DE3742318A1 - Process for the isolation of high-grade feed protein from whey - Google Patents

Abstract

The invention relates to a process for isolating high-grade feed protein from whey and can be used in milk-processing enterprises or in agricultural enterprises, situated in the periphery thereof, with livestock fattening, predominantly of monogastric animals. The object of the invention is a fermentation process for raw whey under varying feed concentrations, with maximum yield of the whey constituents to give high-grade feedstuff. The object is achieved by use of a mixed population of yeasts of the genera Debaryomyces, Kluyveromyces, Pichia, Aciculoconidium and Hansenula in defined ratios to each other with addition of ammonium sulphate as sole nitrogen source. The process is carried out at a pH of 1.8-2.3. The use of this mixed population in defined proportions permits a yield increase of biomass generated of more than 20%. After a following thermolysis, the protein - and vitamin-rich product has a high dietetic effect and produces a higher feed utilisation.

Description

The invention relates to a biotechnological method for the cultivation of yeast by aerobic continuous Fermentation of whey ingredients under targeted technological conditions and the extraction of high quality Food protein.

The invention can be found in the milk processing industry can be used to improve the whey ingredients a high quality protein feed to generate for the mast of monogastrids. The invention is in the IPK A 23 K 1/08 and C 12 N 1/16 to classify.

The fermentation of whey, with the aim of being usable Ingredients, especially lactose and lactic acid, convert to raw protein and thereby the value Increasing the whey waste product becomes extensive described in the technical and patent literature. By doing Review article MICROBIAL BIOMASS by I. Meyroth and K. Bayer (published in 1979 by the ACADEMIC PRESS publishing house, London, New York, Toronto, Sydney, San Francisco, S. 208-269) is an extensive compilation about the research carried out in the field fermentation of whey and the results achieved submitted. The conclusion of this compilation is that the Liquid liquid carbohydrate waste a logical refinement step is that only in industrial fermentation of whey in some cases was carried out because the protein feed obtained from whey with the other protein feeds priced  must compete. Those described in the patent literature Inventions are through subsequent process stages marked:

• -Molk storage and cooling at temperatures around 10 ° C
• - Protein separation from the whey
• - fermentation
• - Processing of the fermenter drain gradually a dry product
• - Packaging of the product.

These individual process steps require extensive apparatus, measurement technology and control technology Expenditure.

In several patent applications (DE-OS 24 03 306.5, DE-OS 24 10 349.9, DE-OS 25 00 323.0, DE-OS 26 56 663.2, DE-OS 27 52 485.2) a process was claimed in which whey and lactose-containing milk products Wastewater is fermented, but all in total have the disadvantage that either only one defined Yeast strain is used, or combinations of Yeast strains and bacteria are used initially convert the lactose to lactic acid and then selectively Assimilate lactic acid and produce protein. In French Patent No. 80 22 401 described the use of a mixed population that the The aim is in a community of different strains of yeast the different components of the medium to utilize and thereby increase the yield. The culture medium becomes whey through the yeast strains

Kluyveromyces fragilis
Kluyveromyces lactis
Turolopsis horina

fermented. The conditions for the fermentation process  are at 30-40 ° C, a pH of 3-4 and the Addition of certain trace salts. Every yeast strain is there responsible for the turnover of a certain ingredient. In the order of lactose, lactic acid, alcohol are the listed yeast strains for the fermentative Dismantling responsible. It is a disadvantage, that the aerobic fermentation process causes the emergence of Allows alcohol. This disadvantage can also be seen in the derive French Patent No. 78 30 229 where the production of biomass and alcohol and its subsequent Utilization to protein is described. Furthermore is for the perfect functioning of the process in the inventions mentioned the separation of the in the Protein contained in whey is required. This will either by heat precipitation or an additional separation stage, in which an ultrafiltration with suitable membranes applied for the selective separation of the whey proteins is realized.

The aim of the invention is to increase the yield of biomass produced when fermenting whey ingredients to reach. The quality of the generated biomass, measured by digestibility and the master results, the comparable products be the same or superior. Due to a high protein and vitamin content of the product is said to increase the Feed utilization can be achieved.

