Evolução das características físico-químicas e da maturação em Queijo Amarelo e Queijo Picante da Beira Baixa DOP: composição, fracções azotadas e ácidos gordos livres

Mestrado em Engenharia Alimentar - Instituto Superior de AgronomiaThis work was carried out to monitor the evolution of the physicochemical characteristics of cheese represent two of the Protected Designation of Origin (PDO) from “Beira Baixa” cheese, the Amarelo cheese and Picante cheese, produced in a plant recognized its production. This assessment was complemented by studying the evolution of some parameters characterizing the maturation. In addition to the assessment of physical and chemical characteristics of the cheese used in the definition contained in the regulations of the PDO, based on levels of fat and moisture, parameters such as acidity, pH, nitrogen fractions were considered as well as some relationships between them, as features of characterization of the cheese repening. Some parameters were also used to characterize the ripening-related metabolism of fat and lactate (acidity of the fat and free fatty acids), important aspects with regard to sensory characteristics of cheese, which are much less used in the characterization of these products, often because the complexity involved in their analytic determination. This study describes two analytical techniques (the method of salts and the method of resin) applied to the determination of free fatty acids in the “Beira Baixa” PDO (protected designation of origin) cheeses, Amarelo cheese and Picante from cheese in order to choose the best suited to achieving the best analytical results. This selection was based primarily on the recovery rates obtained for the different acids studied by two methods. The assessment of physical and chemical characteristics was also made along the ripening period in Picante Cheese and Amarelo Cheese. The samples were collected at 5, 30 and 45 days for Amarelo Cheese and at 45, 90 and 120 days for Picante cheese. Based on the results obtained during the evolution of the physicochemical characteristics and free fatty acids, the evolution of glycolysis, proteolysis and lipolysis monitored. The results showed the differences between the Amarelo cheese and Picante cheese. Considering previous date, the results suggest that the recent production technologies could generate differences on cheese propertie