The objective was to study the effect of two fungal lipases (Palatase 200 from Mucor miehei and Palatase 750L from Aspergillus niger), alone and combined with a fungal protease from Aspergillus oryzae (MKC fungal protease), and a bacterial neutral protease from Bacillus subtilis (Neutrase) on the maturation of Manchego type cheese to determine the practical application of these enzymes in cheese manufacture. The addition of both lipases, alone or in combination with the proteases, increased lipolysis. The M. miehei lipase affected mainly the longchain fatty acids of cheese, and the A. niger lipase affected the short- and long-chain fatty acids equally. The B. subtilis protease preparation increased lipolysis significantly, either by contamination of the enzymatic solution or by a synergetic effect with the added A. niger lipase. The protease from A. oryzae had the opposite effect on lipolysis, significantly decreasing the release of fatty acids by either partial proteolytic digestion or inhibition of the lipase. The combination of proteases and lipases increased proteolysis as measured by indexes of soluble N and HPLC of free amino acids. The PAGE of the casein fractions showed the intense breakdown of ß-caseins but not of ¿s-caseins. The exclusive addition of lipases decreased proteolysis. Sensory analysis showed a slight but significant acceleration of ripening (16%) for the cheeses treated with A. niger lipase at the beginning of aging. The M. miehei lipase induced the appearance of soapy flavor in the cheeses because of the excessive release of long-chain fatty acids. The cheeses containing the B. subtilis protease developed bitterness and sticky and crumbly texture because of the intense breakdown of ß-casein.

This work was financially supported by Research Project ALI910784 from the Comisión Interministerial de Ciencia y Tecnología.

Peer Reviewed