title: Distribution and mobility of phosphates and sodium ions in cheese by solid-state 31P and double-quantum filtered 23Na NMR spectroscopy.
abstract: The feasibility of solid-state magic angle spinning (MAS) (31)P nuclear magnetic resonance (NMR) spectroscopy and (23)Na NMR spectroscopy to investigate both phosphates and Na(+) ions distribution in semi-hard cheeses in a non-destructive way was studied. Two semi-hard cheeses of known composition were made with two different salt contents. (31)P Single-pulse excitation and cross-polarization MAS experiments allowed, for the first time, the identification and quantification of soluble and insoluble phosphates in the cheeses. The presence of a relatively 'mobile' fraction of colloidal phosphates was evidenced. The detection by (23)Na single-quantum NMR experiments of all the sodium ions in the cheeses was validated. The presence of a fraction of 'bound' sodium ions was evidenced by (23)Na double-quantum filtered NMR experiments. We demonstrated that NMR is a suitable tool to investigate both phosphates and Na(+) ions distributions in cheeses. The impact of the sodium content on the various phosphorus forms distribution was discussed and results demonstrated that NMR would be an important tool for the cheese industry for the processes controls.
authors.affiliation: INRA, ENESAD, Université de Bourgogne, UMR1129 FLAVIC, F-21000 Dijon, France.
authors.forename: Mallory
authors.initials: M
authors.lastname: Gobet
authors.forename: Corinne
authors.initials: C
authors.lastname: Rondeau-Mouro
authors.forename: Solange
authors.initials: S
authors.lastname: Buchin
authors.forename: Jean-Luc
authors.initials: JL
authors.lastname: Le Quéré
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Guichard
authors.forename: Loïc
authors.initials: L
authors.lastname: Foucat
authors.forename: Céline
authors.initials: C
authors.lastname: Moreau
mesh_terms: D002611:Cheese; D007474:Ion Exchange; D007477:Ions; D009682:Magnetic Resonance Spectroscopy; D010710:Phosphates / Q000737:chemistry*; D010758:Phosphorus / Q000737:chemistry*; D011789:Quantum Theory; D012964:Sodium / Q000737:chemistry*
chemical_list: D007477:Ions; D010710:Phosphates; D010758:Phosphorus; D012964:Sodium