DE4025303A1 - Prodn. of sour-dough reproducibly - using starter contg. Lactobacillus strain not producing acetate - Google Patents

Abstract

Prodn. of sourdough for mfr. of bread and other. bakery prods. from cereal flour and water is affected using a starter culture contg. a heterofermentative Lactobacillus strain yielding an acetate-free C2 prod. The Lactobacillus strain is DSM 6037 and/or 6129 (see DE 4025305). The starter culture also contains (a) an acetate-contg. additive or an acetate producing Lactobacillus strain, esp. L.brevis, L.brevis ssp lindneri, L.fermentum, L.buchneri and/or L.fructivorans; (b) a yeast, and (c) dextrose, lactose or Na glutamate. ADVANTAGE - The process gives sourdough prods. with reproducible properties.

Description

The invention relates to a method for producing a Sourdough made of cereal bread and / or flours and Water using a heterofermentative lactoba cillen containing starter culture for the preparation of Bread and baked goods.

For the production of a suitable sourdough from rye flour, different processes have been developed where the dough in several or just in one step is introduced. The multi-level tours take into account The different temperature requirements of Microorganisms in the dough and control in this way the Sourdough production.

These methods are mainly used to certain ratio of lactic acid to acetic acid, d. H. to create a certain fermentation quotient (cf. Manual sourdough, Behr's ... publishing house, 1987, S 148-161). So z. B. at a temperature of the sourdough of approx. 15 ° C reinforced acetic acid and amplified at about 28 ° C.  Lactic acid produced. It is also known the tempera as a function of the electrical conductivity of the lower the value of the good that has been set, thereby of acetic acid bacteria (German Patent DE 37 26 615 A1).

By the duration of the respective temperature levels is Influence on the amount of acid formed. It is that Skilled in the art, in one step at a low level Temperature and a certain known by experience Time to produce a certain amount of acetic acid and in the next stage by a temperature increase during lactic acid production for a certain period of time guarantee.

In addition, in the individual stages in a Überla Were carried out the yeast cell proliferation.

Such methods are reliable, but very time consuming and labor intensive.

As multi-stage methods are known, for example:

• - Foam Sour Procedure (5-step process, the especially aimed at the propagation of yeasts is);
• - 3-stage acidity:
  • a) Basic overnight (classic, empirically developed sourdough guide);
  • b) full sour overnight;
  • c) Detmolder 3-stage duration (which in case of a) and b) is unavoidable evening work);
• - Detmolder 2-stage tour:
  • a) full-acid maturity 2.5-3.5 hours;
  • b) full-sourced 3-4 hours;
• A simplification, the so-called Einstufenver drive for the production of sourdoughs. In these  become both lactic and acetic acid in one step in a wearable for the bread taste ratio (Fermentation quotient) produced. This goal is achieved through the use of breeding periods, which according to experience under the conditions of the one-step procedure useful sourdough. The disadvantage is that no purposeful influence on the fermentation quotient can.

A significant yeast multiplication does not take place in sourdough instead of. Industrial yeast must be added to the bread dough become.

As a one-step process, for example, it is known:

• - Monheimer Salzsauerverfahren;
• - Detmolder 1-stage guide;
• - Berlin Kurzsauerführung (shortest biological Säuerungsverahren);
• - Isernhäger Natursauer (salient feature is the deliberate bringing about of hyperacidity of the Sourdough, so the targeted crossing of a by experience determined acid range of the Sourdough, cf. DE-PS 26 11 972).

Instead of breeding periods can be selected for inoculation bacterial starter cultures are used, the konventio nell (by lyophilization or by spray-drying) (see European Patent Application EP 01 31 114 A2). Another starter culture is under the Designation Detmold 83 known. This is it a mixed culture of known microorganisms, namely Lactobacillus plantarum, Lactobacillus brevis var. Lindneri and Lactobacillus fructivorans (cf. Paperback for the "Application of Starter Cultures", Rudolf Müller & Co., 6301 Pohlheim, 1989, S 2-3. 10-11). Also from "ZFL" 7, 1988, pages 597 to 602 is a heterofer Lactobacilli containing starter culture known.

These starter cultures have the disadvantage that the Microorganisms in their re-seed their otherwise  advantageous propagation properties, such as education lose a certain fermentation quotient. To Two times overcrowding is another usefulness no longer guaranteed.

The above methods offer those in sourdough existing microorganisms very different Conditions. Despite the different conditions Lactic acid bacteria and yeasts are the ones in the Batter out dominant groups.

