Skip to Main content Skip to Navigation
Journal articles

Investigation of secondary structure evolution of micellar casein powder upon aging by FTIR and SRCD: Consequences on solubility

Abstract : Background Synchrotron Radiation Circular Dichroism (SRCD) and Fourier Transform Infrared (FTIR) spectroscopy were used to examine the conformation evolution of micellar casein (MC) powder during storage and to determine whether the spectral changes could be related to their solubility evolution. Results A loss in intensity of SRCD spectra as a function of storage time has been observed. Quantification of secondary structures revealed losses of α-helix content during storage. Moreover, a redshift of Amide I band in the FTIR spectrum was demonstrated during the storage and was interpreted as a rearrangement of the secondary structure of the protein, which is in line with the SRCD results. The qualitative results obtained by FTIR clearly support the quantitative evolution of the secondary structure obtained by the analysis of SRCD spectra. Principal component analysis (PCA) of FTIR spectra permits a good separation of samples according to the storage time. PCA shows that the evolution of secondary structures and solubility loss are closely linked. Conclusion With the quantitative data provided by SRCD spectra, it was established that, whatever the storage conditions, a unique curve exists between loss of α-helix content and loss in solubility, showing that loss of α-helix content is a marker of solubility loss for the MC powders studied.
Complete list of metadata

https://hal.inrae.fr/hal-02621245
Contributor : Migration Prodinra Connect in order to contact the contributor
Submitted on : Tuesday, May 26, 2020 - 1:33:12 AM
Last modification on : Wednesday, November 17, 2021 - 2:28:24 PM

Identifiers

Citation

Sarah Nasser, Alain Hédoux, Alexandre Giuliani, Cécile Le Floch-Fouéré, Veronique Sante-Lhoutellier, et al.. Investigation of secondary structure evolution of micellar casein powder upon aging by FTIR and SRCD: Consequences on solubility. Journal of the Science of Food and Agriculture, Wiley, 2018, 98 (6), pp.2243-2250. ⟨10.1002/jsfa.8711⟩. ⟨hal-02621245⟩

Share

Metrics

Record views

47