Multidimensional analysis of denatured milk proteins by hydrophobic interaction chromatography coupled to a dynamic surface tension detector

Distinction of different heat-treated bovine milks by native-PAGE fingerprinting of their whey proteins

“…A list of methods has been reported in the literature for the determination of whey protein fractions: (1) electrophoretic techniques using polyacrylamide gels with urea or sodium dodecylsulfate (SDS) and two-dimensional techniques (Lindmark-Månsson, Timgren, Aldén, & Paulsson, 2005;Veloso, Teixeira, Peres, Mendonca, & Ferreira, 2004); (2) high-performance liquid chromatography by ion-exchange, hydrophobic interaction, gel filtration and reversed-phase modes (Bramanti et al, 2004;Lozano, Giraldo, & Romero, 2008;Wedholm et al, 2006); and (3) immunological methods (Chen, Huang, Liu, Li, & Mao, 2004), capillary electrophoreses (Heck et al, 2008;Rehder & McGown, 2001) and electrospray ionization mass spectrometry (Losito et al, 2007). Methods based on immunological and electrophoretic techniques have been proposed to be the most accurate and sensitive techniques (Kaminarides & Koukiassa, 2002).…”

Chemical analysis in a drop: a dynamic surface tension detector for polymer and protein characterization

“…The DSTD has been successfully applied to the characterization of proteins both in FIA and in HPLC experiments, which included size exclusion and hydrophobic interaction separation mechanisms. A hydrophobic interaction chromatography (HIC) column with a denaturing agent in the mobile phase (3.0 mol L −1 guanidine hydrochloride), hyphenated with a UV absorbance detector in conjunction with a DSTD, was employed for the selective analysis of surface‐active casein fractions (α s1‐ and β‐casein) in a commercial casein mixture, raw milk samples (containing cow, ewe and goat milk) and other dairy products (yogurt, stracchino, mozzarella, parmesan cheese and chocolate cream) . In that report the denaturing agent had the dual role of readily solubilizing raw samples prior to and during chromatographic analysis and simultaneously enhancing the surface activity of several proteins which improved detection.…”

“…concentration and retention time), the selective nature of the DSTD provides the identification and concentration of surface‐active proteins in complex real matrices. The concentration can be established on the basis of calibration curves . This represents a potentially useful approach for quality control in all steps of food processing, in the pharmaceutical industry, as well as in environmental chemistry.…”

“…Note that a decrease in the surface tension of the aqueous solution due to the presence of a surface‐active analyte is quantified as an increase in the surface pressure. The on‐line calibration procedure (Eqn ) is illustrated in detail in many publications . It can be demonstrated that this calibration procedure allows compounds to be analyzed in a mobile phase characterized by a variable composition during the analysis, while the standard can be run in water .…”

Ανάπτυξη Και Μελέτη Ανακατεργασμένων Τυριών Τυρογάλακτος

“…Το αυξημένο ενδιαφέρον της παγκόσμιας βιομηχανίας τροφίμων για την αξιοποίηση των πρωτεϊνών ορού οφείλεται στο ότι αυτές εκτιμώνται ως ισορροπημένη πηγή πρωτεϊνών υψηλής πεπτικότητας και μειωμένης θερμιδικής αξίας (Scherze & Muschiolik, 2001). Οι κύριες πρωτεΐνες ορού (α-γαλακταλβουμίνη και βγαλακτογλοβουλίνη) έχουν πολύ διαφορετικές ιδιότητες και λειτουργικότητα από τις καζεΐνες (Bramanti et al, 2004). Επομένως, τα ανακατεργασμένα προϊόντα με βάση τη Μυζήθρα θα έχουν διαφορετικά χαρακτηριστικά από τα συμβατικά ανακατεργασμένα τυριά.…”