BG99311A - Ferments for bulgarian yoghourt and method for their preparation - Google Patents

Abstract

Yeasts can also be used to produce other lactic acid products, including those of non-dairy substrates. They shall at least consist of one strain from the Lactobacillus delbruecki group and subsp. bulgaricus and / or at least one strain from the group Streptococcus salivarius subsp. thermophilus, which are authentic crops, isolated from the geographical regions of Bulgaria with the traditional production of Bulgarian yogurt in the form of mixed or symbiotic or monocultures. The invention also relates to a method for the production of yeast by which receive monocultures and mixed or symbiotic yeast in DVS form. DVS the molds are suitable for production sourcing and direct application for production of Bulgarian yoghurt in industrial and domestic conditions of other lactic acid products, including those of non-lactic products substrates.

Description

BULGARIAN YELLOW MILK BAKES AND THE METHOD OF PREPARING THEM

TECHNICAL FIELD

The invention relates to the field of production of yeasts intended for the production of Bulgarian yoghurt and lactic acid products, including those of non-dairy substrates.

BACKGROUND OF THE INVENTION

Symbiotic yeast is known for Bulgarian yogurt (1), consisting of the strain Lactobacillus bulgaricus selected from the group of strains Lactobacillus bulgaricus NN 5,26,37 or 144 and strain Streptococcus thermophilus selected from the group Streptococcus thermophilus NN,1,1 and 22, in a ratio of 1: 3 to 1:10.

Specifically, yeasts described are described, consisting of:

L.b.N 5 + S.tN 12, Lb.N 37 + S.t.N 12,

Lb. 26 + S.t. 12.

L.b.N 5 + S.tN 22, Lb. N 37 + S.tN 18,

Lb.N 144 + S.tN 12, Lb.N 144+ S.tN 14,

The method of preparation consists of inoculating sterile cow's milk with various combinations of selected strains of Lactobacillus bulgaricus and Streptococcus thermophilus, including the above strains, separating combinations with normal morphology and normal proportions, which are mixed in sterile sheep or sheep's milk. of sterile sheep and cow's milk, with subsequent transplantation for 6 months, after which combinations having stable morphological properties and a stable ratio between the number of lactobacilli cells and streptococci were used. at preparation of production yeasts. The inoculation and cultivation were carried out at 45 ° C ± 1 ⁰ C, the cultivation was carried out for 2 hours, the replanting was done daily for the first 4 months, and once a week for the next two months, the first replanting being done at a mixture of sheep's and cow's milk in a 1: 1 ratio.

-2 A symbiotic yeast (2) known to be comprised of one or more strains of Lactobacillus delbrueckii subsp. bulgarlcus NN from NBPMCC 2183,2184, 2185,2186,2187,2188,2189,2189,2190,2191 2192 and Streptococcus salivarius subsp.thermophilus strains NN 2173, 2174, 2175,2176, 2177, 2178,2179,2180,2181, 2182. According to (2), it is produced as a concentrate, combinations of the above strains being cultured on nutrient media containing 1 part filtered fermented casein hydrolyzate and 2 parts by-products, with prior neutralization of the medium to pH 6.5-7.0 and sterilization at 120 C for 20 minutes at 45 ⁰ ± 1 ⁰ C, periodic neutralization in the pH range of 5.0 to 6.5, addition of gelling agent in the amount of 0.05 to 0.2% and lyophilization. milk product is a mixture of permeate or nail with digested lactose and / or sterile obesity salted milk.

