Rheological, physicochemical and authenticity assessment of Minas Frescal cheese Renata Bongiolo Magenis a , Elane Schwinden Prudêncio a , Carlise Beddin Fritzen-Freire b , Marilia Penteado Stephan c , Antônio Silvio do Egito d , Heitor Daguer e, * a Universidade Federal de Santa Catarina (UFSC), Departamento de Ciência e Tecnologia de Alimentos, Rod. Admar Gonzaga, 1346, Bairro Itacorubi, Florianópolis, 88.034-001 SC, Brazil b Instituto Federal de Santa Catarina (IFSC), Campus Xanxerê, Xanxerê, 89820-000 SC, Brazil c Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), Rio de Janeiro, 23020-470 RJ, Brazil d EMBRAPA, Sobral, 62010-970 CE, Brazil e Ministério da Agricultura, Pecuária e Abastecimento (MAPA), Laboratório Nacional Agropecuário (LANAGRO), São José, 88.102-600 SC, Brazil article info Article history: Received 27 January 2014 Received in revised form 28 March 2014 Accepted 9 April 2014 Available online 18 April 2014 Keywords: Minas Frescal cheese Rheology Color Electrophoretic profile Authenticity abstract This study was carried out to assess physicochemical (color, moisture, protein and fat content) and rheological properties (fracture stress, fracture strain, degree of solidity and stress decay), as well as to assess the authenticity (using SDS-PAGE) of Minas Frescal cheese in 21 commercial samples acquired in Southern Brazil. Large differences among the samples, which tended to present a yellowish white color were observed. Moisture and protein influenced on the rheological properties and cheeses showed a tendency to being viscous and firm. SDS-PAGE revealed a wide unexpected variability in their proteins profiles and a densitometric casein/b-lactoglobulin ratio allowed to distinguish authentic cheese from adulterated ones. The profiles suggest the irregular presence of whey in the composition of these products, contrary to the enzymatic process legally required. These results emphasize the need for a more effective control, mainly in the selection of raw material, aiming to offer consumers authentic products. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction The Minas Frescal is a genuine Brazilian cheese and it is the country’s most widely consumed cheese type (Planzer et al., 2009). It is produced mainly by small and medium-sized factories in the South and Southeast regions of Brazil. It is a fresh white cheese that has high moisture content, does not undergo maturation, is of short durability and has no preservatives (Souza, Cruz, Moura, Vieira, & Sant’Ana, 2008). This cheese is produced with pasteurized milk through enzymatic coagulation by addition of rennet and/or other appropriate clotting enzymes, whether they are complemented or not by the action of a lactic acid starter culture (Brasil, 1997). Ac- cording to Brazilian regulation, Minas Frescal cheese can be pre- sented in a cylindrical shape, weighing from 0.3 kg to 5.0 kg (Brasil, 2006). It is officially classified a semi-fat and very high moisture cheese (Brasil, 1997, 2004). In this conventional cheese-making process, the action of the clotting enzymes in milk results in the destabilization of the casein micelles. Therefore, the caseins are retained in the curd and whey proteins are expelled to the aqueous phase (whey) (Chromik, Partschefeld, Jaros, Henle, & Rohm, 2010). The production process of Minas Frescal cheese is considered relatively simple and the use of traditional equipment and no need for maturation allow producers to have a quick investment return (Furtado, 1999). However, consumers expect cheeses to be repro- ducible and consistent, with appropriate composition and quality, especially among those belonging to the same category (Fox & Cogan, 2004). Characterization of cheeses is also important for the protection of traditional diversity and for contributing to baseline data for quality control. Physicochemical and rheological methods, as well as the electrophoretic profile, are used to evaluate the quality of cheese (Brighenti, Govindasamy-Lucey, Lim, Nelson, & Lucey, 2008; Foegeding & Drake, 2007; Holland, Yazdi, Tita- piccolo, & Corredig, 2010; Pinho, Mendes, Alves, & Ferreira, 2004). Consumers and inspection authorities have been increasingly concerned about the authenticity of milk and dairy products. Bra- zilian regulation establishes a standard of identity and quality for * Corresponding author. Tel.: þ55 48 3261 9918; fax: þ55 48 3261 9921. E-mail address: heitor.daguer@agricultura.gov.br (H. Daguer). Contents lists available at ScienceDirect Food Control journal homepage: www.elsevier.com/locate/foodcont http://dx.doi.org/10.1016/j.foodcont.2014.04.012 0956-7135/Ó 2014 Elsevier Ltd. All rights reserved. Food Control 45 (2014) 22e28