CS251723B1 - Process for the preparation of rennet by means of fungi of the class Basidiomycetes - Google Patents

Abstract

The method of preparing rennet using fungi of the Basidiomycetes class is solved by culturing fungi of the Basidiomycetes class on a nutrient medium containing 20 to 60% by weight of whey with a dry matter content of 70 to 100 mg/mL. After fermentation production of rennet, cultures of basidiomycetes of the species Ganoderma applanatum and Kuehneromyces mutabilis are preferably used. The advantage is a higher yield of rennet compared to previous methods, the absence of mycotoxins and a favorable ratio of coagulant and proteolytic activity.

Description

The invention relates to a process for the preparation of rennet by means of fungi of the Basidiomycetes class which produce coagulation enzymes.

The classic source of natural rennet is veal, resp. pork stomachs from which chymosin rennet, resp. pepsin type. Due to the lack of animal rennet preparations, the production of rennet enzymes was also studied in fungi. In particular, interest is focused on representatives of the phycoraycet of the genus Mucor, the imperfect fungi of the genus Aspergillus or the ascomycetes of the genus Endot.hia. The main advantage of these mushrooms is their relatively rapid growth. A frequent drawback of microbial rennet is higher proteolytic activity compared to animal rennine, which results in a bitter flavor and poor cheese consistency. Also, increasing evidence of the presence of mycotoxins in the cultures of these taxonomic groups of fungi provokes distrust of their use in the food industry, which is also reflected in the level of hygiene guidelines. It has also been found that a number of Basidiomycetes fungi are also capable of synthesizing milk-casein-precipitating enzymes under certain conditions. AO 188,789 /.

It is an object of the invention that the cultivation of fungi of the Basidiomycetes class is carried out on a nutrient medium containing 20 <60% by weight. whey with a dry matter content of 70 to 100 mg / raL. For fermentative production of rennet enzymes, Ganoderma applanatum III / Pers basidiomycetes cultures are preferably used. ex S.F, Gray / Donk and Kuehnerorayces mutabilis III / Schaeff. ex Fr./ Sing. et Smith, deposited in the collection of cultures of basidiomycetes MBU CSAV.

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According to the method of the invention, the yield of said enzymes is increased by 20% to 30% by weight. and using food-safe fungal species

Ganoderma applanatum and Kuehneromyces mutabilis eliminate some disadvantages (the presence of mycotoxins, the unsuitability of the ratio of clotting and proteolytic activity).

To cultivate fungal mycelial cultures, a nutrient medium is used which contains, for example, the following components (% w / w) for Ganoderma applanatum: glucose 3, corn extract 1.5, magnesium sulfate crystals. 0.15, whey / 90 mg dry matter / mL / 50, medium pH 5.5. For Kuehneromyces mutabilis, the nutrient composition (% w / w) is e.g. sucrose 3, corn extract 1.5, potassium dihydrogen phosphate 0.15, magnesium sulfate crystals. 0.05, whey / 90 mg dry matter / mL / 25, pH medium 4.0. Rennet enzymes are also produced on whey-free medium, but its addition causes higher production of clotting enzymes. The highest enzyme production was found in Ganoderma applanatum at 8 <p10. days of cultivation. At the time of maximum production, the culture medium containing the coagulation enzymes is separated from the fungal mycelium. Enzymes can be concentrated by conventional methods (ultrafiltration, lyophilization). The following is an example of a process for preparing rennet according to the invention.

Example

The fungal organism Ganoderma applanatum was cultured in a 20 L fermenter (useful volume 10 L) at 25 ° C in medium (% w / w): glucose 3, corn extract 1.5, magnesium sulfate crystals. 0.15, whey / 90 mg dry matter / mL / 50, medium pH 5.5. On day 9 of culture, the mycelium was filtered off and the filtrate was saturated with solid ammonium sulfate (662 g / L) with cooling and stirring. The precipitated proteins were collected by centrifugation, desalted by dialysis and concentrated by lyophilization. The enzyme preparation thus obtained can be stored in the refrigerator for a long time without changing rennet activity.

Claims (2)

Process for the preparation of rennet using Basidioraycetes fungi, characterized in that the cultivation of Basidioromycetes fungi is carried out on a nutrient medium containing 20% by weight of 60% by weight. whey with a dry matter content of 70 ez 100 mg / mL. 2. A process for the preparation of rennet according to claim 1, characterized in that the cultures of basidiomycetes of the species Ganoderma applanatum and Kuehneromyces mutabilis are preferably used for the fermentation production of rennet.