| heal.abstract |
Two groups of kasseri cheese (pasta filata type) were manufactured from raw or pasteurized ewes' milk, without starter cultures. Cheeses of each group were divided into two subgroups: the first was ripened and stored at 4°C and packaged in plastic film; the second ripened and stored at 15°C and coated with paraffin wax. Milk pasteurization and technological parameters had a significant effect on the pH (P<0.05), while only technological parameters had an effect on the total solids content. At day 120, the range of mean cfu/g counts for the mesophilic aerobic flora was 9.5 × 107-1.4 × 108; for the thermophilic streptococci, the range was 2.6 × 107-7.6 × 107; and for the thermophilic bacilli, 9.8 × 106-1.7 × 107. Changes in the N fractions became significant after 30 days of ripening. For mature 120-day-old cheeses, the percentage of total N soluble at pH 4.6 was 22.7%-22.9% in raw milk cheeses and 19.0%-21.7% in pasteurized milk cheeses. The percentage of total N soluble at 12% TCA was 10.1%-12.2% in raw milk cheeses and 7.3%-11.5% in pasteurized milk cheeses; the percentages of total N soluble at 5% PTA were 3.1%-4.0% and 2.6%-3.6%, respectively. The residual αs-casein percentages at day 120 ranged between 63% and 78% of the respective area at day 1; the residual β-casein ranged between 67% and 75%. There were some characteristic differences in the reverse phase-HPLC peptide profiles of the four cheeses. In general, the effect of the different ripening conditions was more pronounced in cheeses made from pasteurized milk. © 2001 Society of Dairy Technology. |
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