Use of Enzyme Extract from Lactobacillus casei, Aspergillus niger & Aspergillus oryzae for Production of Enzyme-Modified Cheese

The demand for cheese flavours has increased due to consumer request for convenience food that possesses cheese flavour. The best method for producing economic and consistent cheese flavours is through enzyme-modified cheeses production. The aim of this study was to produce enzyme extracts from Lactobacillus casei, Aspergillus niger and Aspergillus oryzae and measure the activity of lipase and proteinase of the produced enzyme extracts and employ them in cheese production. Lactobacillus casei, Aspergillus oryzae and Aspergillus niger are three kinds of microorganisms that were used in this study for the production of EMC. Solid state fermentation has been used for the production of lipolytic and proteolytic enzymes to preparation enzyme from molds and cells of L.casei were disintegrated by sonication and Lysozyme. In order to produce EMC, cheese-slurry was provided and incubated at 37ºC for 48h with crude enzyme and then assessment of proteolysis and lipolysis in the EMCs were investigated. The results indicated that L.casei has lipase and protease enzyme activities of about 103 and 80U/ml respectively, while the lipase enzyme activities was about 240 U/ml for A.niger and protease enzyme activities was about 155U/ml for A.oryzae. Assessment of proteolysis and lipolysis in the EMCs were investigated by the determination of soluble nitrogen ,tricholoracetic acid soluble nitrogen, total free amino acids and GC. The greatest levels of proteolysis and lipolysis were observed in the EMC3. No statistical difference was observed between the overall acceptability of EMC3 and commercial Cheddar cheese as
judged by the sensory evaluation panel members. The results of this research showed that the mixture of enzyme extract can be very effective on proteolysis and lipolysis in Iranian white cheese and also they can be used to produce EMC in much shorter ripening period and with improved flavor.