Assessing the Extent of Degradation in the UV Radiation and Heat-Catalyzed Oxidized Whole Milk Powder: The UV Photoacoustic and Diffuse Reflectance Spectroscopies versus the Peroxide Value

Abstract

The extent of quality loss caused by enzymatic and nonenzymatic browning reactions in milk powders is usually assessed by the chemical methods, among which the determination of peroxide value (PV) is a widely used approach. In this paper, peroxide values obtained from deliberately oxidized (UV irradiation combined with the thermal stress) whole milk powders are compared to the results of photoacoustic spectroscopy (PAS) and diffuse reflectance spectrometry (DRS) in the ultraviolet and visible region. The same samples were also investigated by various methods in the near-infrared (NIR) region. The experimental data suggest a good degree of correlation between the PV and the PAS and DRS data collected at 335 nm.