Submitted to: International Journal of Dairy Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/9/2006
Publication Date: 1/2/2007
Citation: Tunick, M.H., Van Hekken, D.L., Call, J.E., Molina-Corral, J.F., Gardea, A.A. 2007. Queso chihuahua:effects of seasonality of cheesemilk on rheology. International Journal of Dairy Technol. 60:13-21.
Interpretive Summary: The growing Hispanic-American population in the U.S. has led to a rapid increase in the consumption of Hispanic-style cheese. However, the lack of Federal Standards of Identity for these cheeses means that a given variety can have major differences from one manufacturer to the next, which is confusing to the consumer. To understand the traditional-made cheeses from Mexico from which the U.S. cheeses are based, one popular variety, Mennonite-style cheese, was studied. Samples were obtained at three different times of year and analyzed during refrigerated storage to determine their properties and how they vary with seasons and during aging. The characteristics of the cheeses made from pasteurized milk were basically the same throughout the year, but the cheeses made from raw milk showed differences because of the number of bacteria naturally occurring in the milk. All of the cheeses became softer, less cohesive, and less chewy during sixteen weeks of refrigeration. The results will allow the USDA to help define the characteristics of Mexican Mennonite-style cheese, which will enable consumers to know exactly what they are purchasing.
Technical Abstract: Fresh semi-hard raw milk (RM) and pasteurized milk (PM) cheeses made by Mennonite communities in Chihuahua, Mexico were sampled in early winter, mid-spring, and late summer and evaluated during storage to determine if rheological properties were affected by the season the cheese was produced. The rheological properties of the PM cheeses and the composition of all cheeses were consistent throughout the year. Seasonal effects were observed in the rheology of the RM cheeses, which underwent more extensive proteolysis than the PM cheeses. Summer RM cheeses exhibited the most hardness, springiness, and shear stress because of an initial elevated percentage of intact casein. Winter RM cheeses underwent the least proteolysis because of lower microbial counts. The findings indicate that the texture of RM Mexican Mennonite-style cheese is affected by the time of year, whereas the seasonal variability in texture and composition of PM cheese is minimal, allowing for the manufacture of a uniform product.