Submitted to: Milchwissenschaft
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 29, 2011
Publication Date: January 3, 2012
Citation: Guo, L., Van Hekken, D.L., Tomasula, P.M., Tunick, M.H., Huo, G. 2012. Effect of salt on microbiology and proteolysis of Queso Fresco cheese during storage. Milchwissenschaft. 67(1):74-77. Interpretive Summary: Although salt is a widely used and effective traditional preservative and flavor enhancer, high sodium intakes in cheeses can also bring health risks (high blood pressure, heart attack, kidney disease, stroke). This has led to recommendations by many health organizations that Americans significantly decrease sodium and salt intake. Low-salt cheeses currently available in the market are limited by flavor and functionality. Queso Fresco (QF) is a high moisture and fresh Hispanic cheese that can contain as much as 3% salt. In this study, QFs were made containing different levels of salt and aged for up to 8 weeks to determine the impact of added salt on the composition, microbiology and protein breakdown. Composition had minor changes at different salt treatments. The bacteria count increased with time and with reduced salt levels while protein breakdown changed with storage but was not greatly influenced by salt level. Decreasing salt levels to 1.5% is acceptable in QF processing. The results will be useful in developing low-salt Hispanic-style cheeses with optimum quality traits.
Technical Abstract: Queso Fresco(QF) cheeses with different salt contents were made in triplicate from pasteurized, homogenized milk using a commercial procedure. Dry curds were salted at levels of 0, 0.5, 1, 1.5, 2 and 2.5% w/w; commercial QF can contain up to 3% salt. Cheese blocks were analyzed after 1, 4, and 8 wk of storage at 4 deg C for chemical and microbiological properties. At all salt levels, decreasing the salt content did not result in significant differences in moisture, fat, or protein. The pH decreased significantly only in unsalted cheese. Water activity increased significantly with time, and was inversely proportional to the salt level. Total aerobic plate counts did not exceed the recommended limit for QF when the salt concentration was at least 1%. The results indicated that decreasing NaCl level in QF to 1.5% leads to overall acceptability and will be useful in developing low-salt Hispanic-style cheeses with optimum quality traits.