SUMMARY OF THE INVENTION

Yeast for the production of Bulgarian yoghurt is offered and can be used as yeast for the production of other lactic acid products, including those from non-dairy substrates, consisting of at least one strain selected from the group Lactobacillus delbrueckii subsp. bulgaricus

per.N NBPMC per.N NBPMC

LBB B ml 2471

LBB B 31 2481

LBB B m2 2472

LBB B 37 286

LBB IN GP14 2473

LBB B 41 2482

LBB B 5 273

LBB B 120 2483

LBB B 14

2478

LBB B 122 2484

LBB B 24 2479 LBB B129 2485 LBB B 26 285 LBB B 144 287 LBB B 28 22480 LBB B 156 2486

-3 and / or at least one strain selected from the group: Streptococcus salivarius subsp. thermophilus per.N NBPMCK per.N NBPMCC

LBB TK 2487 LBB T 18 452 LBBT8 2488 LBB T 22 453 LBB T 10 2489 LBB T 28 2492 LBBT12 450 LBB T 36 2493 LBB T 14 451 LBB T 38 2494 LBB T 16 2490 LBB T m5 2474 LBB T 17 2491 LBBTR6 2475

as a mixed or symbiotic culture or monoculture.

The strains are authentic cultures isolated from geographical regions producing traditional Bulgarian yoghurt and differentiated by their morphological, physiological and biochemical characterization characteristics according to the requirements of the Birgi 1986 identifier and in IDF Standard 146/1991 and IDF Standard 149/1991.

Preferred variants of the symbiotic yeast according to the invention are combinations of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus, given in the annexed table of NSCLCC numbers as follows:

Symbiotic L.delbr.subsp.bulgaricus S.sal.subsp.thermophilus

yeast N NBPCC N NBPCC 2484-2491 2484 2491 2482-451 2482 451 2484-453 2484 453 2480-453 2480 453 2478-2489 2478 2489 2479-2488 2479 2488 2479-2490 2479 2490 2485-2490 2485 2490 2486-453 2486 453

-4The method of obtaining mixed yeasts consists in the cultivation of monocultures from the said strains in liquid nutrient media, agar nutrient media, selection by colony morphological characteristics, selection by technological parameters of monocultures and their seeding in liquid nutrient medium I, with dry matter 5-10%, consisting of skimmed milk, whose casein and lactose are hydrolyzed and a biologically-activating additive consisting of a meat extract - preferably 1-2%, peptone - preferably 0.5-1%, a yeast extract for preferably 0.1-0.5% and cool tivation at 37-42 ° C to pH 4.6 ± 0.1,

The monocultures thus obtained from Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus can be used either as monocultures or to produce mixed starter cultures.

The method for producing symbiotic yeast consists in maintaining by replication for at least 4 months multiple combinations of strains of Lactobacillus delbrueckii subsp.bulgaricus and Streptococcus salivarius subsp. thermophilus which, when co-cultured in skimmed milk or whole milk or in said nutrient medium, have shown stable relationships within the desired range of ratio between Lactobacillus delbrueckii subsp.bulgaricus and Streptococcus salivarius subsp. thermophilus.

The method of producing a monoculture concentrate, concentrated mixed or symbiotic yeast for direct application (DVS) consists of inoculation with 3-8% of the respective culture ** of culture medium II, consisting of reconstituted dry whey and buffer-activating mixture, representing an aqueous solution of: CH ₃ COONa - preferably 5-10%, CN ₂ PO ₄ - preferably 1-4%, Na ₂ HPO ₄ - preferably 1 -4%, MgSO ₄ - preferably 0.1 -0 , 5%, MnSO ₄ - preferably 0.01-0.06%, yeast extract - preferably 0.1-0.5%; or in culture medium III consisting of reconstituted skimmed milk powder and a buffer-activating mixture representing an aqueous solution of: CH ₃ COONa - preferably 5-10%, KN ₂ PO ₄ - preferably 1-4%, Na ₂ HPO ₄ is preferably 1-4%, MgSO _{4 is} preferably 0.1-0.5%, MnSO ₄ is preferably 0.01-0.06%, yeast extract is preferably 0.1-0.5% and lactose and protein concentrate obtained by ultrafiltration - preferably 0.5-4%, the fermentation process in culture medium II or III lasting 4-5 hours,

-5 after which the concentrated culture thus obtained is mixed with a protection medium and equilibration is carried out at 15-20 ° C. The protection medium is a sterile aqueous solution of sucrose, sodium glutamate and vitamin C or PEO (mol. 400 or 1000). The concentrated culture thus prepared is frozen at -65 to -80 ° C or -196 ° C or lyophilized.

