Changes of proteolytic and lipolytic activities during ripening of Gouda cheese prepared with fungal rennet substitute

The objective of the present study was to produce locally a suitable microb ial rennet, using the agro-industrial byproducts available in Egypt. This w ould help to meet the demands of the local cheese industry as a substitute for the rather expensive calf rennet. The calf rennet was used to manufactu re Gouda cheese as a control (TI)., Two fungal rennet preparations were use d at 2 levers for the same type of cheese (TII, TIII). The cheese was ripen ed for 3-6 weeks at 12-14 degreesC and 80-85% relative humidity. The contro ls as well as the samples of different treatments: were analyzed concerning chemical composition, proteolysis, lipolysis and sensoric properties when fresh and after 3 and 6 weeks of aging. The composition of Gouda cheese mad e with fun gal calf rennet was corn parable to a great extent to that produ ced by calf rennet alone. Proteolysis (fractions of nitrogenous compounds) and lipolysis, estimated as free fatty acids (FFA) had higher values in com parison to the control cheese. The flavour was of highest quality in Gouda cheese compared with the controls when fungal rennet and calf rennet were u sed in an equal mixture (1:1).