|Van Hekken, Diane|
Submitted to: International Journal of Dairy Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/19/2007
Publication Date: 1/25/2008
Citation: Tunick, M.H., Van Hekken, D.L., Corral, F.J., Tomasula, P.M., Call, J.E., Luchansky, J.B., Gardea, A.A. 2008. Queso Chihuahua: Manufacturing Procedures, Composition, Protein Profiles, and Microbiology. International Journal of Dairy Technology. 61(1):62-69. Interpretive Summary: An investigation of fresh (<10 d old) Mexican Mennonite-style cheese, which is popular in Mexico and the southwestern U.S., was undertaken to determine the impact of cheesemaking parameters such as cook temperature and whey drainage on composition and protein breakdown. Results showed that the moisture in the cheese increased as the cooking temperature was decreased, and the most common proteins in cheese, caseins, were degraded more when the time used to drain the whey was lowered. Moisture content and protein breakdown are important factors in the texture and shelf life of cheese. There were no pathogens found in the product, but the microbial counts were relatively high. High-quality Mexican Mennonite-style cheese can be made by paying attention to sanitation and optimizing the method used to make the cheese.
Technical Abstract: An investigation of fresh (<10 d old) Mexican Mennonite-style cheese, which is popular in Mexico and the southwestern U.S., was undertaken to determine the impact of cheesemaking parameters such as cook temperature and whey drainage on composition and protein breakdown. Variations in the make procedure of this variety resulted in differences in moisture content and levels of intact casein (CN) and CN fragments. Moisture and moisture in nonfat substance were inversely correlated with cooking temperature. The amount of alpha-s1-CN correlated inversely with time required for whey drainage, which correlated directly with the percentages of alpha-s1-CN (f24-199) and CN fragments between 18.5 kDa and 20.0 kDa. Proteolysis of alpha-s1-CN increased with whey drainage time, and there was also evidence of beta-CN breakdown. Listeria monocytogenes, Escherichia coli O157:H7, Campylobacter spp., and Staphylococcus enterotoxin were not detected in any of the cheeses. Total aerobic and anaerobic plate counts ranged from 3 to 8 log cfu/g for pasteurized milk cheeses and 7 to 9 log cfu/g for raw milk cheeses. Proper control of make procedure and microflora will eliminate variations in quality of Mexican Mennonite-style cheese.