Influence of Adjunct Cultures of Lactobacillus paracasei ssp. paracasei or Lactobacillus plantarum on Cheddar Cheese Ripening

Cheddar cheeses were manufactured in open vats to study the influence of adjunct cultures of mesophilic lactobacilli on proteolysis and the development of sensory characteristics during ripening. Pairs of cheeses (one control and one experimental cheese) were manufactured on consecutive days using Lactobacillus paracasei ssp. paracasei (experimental vat A) or Lactobacillus plantarum (experimental vat B) adjuncts. A duplicate cheese-making trial was carried out 1 wk later. Lactobacilli in the experimental cheeses reached maxima (108 to 109 cfu/g) after ∼2 mo and then decreased to 106 to 107 cfu/g at 6 mo. Numbers of lactobacilli in the control cheeses were lower than in the experimental cheeses until 6 mo of ripening. Thereafter, similar numbers of lactobacilli (∼106 cfu/g) were present in all cheeses until the end of the 9-mo ripening period. Assessment of primary proteolysis during ripening showed essentially no differences between the control and experimental cheeses. However, the experimental cheeses (particularly experimental cheese A) had consistently higher levels of total free amino acids than did their corresponding controls throughout ripening. Sensory analysis of the cheeses (at 3, 6, and 9 mo) showed significant differences between the control and experimental cheeses with respect to some important sensory attributes. Principal component analysis of the sensory data clearly differentiated between the aroma and flavor of control and experimental cheeses.