Metodologia da espectroscopia no infravermelho para análise dos soros provenientes da fabricação de queijos Minas padrão e prato

Abstract

The objective of this research was to evaluate the electronic equipment based on the infrared spectroscopy for measurement of whey composition from Minas padrão and prato cheeses. The results for fat, protein, and total solids using infrared instrument based on filters and using standard methods were compared by Wilcoxon test. The differences between values obtained from both analytical methods were significant (p0.05). The standard samples used for infrared equipment calibration was whey made from raw milk; however, the whey analyzed was pasteurized. Compounds formed during heating may interfere with infrared spectrum readings. The results obtained by infrared methodology were corrected by statistical methods. After this correction, the differences between values generated by infrared and standard methods were not significant (p0.05) for Minas padrão cheese whey. Thus, the equipment calibration by uncorrected data would give accurate results, although for prato cheese whey, even after the correction, the difference was significant. This whey had a water excess and a pigment that comes from the prato cheese production. The water and pigment can affect the absorption of infrared radiation by the whey constituents. Thus, for prato cheese whey, the infrared method based on filters did not provide accurate results in the experimental conditions.