Effect of Ripening in Brine and Vacuum on Protein, Fatty Acid and Mineral Profiles, and Antioxidant Potential of Reduced-Fat White Cheese

Abstract

Research background. Research background. The ripening of reduced-fat white cheese is affected by numerous factors. The aim of this study is to investigate the influence of ripening environment (brine or vacuum plastic bags without brine) on the chemical composition, protein, fatty acid profiles and mineral content as well as antioxidant properties of industrially produced reduced-fat white cheese. Experimental approach. A low-fat white cheese was manufactured in an industrial scale from milk that remained after the production of kajmak and ripened for 60 days at 4 °C after packaging in a polystyrene container with brine containing 6 % salt or in vacuum-sealed polyethylene bags. The influence of ripening environment on proteolysis was monitored by the change of soluble nitrogen fractions as well as by SDS-PAGE of Tris-HCl extracts of cheese proteins under non-reducing conditions and water-soluble fractions under reducing conditions. An effect that ripening environment had on fatty acid and mineral content was also monitored. The change of antioxidant potential of investigated cheese during ripening was followed by the change of iron(II) chelating ability, reducing power and free-radical scavenging activity. Results and conclusions. The ripening environment differently affected proteolysis, fatty acid composition, mineral profiles and antioxidant properties of reduced-fat white cheese. White cheese ripened in brine had more intensive proteolytic changes than the cheese ripened in a vacuum, but also more intensive diffusion processes, especially between the 40th and 60th day of ripening. The brine ripened cheese had higher values of water-soluble nitrogen content, but lower contents of trichloroacetic acid-soluble and phosphotungstic acid-soluble nitrogen than a vacuum ripened cheese. Cheese ripened in brine had a lower content of almost all investigated macro- and microelements. After 60 days of ripening, in the cheese ripened in brine only myristic (C14:0) and palmitic acid (C16:0) were detected whereas in a vacuum ripened cheese C10:0-C16:0 fatty acids dominated. Vacuum ripened reduced-fat cheese had more favourable reducing power while white brined reduced-fat cheese had better radical scavenging activity and iron(II) chelating activity. Novelty and scientific contribution. Ripening in a vacuum becomes a useful method for obtaining high-valuable reduced-fat white cheese.