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

Cheddar cheese made with proteinasepositive 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 proteinasepositive 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.