Effect of free and microencapsulated Lactococcus lactis on composition and rheological properties of Manchego-type cheeses during ripening

This study aimed at determining the composition and rheology changes during the ripening (60days) of Manchego-type cheeses prepared with Lactococcus lactis subsp. lactis and Lactococcus lactis subsp. cremoris in the free status and microencapsulated in gellan gum. The composition indicated that microencapsulation had a greater influence than the period of ripening since discrepancies were statistically significant (p<0.05) regarding the levels of protein, moisture, total solids and pH between the two cheeses both at the beginning and end of the ripening. Both cheeses presented predominantly elastic characteristics (G'>G″). The moduli and the viscosity significantly increased with the presence of microcapsules and, ripening time. Conversely, the recovery percentages on the creep curve decreased in both cheeses with an increase in ripening as a result of the degradation of proteins. The retarded time ranged between 2.32×10^-2 and 2.38×10^-2s and the J_o values were 29 times higher than the J_i values in the studied cheeses, indicating the loss of elasticity of the cheeses as they ripen.