The known heterofermentative lactic acid bacteria produce a C body which always contains ethanol and acetate. Such known lactic acid bacteria are, for example, Lactobacillus reuteri (DSM 20016), Lactobacillus fermentum (DSM 20052) and Lactobacillus viridescens (DSM 20410 ).

For the use of lactobacilli in sourdough Position are the type and quantity of the educated by them Products of great importance. Only through the production Rye flour is able to bake a sufficient amount of acid.

The taste of a rye flour bread is essentially by the in the course of sourdough fermentation formed lactic acid and acetic acid. It is the Fermentation quotient of particular interest. A high one Acetic acid content of 25% of the total acid leaves the Bread tastes sour, while 85% lactic acid one produced a mild bread flavor.

The invention is generally concerned with the problem of Production of a sourdough with consistently favorable Properties.

It solves this problem by choosing a starter culture suitable for this purpose, namely a starter culture whose essential component consists of heterofermentative lactobacilli with acetate-free C ₂ product (patent claim 1).

This lactobacillus is preferably structured so that whose C product consists essentially of L-lactate, especially less than 5% D-lactate contains (Patent award 2).

Particularly preferred are the heterofermentative Lactobacilli DSM 6037 and / or DSM 6129 as constituents the starter culture used (claims 3 and 4).

Such heterofermentative lactobacilli have hitherto been not known.

The Lactobacillus DSM 6037 is on June 22, 1990 and the Lactobacillus DSM 6129 on July 27, 1990 at the DSM German Collection of Microorganisms and Cell Cultures GmbH, Mascheroder Weg 1b, D-3300 Braunschweig, after the Budapest Treaty has been deposited and received the Entry number DSM 6037 or DSM 6129.

Preferably, the starter culture is additionally an acetate Contained growth additive and / or one or more acetate producing additional lactobacilli attached (patent award 5).

The acetate-containing growth substance and / or the acetate producing heterofermentative lactobacilli the necessary amount of acetate for the growth of the other Lactobacillus component available. In which Acetate-containing growth additive and / or the acetate production Lactobacilli may be based on known substances and / or Lactobacilli are resorted to, for example the heterofermentative Lactobacillus fructivorans.

The starter cultures thus prepared can without control Mechanisms for a long time for sourdough production can be used without their acid production remarkably changed. They ensure the same  remaining favorable fermentation quotient and allow easily a multiple-inoculation. There are bad ones minor changes, but without Influence on the intended use. Furthermore Applicant's experiments have shown that the use the lactobacilli according to claim 5 to a sourdough which produces excellent baked goods, especially breads with highest flavors. Therefor is essentially the acetate-free, d. H. in general only made of ethanol C body of the claimed Responsible for lactobacilli. About him and the acetate Addition (growth substance and / or Lactobacillus) can the Fermentation quotient are controlled very accurately.

As acetate-producing Lactobacillus are suitable prefers the known Lactobacillen (see manual Sourdough, Behr's ... Verlag, 1987, p 152) Lactobacillus brevis ssp lindneri, brevis, fermentum, buchneri and / or - fructivorans (claim 6). Continue preferably added to the starter culture a yeast strain (Claim 7); furthermore preferably and in itself a sugar (eg dextrose, lactose) or Amino acids (eg, sodium glutamate) as a carrier (Claim 8).

A preferred method comprises the following method steps on:

• a) 11 to 20 liters of water at a temperature of 28-30 ° C are in a commercial about 75 l Säurewec given bucket;
• b) about 30 g of the starter culture according to the claims 5 to 8 while stirring in the Given water;
• c) 10-19 kg of rye flour are mixed in;
• d) the mash thus obtained becomes 18-24 hours at 24-28 ° C let stand (claim 9).

According to another preferred method form, the from cereal meal and / or flour, water and starter chile acidified existing mash (claim 10). For this purpose, the already mentioned DE-PS 26 11 972 directed.

Based on the published German patent application P 33 23 081.1-41 is preferably the mash crushed Rest bread added and the resulting mixture sääu (claim 11).

Lactobacillus DSM 6037 has a certain similarity with Lactobacillus reuteri (DSM 20016) or with Lactobacillus fermentum (DSM 20052). He gets taxo as follows rewrite nomically / biochemically:

