Stručni rad
Coagulants production by fermentation and theirs application in cheesemaking process
C. Repelius
; Gist-brocades B.V., Netherlands
Sažetak
An important step in cheesemaking is the coagulation of the milk. This coagulation process is initiated by adding a coagulant to the cheesemilk. Gist Brocades, world leading company in fermentation derived coagulants, offers a broad range of coagulants: calf rennet (Delvoren®), microbial rennet (Fromase®) and the 100% chymosin product called Maxiren®. Due to an increasing cheeseproduction world-wide, calf rennet has become scarce and the need for alternative coagulants became already evident in the early sixties. Ever since, many alternative rennets have been proposed, but only a few were found to be suitable for the production of high quality cheese. The so called microbial rennets like Fromase® are the "chymosin-like" enzymes, which belong to the same class of proteases (acid proteinases or aspartate proteinases) and even the amino-acid sequence and tertiary structure have many similarities with chymosin.Despite these similarities in structure, these microbial rennets exhibit quite different properties when used in actual cheesemaking. These differences are due to the level of non-specific proteolytic activity in the product. It is therefor important that microbial rennet has a low non-specific proteolytic activity. The products from Rhizomucor miehei (Fromase®) are however very close to the properties of a good quality animal rennet and have therefor obtained by far the biggest market share of the microbial rennet products. It is because of the improvements in fermentation technology that earlier reported disadvantages of microbial coagulants have now been overcome. A high quality calf rennet (80-90% chymosin) has however remained the reference rennet against which alternative coagulants will always be compared. Modern biotechnology has now opened ways to produce pure chymosin by way of fermentation. The chymosin gen is cloned into an organism (the dairy yeast: Kluyveromyces lactis) which can then produce the enzyme in unlimited quantities. This 100% chymosin, under the Gb-brand name Maxiren®, has proved itself as the optimal coagulant with the advantages of: optimal flavour development in mature cheeses, improved gel-firming rate, optimal yield, less sensitivity to the pH of the cheesemilk, reduced dosage rate and inexhaustible supply.
Ključne riječi
chymosin; Kluyveromyces lactis; Emmental; Maxiren
Hrčak ID:
94844
URI
Datum izdavanja:
2.12.1998.
Posjeta: 3.203 *