference methods. The MIR-transmission of the investigated cheeses was measured by a Nicolet Magna 750 IR spectrophotometer in a measurement range between 4000 and 400 cm~(-1). The best results for WSN (R~2=0.80; ratio of standard deviation to root mean square error of prediction (RPD) = 2.22), NPN (R2=0.7l, RPD=1.85), pH (R~2=0.56, RPD = 1.50), NaCl (7?2=0.47; RPD=1.37) and TN (R~2=0.33; RPD= 1.11) were obtained when the spectra were subjected to the first derivation and smoothing after being subjected to maximum normalisation. It can be concluded that the MIR-transmission spectroscopy could be considered as an alternative technique for the determination of NPN and WSN of Emmental cheeses originating from different European countries. The NaCl, pH and TN can also be estimated, but with much lower precision.