James A. Gilmore

Relationship between the yield of cheese (Chevre) and chemical composition of goat milk

Abstract The relationships between goat milk constituents and cheese (Chevre, a fresh goat’s milk cheese) yield were determined to develop formula for predicting the moisture-adjusted yield of Chevre. Samples of commingled goat milk shipped to a commercial manufacturer of Chevre were collected weekly over a 12-month period and analyzed for milk fat, crude protein (CP), casein, total solids (TS), and mineral contents. The yield of Chevre made from the sampled milk was measured and adjusted to a 60% moisture content. There was a definite trend in the 60% moisture-adjusted yield of Chevre during the year, which ranged from 14% in June to 20% in December and January. Milk TS and CP contents were the most significant predictors of Chevre yield ( Y ): Y=2.64 TS −15.48 ( r 2 =0.81, P Y=8.6116 CP −12.7598 ( r 2 =0.79, P

Distribution of plasminogen activator in different fractions of bovine milk

The type and relative amounts of plasminogen activator (PA) in different fractions of bovine milk obtained from 15 Holstein cows were examined. Raw milk was centrifuged to separate skim milk and a somatic cell pellet. PA was mainly localized within the casein fraction, being 42 times that in the serum, and in association with somatic cells. The predominant form of PA in milk casein was isolated from SDS-PAGE gel extracts and had a molecular mass of approximately 75 kDa. Its activity was increased 4.1-fold (P < 0.01) in the presence of fibrin but was unaffected by the presence of amiloride, indicating that it was due to tissue-PA. The predominant forms of PA associated with milk somatic cells were isolated from SDS-PAGE gel extracts and had molecular masses of approximately 30 and approximately 50 kDa. The activity of both proteins was unaffected by the presence of fibrin but was dramatically reduced by the presence of amiloride, indicating that they represented urokinase-PA.