|Van Hekken, Diane|
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 5/26/2013
Publication Date: 6/10/2013
Citation: Tunick, M.H., Van Hekken, D.L. 2013. Characteristics of food using Queso Fresco cheese as an example (abstract). The First US Korea Symposium on Food and Agricultural Engineering, p.23-25.
Technical Abstract: Processing and aging affect food characteristics, such as rheology, functional properties, microstructure, and sensory traits. These effects are discussed using Queso Fresco, a popular Hispanic cheese variety, as an example. Gas chromatography-mass spectrometry data indicated that lipolysis occurred in the cheese during storage, generating volatile compounds responsible for flavor. The protein profiles obtained from electrophoresis showed that the alpha-s1-casein, the primary structural protein in cheese, decreased significantly during storage. Texture profile analyses indicated a crumbly texture. Rheological results from torsion gelometry and small amplitude oscillatory shear analysis suggested that Queso Fresco fractures easily without tolerating much twisting and that the cheese matrix was granular as opposed to a solid mass. The amount of free whey increased during storage because proteolysis caused some of the casein matrix to break down and release the whey held in it. The cheese did not melt, as expected, but color changed from bright white to light or medium brown when baked or broiled due to Maillard reactions. Queso Fresco provides a good model for showing how physical tests reveal the behavior of food, enabling scientists to determine its quality characteristics.