• 1. gram-positive and catalase-negative;
• 2. Ferments glucose with formation of gas;
• 3. in the API 50 CH test (api bio Merieux GmbH, Nürtingen) positive reaction with the following sugars: D-fructose, D-glucose, lactose, maltose, melibiose, D-raffinose, sucrose;
• 4. ammonia from arginine;
• 5. The hydrolyzate of the cell walls contains the amino acids Aspartic acid, lysine, glutamic acid and alanine; in two-dimensional thin-layer chromatography the hydrolysates of whole cells was subjected to epsilon Aminosuccinyl-lysine detected;
• 6. no growth under aerobic conditions agar surface;
• 7. good growth on MRS-Boullion ¹ in anaerobic pot with gas generation kit BR38 (OXOID) - (Oxoid Deutschland GmbH, Wesel); MRS-ready boulder (Merck) according to De Man et al. (1960), manufacturer's information Universal peptone | 10,0 g meat extract 5.0 g yeast extract 5.0 g di-potassium hydrogen phosphate 2.0 g di-Ammonium 2.0 g D- (+) glucose 20.0 g Tween 80 1.0 g Sodium acetate × 3 H₂O 5.0 g Magnesium sulphate × 7 H₂O 0.1 g Manganese sulphate × H₂O 0.05 g additionally: cysteine 0.05 g Water up to 1000 ml pH 6.5 +/- 0.1
• 8. Grows again in anaerobic medium after resting cells on agar in petri dishes for 4 days Were exposed to air;
• 9. Growth not affected by the addition of CO ₂ to the gas space;
• 10. no growth at 15 ° C, growth at 45 ° C;
• 11. low growth at initial pH 4.0 , good growth at initial pH of 4.5 and above;
• 12. slow growth on micro-inoculum broth (DIFCO) ² and poor growth on non-selective APT medium according to Evans and Niven (1951) ³ ; ²Micro-Inocolum Broth (DIFCO) manufacturer's information Proteose Peptone no. 3 | 5.0 g Bacto Yeast Extract- 20.0 g Bacto dextrose 10.0 g Potassium di-hydrogen phosphate 2.0 g Sorbitan Monooleate Complex 0.1 g additionally: cysteine 0.5 g least. Water up to 1000 ml pH 6.7 ³Non-selective APT medium for Lactobacilli according to Evans and Niven (1951) Tryptone (Difco) | 10.0 g Yeast Extract (Difco) 5.0 g di-potassium hydrogen phosphate 5.0 g sodium citrate 5.0 g sodium chloride 5.0 g glucose 10.0 g Tween 80 1.0 g Magnesium sulphate × 7 H₂O 0.8 g Manganese chloride × 4 H₂O 0.14 g Iron sulphate × 7 H₂O 0.04 g additionally: cysteine 0.5 g least. Water up to 1000 ml pH 6.7-7.0;
• 13. Poor Growth on Acetate-Free MRS Boullion According to De Man et al. (1960) ¹ , changing the morphology of short (cocoa) rods to very long and curved rods;
• 14. Reduction of doubling time t _D = 7.5 h at 0.05 g / l sodium acetate tri-hydrate to t _D = 3.0 h at 2 g / l; no further shortening of the doubling time with increase of the acetate concentration;
• 15. Produces in an MRS modified medium ¹ containing 10 g of glucose (instead of 20 g of glucose) and 0.2 g of sodium acetate trihydrate (instead of 5.0 g of sodium acetate trihydrate) per liter under anaerobic conditions (with oxygen-free Nitrogen gassing, addition of 0.05% cysteine before sterilization) L-lactate and ethanol (D-lactate less than 5% of the total amount of lactate);
• 16. Ferricates sugar via the pentose phosphate pathway; To detect phosphoketolase activity;
• 17. may lyophili if added stabilizer  and then at -20 ° C for at least 3 months are stored, the germ count only insignificant decreases.

The growth and product formation of DSM 6037 under anaerobic conditions with pressure equalization in the medium ⁴ reproduced below shows the attached Fig. 1.

⁴Modified MRS medium for analysis of fermentation products Universal peptone | 10,0 g meat extract 5.0 g yeast extract 5.0 g di-potassium hydrogen phosphate 2.0 g di-Ammonium 2.0 g D- (+) glucose 10.0 g Tween 80 1.0 g Sodium acetate × 3 H₂O 0.2 g Magnesium sulphate × 7 H₂O 0.1 g Manganese sulphate × H₂O 0.05 g additionally: cysteine 0.5 g Water up to 1000 ml pH 6.5 +/- 0.1

The apparent in Fig. 1 small amount of acetate is due to the acetate content of the medium ^{4 used} . The decrease in the acetate content is explained by the acetate consumption of DSM 6037. Furthermore, FIG. 1 shows a two-phase growth of DSM 6037, preference being given to product formation in phase I. By the end of Phase II DSM 6037 consumes 17% of the added acetate. In Phase II, much ethanol and L-lactic acid are formed. The ratio of L-lactic acid to D-lactic acid was 1 / 0.02 at the end, and the ratio of L-lactic acid to ethanol was 1 / 1.2.

