ALKALINE-PHOSPHATASE, ACID-PHOSPHATASE, LACTOPEROXIDASE, AND LIPOPROTEIN-LIPASE ACTIVITIES IN INDUSTRIAL EWES MILK AND CHEESE

Alkaline phosphatase activity in raw, industrial ewe's milk increased steadily >2-fold between January [1.7 units (U)/mL] and June (3.75 U/m L), whereas acid phosphatase increased 4-fold in January and February (17 mU/mL) and then remained constant until the end of lactation. By c ontrast, lipoprotein lipase exhibited a downward trend and lactoperoxi dase decreased 2-fold during lactation. When assayed at cheese-ripenin g temperatures, acid phosphatase retained 16% of its activity at 37 de grees C, whereas lactoperoxidase retained between 30 and 45% of its ac tivity at 20 degrees C. The rate of hydrolysis of model triacylglycero ls by lipoprotein lipase was highest for tricaprylin. Although alkalin e phosphatase in raw milk cheeses was variable from 1 to 180 days of r ipening, no apparent reactivation was observed. The activity of acid p hosphatase increased 2-fold during the 180 days of ripening in the che eses made in summer, whereas in winter and spring much smaller increas es were observed. Both raw milk cheeses made in summer and all pasteur ized milk cheeses had very low levels of lactoperoxidase throughout ri pening.