Proteolysis and Flavor Development in Cheddar Cheese Made Exclusively with Single Strain Proteinase-Positive or Proteinase-Negative Starters

¹ Department of Food Chemistry
² Department of Food Microbiology, National Food Biotechnology Centre, University College, Cork, Ireland

Proteolysis and flavor development in Cheddar cheese made with proteinase-positive Lactococcus lactis ssp. cremoris UC 317 or its proteinase-negative variant UC 041 were monitored during ripening. Qualitatively, electrophoretograms of the cheeses were similar throughout ripening, but electrophoretograms of water-soluble N extracts from the proteinase-negative cheeses were significantly different from those of the proteinase-positive cheeses. The levels of water-soluble N in proteinase-positive and proteinase-negative cheeses of the same age were not significantly different. However, the proteinase-positive cheese had a significantly higher level of amino N throughout ripening. Proteinase-positive cheeses received slightly higher scores for flavor and body and texture than proteinase-negative cheeses of the same age. Nevertheless, the overall quality of all the cheeses was good, suggesting that starter peptidase activity may be more important than starter proteinases in flavor development in cheese during ripening.

Key Words: starter proteinases • proteolysis • Cheddar

Submitted on July 5, 1989
Accepted on October 16, 1989