ARS | Publication request: RHEOLOGY AND MICROSTRUCTURE OF QUESO BLANCO AS AFFFECTED BY PRESSING PROCEDURE AND STORAGE CONDITIONS

Submitted to: Milchwissenschaft
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 8, 2007
Publication Date: May 1, 2008
Citation: Tunick, M.H., Van Hekken, D.L., Cooke, P.H. 2008. Rheology and microstructure of queso blanco as afffected by pressing procedure and storage conditions. Milchwissenschaft. 63(2):157-160.

Interpretive Summary: Queso Blanco is a popular semi-soft Hispanic-style cheese that consumers can keep for weeks in a refrigerator. Queso Blanco and other cheeses are pressed to remove whey by any of several methods, including stacking in molds by hand and applying pressure, or by mechanical compacting and molding of each cheese block. The textural properties of Queso Blanco were studied to see they were affected by the method of pressing, the temperature of storage, or by periodically removing the cheese from a refrigerator. Cheeses that were pressed by stacking or by mechanical compacting were refrigerated for up to twelve weeks, with half of the samples undergoing abuse by allowing them to warm to room temperature at regular intervals. The results indicated that the texture was not affected by storage temperature, removal from the refrigerator, or by method of pressing. An electron microscope showed that the differences between the cheeses was slight. The texture of Queso Blanco will not be affected by pressing method or by storing it under conditions that are less than ideal.

Technical Abstract: Queso Blanco, a popular Hispanic-style cheese, was pressed using either a vertical press or a compression molder, and then stored under different conditions to determine if its rheological characteristics, and thus its consumer acceptance, would be affected. Texture profile analysis, torsion testing, and small amplitude oscillatory shear analyses indicated that pressing procedure, length of storage (up to 12 wk), temperature of storage (4 or 10 deg C), and temperature abuse (repeatedly allowing the cheese to reach 20 deg C) did not appreciably change the fracture, elastic, or viscous properties of the cheese. Electron microscopy showed that the microstructure of all of the cheeses consisted of a mesh of discrete curd particles and fat globules. Although the globules aggregated over time, the rheology of the cheese was unaffected by pressing method or by temperature. Queso Blanco may be stored with temperature abuse for up to 3 mo at 4-10 deg C without influencing the rheology, and therefore the quality, of the product.