The advantages of the strains according to the invention are that they allow the use of mixed starters representing different combinations of at least one strain selected from the group Lactobacillus delbrueckii subsp. bulgaricus according to the invention and at least one strain selected from the group Streptococcus salivarius subsp. thermophilus according to the invention in desirable proportions leading to an essentially lactic acid product, but with known differences in its properties according to different taste preferences or particular conditions of production and storage.

Another advantage of the strains according to the invention is that the symbiotic starters obtained with them retain the desired ratio between Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus with at least 4 months of daily subsidence in a nutrient medium I. A standardized, by quality indicators, yeast is obtained.

The method and the nutrient media according to the invention make it possible to obtain monocultures, mixed or symbiotic starters as a DVS form, whereby the process is significantly reduced in comparison with the known method of producing concentrated starters.

The resulting DVS cultures (mono- or mixed or symbiotic) are suitable for the production of yeast production and for direct application for the production of Bulgarian yogurt in industrial and domestic conditions, as well as for the production of other lactic acid products, including those from non-dairy substrates.

-6 EXAMPLES OF THE INVENTION

EXAMPLE 1. Preparation of mixed yeast

Pure crops from Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus incubated for 16 hours at 37 ° C in liquid culture medium (MRS or M17) were seeded in solid culture medium (MRS or M17) in the amount required to produce single colonies. They were incubated for 48 hours at 37 ° C. Colonies with characteristic morphology were selected and plated in liquid culture medium. They were incubated for 18 hours at 37 ° C. With 5 l of the obtained laboratory culture, medium I, 100 l, was inoculated.

W skimmed milk, whose casein and lactose are hydrolyzed, meat extract -100 g, peptone - 50 g, yeast extract - South and water to a solids content of 8%, neutralized with ammonia to pH-6.5 incubated at 42 ° C to pH 4.6.

Achieved in the number of microorganisms from 10 ⁷ to R ⁸ cfu / ml of strain Lactobacillus delbrueckii subsp. bulgaricus and 10 ⁸ to 10 ⁹ cfu / ml for strains of Streptococcus salivarius subsp. thermophilus.

The monocultures thus obtained from said strains of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus salivarius subsp. thermophilus are used to make mixed sourdoughs for Bulgarian yogurt, combining in a ratio of 1: 1 to 1:15.

EXAMPLE 2.

100 l of reconstituted dry whey (6% dry matter) and 2.5 l of buffer-activating mixture representing an aqueous solution of CH ₃ COONa 10%, KN ₂ PO ₄ - 4%, Na ₂ HPO ₄ -4%, MgSO ₄ - 0.2%, MnSO ₄ -0.04% and yeast extract 0.2%. Heat at 115 ° C for 10 min.

The medium was cooled to 45 ° C and inoculated with 5 l of refreshed laboratory symbiotic yeast consisting of Lactobacillus delbrueckii subsp. bulgaricus per.N of NBPMC 2480 and

-7Streptococcus salivarius subsp. thermophilus NBPMC N 453. Incubate in a fermentor at 43 ° C for 4 - 5 hours at pH

5.5 - 6.0 with automatic pH and temperature control. The resulting concentrated yeast was cooled to 4 ° C, mixed with 10l of protective medium, representing a sterile aqueous solution of 10% sucrose, 2% sodium glutamate and 0.1% vitamin C, and lyophilized. In another embodiment, a PEO protection medium is used in an amount of 1% aqueous solution of PEO-400 or PEO-1000.

