14A-14 |
Effects of freezing and thawing on chemical changes in plain soft and Monterey Jack goat milk cheeses |
S. J. LEE1, J. H. Lee1, A. Kalantari1, V. Gutta1, and Y. W. Park2. (1) Agricultural Research Station, Fort Valley State Univ., 1005 State University Dr., Fort Valley, GA 31030-4313, (2) Agricultural Research Program, Fort Valley State Univ., College of Agriculture, Home Economics & Allied Programs, 1005 State University Dr., Fort Valley, GA 31030-4313 Feasibility of freezing goat milk products is highly important for dairy goat industry for its survival and uniform supply of caprine products. Although impacts of freezing and thawing on shelf life of caprine cheeses are important, scanty of literature is available on this premise. The objective of the study was to assess effects of freezing and thawing on chemical changes in plain soft and Monterey Jack (MJ) goat cheeses in relation to shelf life. Soft cheeses were obtained commercially and MJ cheeses were manufactured at the University pilot plant. Three batches of both varieties were divided into two equal portions. One half was immediately stored at 4oC for 0, 14, and 28 days, and the other was immediately frozen at -20oC for 24 hr, thawed at 4oC for 24 hr, followed by identical treatment as fresh samples. All cheeses were subjected to analyzing changes in pH, acid degree value (ADV), water soluble nitrogen (WSN), and proximate analysis. Results revealed that pHs in both cheeses were not affected by freezing nor by aging at 4oC for 4 wks. The soft variety had lower pHs of 4.04-4.13 compared to pHs of 5.79-6.03 in MJ cheeses, which may be accountable for differences in manufacturing procedures. The respective %WSN in soft and MJ varieties were approximately 10 and 17 %, and were unaffected by freezing and storage times. The higher WSN in MJ was expected because of 6 wks aging before freezing experiment. Freezing also did not influence ADVs of the cheeses. Soft variety had ADVs of 0.4-0.65 with slight increases by aging time. MJ exhibited significantly higher ADVs of 1.13-1.36, probably due to the pre-aging. No apparent freezing effects were observed on chemical changes in goat cheeses, which suggest a strong feasibility of freezing goat cheeses for later marketing without deteriorating shelf life.
Session 14A, Dairy Foods: General developments in dairy technology I
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