title: Effect of pH on characteristics of low-moisture Mozzarella cheese during refrigerated storage.
abstract: This study evaluated the effect of cheese pH on proteolysis, calcium distribution, and functional characteristics of Mozzarella cheese. On 4 occasions, cultured low-moisture part-skim Mozzarella cheeses were obtained from a commercial producer on the day after manufacture. Cheese blocks were randomly assigned to 2 groups. One group was shredded, subdivided, and exposed to either ammonia vapor to increase the pH or HCl vapor to decrease the pH. Samples were vacuum packaged, stored at 4 degrees C, and analyzed for pH 4.6 and 12% TCA soluble nitrogen, apparent viscosity, free oil, and water-soluble calcium on days 5, 12, 22, and 40. The 2nd group was sectioned into 23-mm thick slabs and similarly exposed to either ammonia vapor to increase the pH or HCl vapor to decrease the pH. The slabs were vacuum packaged, stored at 4 degrees C, and analyzed for pH 4.6 and 12% TCA soluble nitrogen, TPA hardness, springiness and cohesiveness, and meltability on days 17, 29, and 41. Data were analyzed by ANOVA according to a spilt-plot design. Experimentally induced pH differences persisted and significantly affected TPA hardness, apparent viscosity, meltability, and water-soluble calcium throughout 40 d of storage, but did not affect soluble nitrogen changes. Thus, cheese pH affected functional characteristics and calcium distribution but did not affect proteolysis rates. Higher cheese pH resulted in a harder cheese that required longer aging to develop desirable melting characteristics, whereas cheese with lower pH developed desirable melting characteristics more quickly but had a shorter functional shelf life.
authors.affiliation: Fluminense Federal University, Niteroi, RJ, Brazil.
authors.forename: M A S
authors.initials: MA
authors.lastname: Cortez
authors.forename: M M
authors.initials: MM
authors.lastname: Furtado
authors.forename: M L
authors.initials: ML
authors.lastname: Gigante
authors.forename: P S
authors.initials: PS
authors.lastname: Kindstedt
mesh_terms: D000641:Ammonia / Q000032:analysis; D000818:Animals; D002118:Calcium / Q000032:analysis; D002151:Calorimetry; D002417:Cattle; D002611:Cheese / Q000032:analysis* / Q000382:microbiology; D005511:Food Handling; D005519:Food Preservation / Q000379:methods*; D006851:Hydrochloric Acid / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D008892:Milk; D008894:Milk Proteins / Q000032:analysis; D012034:Refrigeration; D048249:Streptococcus thermophilus; D014867:Water / Q000032:analysis
chemical_list: D008894:Milk Proteins; D014867:Water; D000641:Ammonia; D006851:Hydrochloric Acid; D002118:Calcium