EXAMPLE 3

'*** 100 l reconstituted skimmed milk powder (6% dry matter) and 2.5 l buffer-activating mixture representing an aqueous solution of 4% lactose, 1% protein concentrate, 10% CH ₃ COONa, 4% CN ₂ PO ₄ , 4% Na ₂ HPO ₄ , 0.2% MgSO ₄ , 0.4% MnSO ₄ and 0.2% yeast extract, thermalized at 115 ° C for 10 min. Cool to 45 ° C and inoculate with 5 l of laboratory symbiotic yeast consisting of Lactobacillus delbrueckii subsp. bulgaricus per.N of NBPMC 2482 and Streptococcus salivarius subsp. thermophilus NBPCC per.N 451 or with other symbiotic cultures according to the invention. The cultivation and preparation of the concentrated symbiotic culture was continued as described in Example 2.

EXAMPLE 4.

100 l of culture medium consisting of reconstituted dry whey and 2.5% buffer-activating mixture as in Example 3 was treated according to the procedure described in Example 2. Inoculate with 5 l of the refreshed monoculture Streptococcus salivarius subsp. thermophilus NBMPCC N 2491. Incubation is continued for 6-7 hours at 42 ° C and pH 5.7-6.0 under automatic pH and temperature control. The concentrated and cooled monoculture was mixed with 10 l of protection medium as in Example 2 and lyophilized.

-8 EXAMPLE 5

100 l of the culture medium as in Example 2 or 3 and treated according to the procedure described in Example 2 were inoculated with 5 l of the refreshed monoculture from Lactobacillus delbrueckii subsp. bulgaricus - NBPCC N 2479. The procedure was continued analogously to Example 4.

EXAMPLE 6

Lyophilized concentrated culture from Lactobacillus delbrueckii subsp. bulgaricus NBPCC N 2484 prepared according to Example 5 and Streptococcus salivarius subsp. thermophilus NBMPCC N 2491 prepared according to Example 4 were mixed in a ratio of 1: 1 to 1: 5 and used as DVS leaven.

By analogy to the above examples, other strains of the two species according to the invention produce monocultures or mixed, including multilayered or symbiotic yeasts in liquid, frozen or lyophilized form.

According to the invention, the original Bulgarian yoghurt, fresh or reconstituted dry sheep, cows, buffalo and others, can be produced according to the invention. milk, as well as a wide range of lactic acid products, including non-dairy substrates such as soybean flour, oatmeal, etc.

DVS yeasts can be used to obtain production yeasts or for direct application for the production of Bulgarian yoghurt and other lactic acid products.

CITED DOCUMENTS

1. U.S. Patent, Kondratenko et al., No. 4 156,019

2. Bulgarian Patent No 60 134

Claims (8)

