15B-14 |
Role of calcium on dynamic rheological properties of Mozzarella cheese |
N. JOSHI1, K. Muthukumarappan, and R. I. Dave. (1) South Dakota State University, Brookings, SD 57007 Visco-elastic properties of Mozzarella cheese determine its end use, particularly as a food ingredient. Dynamic testing is fundamental to evaluate rheological characteristics of cheeses. Calcium plays an important role in deciding functional and rheological properties of Mozzarella cheese. We hypothesize that altering levels of calcium shall bring the changes in visco-elastic properties of Mozzarella cheese. The objective of this study was to evaluate effects of calcium on rheological parameters (G’ and G”) of Mozzarella cheese. We also intended to study the effect of increasing temperature during the testing on these properties. Part skim Mozzarella cheeses were made by direct acidification technique using glucono-delta-lactone. Pre-acidification of milk with a combination of citric acid and acetic acid (prior to renettting) brought difference in calcium levels (0.65, 0.48, 0.42 and 0.36 %) in the experimental cheeses. Cheeses were stored at 4° C and analyzed at 1, 7, 15 and 30 days for G’ and G”. During testing the temperature was raised from 25 to 45°C at 1-min. time interval to study the effect of temperature on these properties. The control cheese made without pre-acidification of milk (0.65 % Ca) had higher values of G’ and G” throughout the storage at all the test temperatures as compared to the experimental cheeses containing 0.48, 0.42 and 0.36 % calcium. The difference in G’ and G” among the experimental (reduced calcium) cheeses was not noticeable. With increase in the temperature of testing, reduction in the values of G’ and G” of all the cheeses was observed. On day 7, values of G’ and G” were maximum in all the cheeses. The values of G’ were always higher than G” in all the cheeses. These results are useful for the cheese industry. Manipulation of calcium levels can bring significant changes in visco-elastic behavior of Mozzarella cheese.
Session 15B, Dairy Foods: Chemistry, microbiology and sensory analysis of various cheeses
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