Primary proteolysis and textural changes during ripening in Cheddar cheeses manufactured to different fat contents

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• 作者：Fenelon ; Mark A. ; Guinee ; Timothy P.
• 关键词：Proteolysis ; Texture ; Fat content ; Cheddar cheese
• 刊名：International Dairy Journal
• 出版年：2000
• 出版时间：March, 2000
• 年：2000
• 卷：10
• 期：3
• 页码：151-158
• 全文大小：266 K

文摘

The effects of varying fat content in Cheddar cheese, from 6.3 to 32.5g 100gp>−1p>, on changes in pH, primary proteolysis and texture were monitored over a 225d ripening period. Reduction in the fat content resulted in significant (P<0.05) increases in pH, moisture and protein contents and decreases in the concentration of moisture in the non-fat substance. The increase in pH as the fat content increased was attributed to the concomitant decrease in the lactate-to-protein ratio. Polyacrylamide gel electrophoresis showed that the concentration of intact casein decreased in all cheeses during ripening and that the rate of decrease was not affected by the fat content. However, for a given concentration of casein, α_s1-casein was degraded more slowly, and β-casein more rapidly, as the fat content was reduced. The slower degradation of α_s1-casein with decreased fat content coincided with a decrease in the ratio of residual chymosin activity to protein in the cheese. At most ripening times, reduction in the fat content resulted in significant increases in the concentration of intact casein, fracture stress, fracture strain, and cheese firmness. The effects of fat reduction on proteolysis and rheology are probably due to the interactive effects of the concomitant changes in composition.