Minerals play an important role in the structure and stability of casein micelles: minerals and caseins in milk are in dynamic equilibrium. Front-face synchronous fluorescence and mid-infrared spectra in combination with multivariate statistical analysis have been used to investigate, at a molecular level, the effects of added minerals (calcium, phosphate, or citrate) on mineral equilibria and casein micelle structure. Synchronous fluorescence spectra were recorded in the 250–500 nm excitation wavelength range using an offset of 80 nm between the excitation and emission monochromators for skim-milk samples fortified with 0, 3, 6, and 9 mM of calcium, phosphate, or citrate at 30 °C and 4 °C. Regarding midinfrared spectroscopy, the region located between 1700–1500 cm<sup>−1</sup>, corresponding to the amide I and II bands, and the 1500–900 cm<sup>−1</sup> region, called the fingerprint region, were considered for the characterization of the fortified skim-milk samples at the two considered temperatures. Principal component analysis (PCA) was applied to the collections of fluorescence and infrared spectral data of the two systems to optimize their description. The results show that the phenomena induced by the addition of phosphate were different from the ones observed following the addition of calcium or citrate, a calcium-chelating agent. Finally, common components and specific weights analysis was applied to infrared spectra and fluorescence data collected on fortified skim-milk samples. This analysis enabled the relationship between the different data tables to be established.

PDF Article

Cited By

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
Login to access OSA Member Subscription