مقايسه فعاليت پروتيوليتيكي كيموزين نو تركيب با دو نوع مايه پنير حيواني و ميكروبي متداول در توليد پنير سفيد ايراني

The Comparison of Proteolytic Activity of Recombinant Chymosin With Microbial and Animal Rennets in Iranian White Pickled Cheese

In this study the effects of recombinant chymosin on the proteolytic, physicochemical and sensory characteristic of Iranian white pickled cheese was compared with two other types of rennet of animal and fungi origins. For this purpose three types of rennet including recombinant chymosin (RC), animal rennet (AR) and microbial rennet (MR) were used in the production of cheese in industrial scale using equal enzyme units in identical conditions.ʹ The cheeses were then packed in 11% pasteurized brine as 250g packs. The samples were kept at 12- 14°C for the first 25 days, and they were then transferred to 4- 6° C cold room for the rest of storage time of 90 days. The water-soluble nitrogen as the index of extent of proteolysis were measured at 15 days intervals. Taste panel at the end of 90 days storage also evaluated the sensory characteristics of samples. Statistic analysis of the results showed that the cheeses made using different types of rennets were significantly different for soluble nitrogen and sensory characteristics. The amount of soluble nitrogen produced in cheeses made by MR was significantly higher than cheeses made by AR and RC. The results of sensory evaluation indicated that the cheeses produced by AR and RC were not different from each other significantly, but they were both different from cheeses produced using MR at the 1% probability level. From the flavor point of view the highest and lowest scores were given to cheese samples made by RC and MR by taste panel, respectively. At last, it was known that recombinant chymosin has favorite functional properties like animal rennet and using it in Iranian cheese was recommended.