title: Molecular interactions between green tea catechins and cheese fat studied by solid-state nuclear magnetic resonance spectroscopy.
abstract: Molecular integrations between green tea catechins and milk fat globules in a cheese matrix were investigated using solid-state magic angle spinning nuclear magnetic resonance spectroscopy. Full-fat cheeses were manufactured containing free catechin or free green tea extract (GTE), and liposomal encapsulated catechin or liposomal encapsulated GTE. Molecular mobility of the carbon species in the cheeses was measured by a wide-line separation technique. The (1)H evolution frequency profile of the (13)C peak at 16ppm obtained for the control cheese and cheeses containing encapsulated polyphenols (catechin or GTE) were similar, however, the spectrum was narrower for cheeses containing free polyphenols. Differences in spectral width indicates changes in the molecular mobility of --CH3- or -C-C-PO4- species through hydrophobic and/or cation-π associations between green tea catechins and cheese fat components. However, the similar spectral profile suggests that encapsulation protects cheese fat from interaction with catechins.
authors.affiliation: Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand; Riddet Institute, Private Bag 11 222, Palmerston North 4442, New Zealand. Electronic address: ali.rashidinejad@otago.ac.nz.
authors.forename: Ali
authors.initials: A
authors.lastname: Rashidinejad
authors.affiliation: Department of Food Science, University of Otago, PO Box 56, Dunedin 9054, New Zealand.
authors.forename: Edward J
authors.initials: EJ
authors.lastname: Birch
authors.affiliation: Massey Institute of Food Science and Technology, Private Bag 11 222, Palmerston North 4442, New Zealand.
authors.forename: Jason
authors.initials: J
authors.lastname: Hindmarsh
authors.affiliation: Riddet Institute, Private Bag 11 222, Palmerston North 4442, New Zealand.
authors.forename: David W
authors.initials: DW
authors.lastname: Everett
mesh_terms: D066241:Carbon-13 Magnetic Resonance Spectroscopy; D002392:Catechin / Q000737:chemistry*; D002611:Cheese / Q000032:analysis*; D006017:Glycolipids / Q000737:chemistry; D006023:Glycoproteins / Q000737:chemistry; D066292:Lipid Droplets; D008968:Molecular Conformation; D010936:Plant Extracts / Q000737:chemistry; D013662:Tea / Q000737:chemistry*
chemical_list: D006017:Glycolipids; D006023:Glycoproteins; D010936:Plant Extracts; D013662:Tea; C110367:milk fat globule; D002392:Catechin
keywords: Full-fat cheese; Green tea catechins; Hydrophobic interactions; Liposomal nanoencapsulation; Solid-state high resolution nuclear magnetic resonance