15C-31 |
The effects of phospholipases on Mozzarella cheese |
L. M. RICH and T. L. Sorensen. Applied Discovery, Meat and Dairy, Novozymes, 77 Perry Chapel Church RD, PO Box 576, Franklinton, NC 27525-0576 Oiling-off can be a problem in the Mozzarella cheese industry. Acting on the phospholipid found in the fat globule membrane of milk, phospholipases can hydrolyze the fatty acids in position 1 and/or 2. The rearrangement of components in the fat globule membrane could act to strengthen protein-fat interactions in the cheese matrix. The objective of this study was to use phospholipases in Mozzarella cheese to decrease oiling-off without affecting the meltability of the cheese. Cream was treated with phospholipase and standardized to 3.5% lipid using skim milk. Standardized cheesemilk was equilibrated to 35C and culture was added. Cheesemilk was rennetted at a pH of 6.4 and then allowed to set. The curd was cut and then cooked at 41C. At pH 5.3, the cheese was stretched. After stretching, the cheese was cooled and refrigerated overnight. Cheese was shredded in a blender for 20 seconds. Three grams of the shredded cheese was then molded into a metal ring (2.2 cm), placed in the center of a Whatman #4 filter paper, and heated in an oven at 90C for 5 minutes. Image Analysis was used to calculate the difference in the areas between the ring of oil and the circle of cheese. Cheese prepared as above, was placed in the center of a glass petri dish and heated in an oven at 100C for 14 minutes. Image Analysis was used to calculate the difference in the areas before and after melting. None of the added phospholipases affected the composition of the cheese (P>0.05). However, one A-2 type phospholipase and one A-1 type phospholipase significantly decreased oiling-off without affecting meltability (P<0.05). Another A-1 type phospholipase had detrimental effects on the structure of the cheese due to an uncontrollable drop in pH caused by release of fatty acids. Oiling-off can be decreased in Mozzarella cheese without affecting meltability or cheese composition using phospholipases.
Session 15C, Dairy Foods
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