Solid-State 31 P NMR, a Relevant Method to Evaluate the Distribution of Phosphates in Semi-hard Cheeses
- PDF / 168,250 Bytes
- 7 Pages / 595.276 x 790.866 pts Page_size
- 52 Downloads / 128 Views
Solid-State 31P NMR, a Relevant Method to Evaluate the Distribution of Phosphates in Semi-hard Cheeses Mallory Gobet & Solange Buchin & Corinne Rondeau-Mouro & Bernard Mietton & Elisabeth Guichard & Céline Moreau & Jean-Luc Le Quéré
Received: 22 October 2012 / Accepted: 20 January 2013 # Springer Science+Business Media New York 2013
Abstract The potentiality of solid-state 31P nuclear magnetic resonance (NMR) to determine in a non-destructive way the different states of phosphates in cheeses was examined. Sixteen semi-hard cheeses of various compositions were studied, and three fractions of phosphates (P) were distinguished according to their mobility: (1) mobile soluble P (ca. 10 % of total P), (2) mobile insoluble P (70 %) and (3) immobile insoluble P (20 %). In accordance with chemical M. Gobet : E. Guichard : C. Moreau : J.-L. Le Quéré (*) INRA, UMR1324, CNRS, UMR6265, Université de Bourgogne, Centre des Sciences du Goût et de l’Alimentation (CSGA), 17 Rue Sully, 21000 Dijon, France e-mail: [email protected] S. Buchin INRA, UR342 Technologie et Analyses Laitières, 39800 Poligny, France C. Rondeau-Mouro INRA, UR 1268 BIA, Plate-forme BIBS, 44300 Nantes, France B. Mietton ENILBIO, Rue de Versailles, 39800 Poligny, France Present Address: M. Gobet CNRS, UPR3079 CEMHTI, 1D avenue de la Recherche Scientifique, 45071 Orléans, France Present Address: C. Rondeau-Mouro IRSTEA, UR TERE, CS 64427, 17 avenue du Cucillé, 35044 Rennes, France Present Address: C. Moreau INRA, UR 1268 BIA, BP 71627, 44316 Nantes, France
composition and buffering capacities of the cheeses, these fractions could represent respectively (1) soluble inorganic P, (2) inorganic colloidal calcium P and phosphorylated serine residues (Pser) involved in a loose structure and (3) Pser involved in a tight environment. This method was shown to be of sufficient accuracy to evidence the effect of ripening on the different P fractions. It was thus demonstrated that solid-state NMR is an appropriate method to observe the distribution of phosphates in cheese matrix and their evolution during cheese-making. Keywords cheese
31
P NMR . Phosphate distribution . Semi-hard
Introduction Due to their presence in both soluble and insoluble fractions of dairy products, phosphates (P) are known to affect the evolution of cheeses all over the process of manufacture and ripening and to play crucial parts in the development of texture, flavour and functional properties of the final product (Lucey and Fox 1993). In the insoluble fraction, inorganic colloidal calcium phosphate (CCP) binds casein molecules through interaction with organic phosphate present as phosphorylated serine residues (Pser). Acting as a cementing agent, CCP affects the organization of casein network and thus determines the properties of the gel obtained (O’Mahony et al. 2006). In the aqueous phase, the soluble inorganic phosphate (Pi) participates to the buffering capacity of cheese, and then to the evolution of pH, which influences enzymatic activities and microbial growth, but also solubiliz
Data Loading...