Lactobacillus DSM 6129 is as follows to describe taxonomically / biochemically: He agrees with the aforementioned taxonomic / biochemical  Parameters 1 to 17 with DSM 6037 match, but fermented additionally galactose in the API 50 CH test.

DSM 6037 and DSM 6129 were isolated as follows: A sourdough sample was diluted 1:10 with saline and centrifuged. The supernatant was diluted and diluted to MRS Agar streaked. The plates were at 37 ° C in Anaerobic pot with Oxoid gas kit BR 38 two to three days incubated. The results obtained by repeated spreading Pure cultures were identified by the API 50 CH assay. Notwithstanding the manufacturer 's instructions, the Microreaction vessels not sealed with paraffin oil, but the test strips were placed in the anaerobic pot with gas Kit incubated.

The lactobacilli according to the invention can be, for example be brought into a storable form as follows:

400 ml of modified MRS medium (see parameter number 15 above) in 500 ml laboratory bottles with screw caps were aerated with oxygen-free nitrogen before 0.05% cysteine was added and the bottles were closed with a screw cap. The medium was inoculated with 8 ml of a 10 hour old preculture in MRS boullion and incubated at 37 ° C. After 16 hours, an optical density OD ₅₇₈ of about 2 and a pH of 4.4 was achieved. The cells were separated from the culture broth by centrifugation, washed with saline and suspended in a 10% skimmed milk solution, frozen and lyophilized.

The lactobacilli according to the invention can be, for example used for sourdough production as follows:

• - 20 liters of water at a temperature of 28 ° C-30 ° C are used in a commercial 75 l Säureweckerkü bel, mostly a plastic bucket.  
• - 30 g of a starter culture are trickled into the water with simultaneous whisking with a whisk. The starter culture is composed as follows: a) Lactobacillus DSM 6037 | 6.0 g b) Lactobacillus fructivorans (acetate producer) 1.2 g c) a yeast strain 2.5 g d) dextrose as a carrier 20.3 g
• - Then 10 kg of rye flour are added and well mixed.
• - The mash thus obtained is at 24 ° C-28 ° C 18-24 Hours left. The quality of the sourdough obtained regularly becomes significant increased, if you do not have the mash in Säurewec Kerkübel, but in a well-known Sauerteiganla ge, with or without kneader, stand, d. H. acidify, if necessary let it acidify.

The above embodiment may be changed as follows become:

• - 15 liters of water
• - 15 kg of rye flour
• - 26 ° C-28 ° C
• - the remaining parameters unchanged or
• - 11.25 l of water
• - 18.75 kg of rye flour
• - 26 ° C-28 ° C
• - the remaining parameters unchanged.

Instead of DSM 6037 can also DSM 6129 or a mixture of these Strains are used. As acetate producers can various heterofermentative lactobacilli strains be used.

Claims (11)

Anspruch [en] A process for making a sourdough of cereal bread and / or flours and water using a heterofermentative lactobacilli-containing starter culture for the preparation of bread and bakery products, characterized in that the starter culture contains heterofermentative lactobacilli with an acetate-free C ₂ product. 2. The method according to claim 1, characterized that the C product of lactobacilli is substantially consists of L-lactate, in particular less than 5% Contains D-lactate. 3. The method according to claim 2, characterized by the Lactobacillus DSM 6037. 4. The method according to claim 2 or 3, characterized through the (additional) Lactobacillus DSM 6129.   5. The method according to any one of the preceding claims, characterized in that the starter culture additionally an acetate-containing growth additive and / or one or more acetate-producing others Lactobacilli is / are attached. 6. The method according to claim 5, characterized that as acetate-producing lactobacilli Lactoba cillus brevis ssp lindneri, - brevis, - fermentum, - buchneri and / or fructivorans. 7. The method according to claim 5 or 6, characterized gekenn records that the starter culture is a yeast strain is added. 8. The method according to any one of claims 5 to 7, characterized characterized in that the starter culture is a sugar (Dextrose, lactose) or amino acids (sodium Amate) are added as a carrier. 9. The method according to claims 5 to 8, gekennzeich net by the following process steps:

• a) 11 to 20 l of water at a temperature of 28-30 ° C are placed in a commercial, about 75 l acidity bucket
• b) About 30 g of the starter culture are added with simultaneous stirring in the water
• c) 10 to 19 kg of rye flour are mixed
• d) the mash thus obtained is allowed to stand at 24-28 ° C for 18 to 24 hours.

10. The method according to any one of the preceding claims, characterized in that the grain from and / or flour, water and starter culture existing Mash is acidified. 11. The method according to claim 10, characterized that the mash crushed leftover bread added  and the resulting mixture is acidified.