Patent Claims 1.3Aquas for Bulgarian yoghurt and lactic acid products containing strains of the species Lactobacillus bulgaricus and Streptococcus thermophilus, characterized in that it consists of at least one strain selected from the group Lactobacillus delbrueckii subsp. bulgaricus per.N NBPMCK per.N NBPMCC LBB In ml 2471 LBB B 31 2481 LBB In m2 2472 LBB B 37 286 LBB B m14 2473 LBB B 41 2482 LBB B 5 273 LBB B 120 2483 LBB B 14 2478 LBB B 122 2484 LBB B 24 2479 LBB B 129 2485 LBB B 26 285 LBB B 144 287 LBB B 28 22480 LBB B 156 2486 and / or at least one strain selected from the group: Streptococcus salivarius subsp. thermophilus per.N NBPMCK per.N NBPMCC LBB TK 2487 LBB Τ 18 452 LBBT8 2488 LBB Τ 22 453 LBB Τ 10 2489 LBB Τ 28 2492 LBB Τ 12 450 LBB Τ 36 2493 LBB Τ 14 451 LBB Τ 38 2494 LBB Τ 16 2490 LBB T m5 2474 LBB Τ 17 2491 LBB T R6 2475 as a mixed or symbiotic culture or monoculture. A method for producing monocultures or mixed starters according to claim 1, which comprises cultivating monocultures of the strains of claim 1 representing authentic cultures isolated from Bulgarian yogurt, in a liquid medium, in a solid nutrient medium, selected by morphological characteristics of colonies, their sowing in sterile skimmed milk, selection by technological parameters, characterized in that the so selected monocultures are sown in liquid nutrient medium / I /, consisting of skimmed milk, whose casein and lactose are hydrolyzed, mesopeptone broth, water and biologically activating additive selected according to the type of lactic acid microorganism, followed by cultivation at 42 ° C to pH 4.6 + 0.1. 3. A method for producing symbiotic yeast according to claim 1, characterized in that they are selected by repeated transplantation in culture medium I, for at least 4 months, of combinations of Lactobacillus delbrueckii subsp strains. bulgaricus and Streptococcus salivarius subsp. thermophilus with normal morphology in a ratio of 1: 1 to 1: 5. A method of producing concentrated mixed or symbiotic yeast or monoculture for direct administration (DVS) according to claim 1, characterized in that it consists of inoculation with the respective culture medium II, consisting of reconstituted dry whey and buffer-activating mixture representing an aqueous solution of CH ₃ COONa, CN ₂ PO ₄ Na ₂ HPO ₄ , MgSO ₄ MnSO ₄ and yeast extract and fermentation at 43-45 ° C for 4-5 hours at pH 5.5-6, cooling to 4-6 ° C, after which the resultant concentrated culture was mixed with prot reducing, medium consisting of sucrose, sodium glutamate and vitamin C or PEO-400 and PEO-YUOO and frozen at -65 to -80 ° C or -196 ° C or lyophilized. 5. A method of producing concentrated mixed or symbiotic yeast or monoculture for direct application according to claim 1, characterized in that it comprises inoculation with a corresponding culture medium III consisting of reconstituted skimmed milk powder and buffer-activating agent. a mixture consisting of an aqueous solution of lactose and a protein concentrate obtained by ultrafiltration, CH ₃ COONa, CN ₂ PO ₄ , Na ₂ HPO ₄ , MgSO ₄ , MnSO ₄ and yeast extract, cultured in a fermenter at 43 - 45 ° C 4-5 hours at pH 5.5-6, cooling to 4 -6 ° C, after which the resulting concentrated culture is mixed with a protective medium consisting of sucrose, sodium glutamate and vitamin C or PEO-400 or PE0-1000 and frozen at -65 to -80 ° C or at -196 ° With or lyophilized. A method of producing monocultures or mixed yeasts according to claim 2, characterized in that the sowing is carried out in nutrient medium I with a dry matter of 5-10%, consisting of skimmed milk, the casein and lactose of which are hydrolyzed and biologically activating additive consisting of meat extract - preferably 1-2%, peptone - preferably 0.5-1%, yeast extract - preferably 0.1-0.5% 7. A method for producing concentrated mixed or symbiotic yeast or monoculture according to claim 4, characterized in that the culture medium is inoculated with culture medium II, consisting of reconstituted dry whey and buffer-activating mixture, medium II, comprising of reconstituted whey and buffer-activating mixture representing an aqueous solution of: CH ₃ COONa - preferably 5-10%, KN ₂ PO ₄ - preferably 1-4%, Na ₂ HPO ₄ - preferably 1-4%, MgSO ₄ -for preferably 0,1-0,5%, MnSO ₄ - preferably from 0.01 to 0.06%, yeast extract - for front reckoning 0.1-0.5%. A method of producing concentrated mixed or symbiotic yeast or monoculture according to claim 5, characterized in that the culture medium is inoculated with the culture medium III, consisting of reconstituted skimmed milk powder and a buffer-activating mixture representing an aqueous solution. of: CH ₃ COONa - preferably 5-10%, KN ₂ PO ₄ - preferably 1-4%, Na ₂ HPO ₄ - preferably 1-4%, MgSO ₄ - preferably 0.1-0.5%. MnSO ₄ - preferably 0.01-0.06%, yeast extract-preferably 0.1-0.5% and lactose and protein concentrate obtained by ultrafiltration-preferably 0.5-4%.