Production and evaluation of enzyme-modified cheese adding protease or lipase to improve quality properties

Enzyme-modified cheese (EMC) produced by enzyme hydrolysis is a natural, cost-effective, and flexible alternative to using natural cheese in industrial applications. The modification of cheese by enzymes can increase their benefits for consumer acceptance and health, and intensify the specific cheese flavor. We evaluated the properties of cheese with added protease (Ep) or lipase (El), including texture, sensory, organic acids, volatile compounds, and free amino acids. As results, the hardness and gumminess of the cheese reached their maximum values when the concentration of protease and lipase was 0.1% and 0.6%, respectively. Interestingly, the bitterness and astringency of the cheese was reduced. The highest scores for odor, taste, and overall acceptability were observed on 0.08% protease in Ep and 0.8% lipase in El. Compared with the anchor cheese, eight new compounds were produced after the addition of protease and nine new compounds were produced after the addition of lipase. Irrespective of the type of enzyme, the content of free amino acids decreased slightly with the increase in enzyme content. From the point of view of adding enzyme species, the free amino acids content of Ep was generally higher than that of El, and glutamic acid and proline contents were high. Acetic acid concentrations (aroma-active compounds) of enzyme-modified cheese using protease and lipase were 482-931 mg/100 g and 30-36 mg/100 g, respectively, which were significantly increased. According to the results obtained in this study, a cheese with higher sensorial and textural acceptability was obtained by adding the appropriate protease or lipase.