title: Evaluation of the synergistic effects of milk proteins in a rapid viscosity analyzer.
abstract: Protein systems (PS) are routinely used by companies from Brazil and around the globe to improve the texture, yield, and palatability of processed foods. Understanding the synergistic behavior among the different protein structures of these systems during thermal treatment under the influence of pH can help to better define optimum conditions for products and processes. The interpretation of the reactions and interactions that occur simultaneously among the protein constituents of these systems as dispersions during thermal processing is still a major challenge. Here, using a rapid viscosity analyzer, we observed the rheological changes in the startup viscosities of 5 PS obtained by combining varying proportions of milk protein concentrate and whey protein concentrate under different conditions of pH (5.0, 6.5, and 7.0) and heat processing (85°C/15min and 95°C/5min). The solutions were standardized to 25% of total solids and 17% of protein. Ten analytical parameters were used to characterize each of the startup-viscosity ramps for 35 experiments conducted in a 2×3 × 5 mixed planning matrix, using principal component analysis to interpret behavioral similarities. The study showed the clear influence of pH 5.5 in the elevation of the initial temperature of the PS startup viscosity by at least 5°C, as well as the effect of different milk protein concentrate:whey protein concentrate ratios above 15:85 at pH 7.0 on the viscographic profile curves. These results suggested that the primary agent driving the changes was the synergism among the reactions and interactions of casein with whey proteins during processing. This study reinforces the importance of the rapid viscosity analyzer as an analytical tool for the simulation of industrial processes involving PS, and the use of the startup viscosity ramp as a means of interpreting the interactions of system components with respect to changes related to the treatment temperature.
authors.affiliation: Núcleo de Espectroscopia e Estrutura Molecular, Departamento de Química, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG, Brazil; Tate & Lyle Gemacom Tech, Bruno Simili, 36092-050, Juiz de Fora, MG, Brazil.
authors.forename: Rodrigo
authors.initials: R
authors.lastname: Stephani
authors.affiliation: Tate & Lyle Gemacom Tech, Bruno Simili, 36092-050, Juiz de Fora, MG, Brazil.
authors.forename: Alisson
authors.initials: A
authors.lastname: Borges de Souza
authors.affiliation: Núcleo de Espectroscopia e Estrutura Molecular, Departamento de Química, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG, Brazil.
authors.forename: Marcone Augusto
authors.initials: MA
authors.lastname: Leal de Oliveira
authors.affiliation: Department of Food Technology, Federal University of Viçosa, 36571-000, Viçosa, MG, Brazil.
authors.forename: Ítalo Tuler
authors.initials: ÍT
authors.lastname: Perrone
authors.affiliation: Department of Food Technology, Federal University of Viçosa, 36571-000, Viçosa, MG, Brazil.
authors.forename: Antônio
authors.initials: A
authors.lastname: Fernandes de Carvalho
authors.affiliation: Núcleo de Espectroscopia e Estrutura Molecular, Departamento de Química, Universidade Federal de Juiz de Fora, 36036-330, Juiz de Fora, MG, Brazil. Electronic address: luiz.oliveira@ufjf.edu.br.
authors.forename: Luiz Fernando
authors.initials: LF
authors.lastname: Cappa de Oliveira
mesh_terms: D002364:Caseins / Q000737:chemistry; D055598:Chemical Phenomena; D005504:Food Analysis; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D008894:Milk Proteins / Q000737:chemistry*; D012212:Rheology; D014783:Viscosity; D000067816:Whey Proteins / Q000737:chemistry
chemical_list: D002364:Caseins; D008894:Milk Proteins; D000067816:Whey Proteins
keywords: milk protein concentrate; principal component analysis; rapid viscosity analyzer; whey protein concentrate