The invention has for its object a continuous To develop a process that is trouble-free Production process of the production of feed protein from whey with fluctuating feed concentrations on lactose, lactic acid and whey proteins as well as metabolic products of the cultures contained in the whey from cheese production with a maximum yield of Whey ingredients to ensure high-quality feed.  According to the invention, the object is achieved by that a defined mixed population of yeasts Genera Debaryomyces, Kluyveromyces, Pichia, Aciculoconidium and Hansenula in a high-performance fermentor with special fermentation conditions on the Substrate whey is fermented. Surprisingly it was found that a mixed population of the yeast strains

Debaryomyces hansenii LH 306 (ZIMET 43 788)
Kluyveromyces marxianus LH 35 (ZIMET 43 786)
Pichia norvegensis H 73 (ZIMET 43 787)
Aciculoconidium aculeatum H 308 (ZIMET 43 790) and
Hensenula jadinii H 307 (ZIMET 43 789),

which in the order mentioned to a proportion between

75 and 82%, preferably 78% 12 and 18%, preferably 15% 3 and 5%, preferably 4% 1 and 3%, preferably 2% as well 0.5 and 2%, preferably 1%

present in the mixture, the carbonaceous ingredients to a high-quality protein feed used with a high vitamin content.

The composition of the mixed population according to the invention is placed in the fermentor and according to the Start-up regime for untreated whey, rennet or sour whey, added. This mixture is added with the for the fermentation necessary nitrogen requirement in the fermentor fermented aerobically. With a dwell time of 4 Hours will be necessary depending on the size of the fermenter Whey quantity supplied. The fermenter temperature is adjusted to 30 to 40 ° C, preferably 35 to 37 ° C. The dissolved oxygen level is approx. 20%. According to the nitrogen consumption of the yeast  only an ammonium sulfate solution is added as a nitrogen source, the nitrogen supply corresponding to a residual nitrogen concentration of 250 mg / l is set. The Process is at a pH of 1.8-2.3 and a density operated from 400 to 550 kg / m³. These technological parameters ensure a stable process flow. In trial operation the fermentor was operated continuously for 17 months. The monthly taxonomic controls showed only slight fluctuations from the specified mean of the Concentration of the individual strains. It was an increase in yield with biomass produced compared to other processes record more than 20%.

The fermenter drain is immediate or after concentration through thermal or membrane separation stages in a modified Plate heat exchangers at temperature from 80 to 95 ° C, preferably at 84 to 87 ° C, and a residence time from 40 to 80 s, preferably 45 to 60 s, salmonella-free thermolyzed. With a preferred use in the mast of monogastrides arises from the high protein and Vitamin content and the dietary effect of the product Increase in feed utilization by at least 20%.

With the method according to the invention, a product was obtained which can be characterized as follows:

Dry matter content 43-45 g / l crude protein content 20-22 g / l residual lactose content max. 1 g / l content lysine 35 g / kg DM content methionine / cystine 15 g / kg DM content vitamin
- B₂60 mg / kg TS - B₁₂5 mg / kg TS - E15 mg / kg TS phosphorus content15 g / kg TS

Embodiment

The whey that accumulates daily in a cheese dairy arrives in a freshly cleaned tank and is cleaned by here from a dosing pump the CLG jet fermenter fed.

When starting the process, the presented invention Mixed population of untreated raw whey added and the fermentor in the batch process operated until the lactose content is used to <1 g / kg is. The approach is still ammonium sulfate solution for the adequate yeast growth added to the ingredients. When the lactose is almost completely broken down, started dosing whey. The dosage is gradually increased from 200 kg to 1 t / h. Conditionally through the operating principle of the CLG beam fermenter and the emulsifying property of the whey arises a density in the fermentor of 400-550 kg / m³. The resulting dwell time fluctuation has been practical no influence on the yeast yield in the fermentor. in the Trial period of the continuous over several months Experimental operation was a biomass production from 28.2 ± 2.4 g / kg whey determined.

The ammonium sulfate solution is added accordingly the yeast growth and the throughput of the plant via a Dosing pump, controlled by the content of assimilable Residual nitrogen in the substrate.

Depending on seasonal fluctuations in the whey composition even minor amounts are different Trace salts added. The process is at one pH of 1.8-2.3 operated. So it won't be like in the literature and the inventions mentioned the pH to an alleged optimum of 3.8-4.2 regulated, but through the interaction of the different  Yeast types are also optimal at this pH Yield achieved. Also, by the pH from 1.8-2.3 other organisms, especially bacteria, like Salmonella, kept out of the process.

The microbiological control results in a clean one Cell image in which the mixed population used according to the invention is present in the selected composition clean. The fermentation temperature is at 35-39 ° C adjusted. The composition of the invention Yeast population was over the experimental period of 8 Months checked several times, and it became practical no significant deviations from the stated average detected.

What was said to run continuously from the fermentor Substrate is stacked in a container and degassed. The degassed cured whey is sent to the thermolysis facility fed. A milk heater is used for the thermolysis used for this purpose after a special regime is operated. The protein concentrate obtained in this way will be fed to fattening pigs fed. The one obtained according to the present description Feed concentrate was obtained from the pig fattening in an experiment on 90 pigs over an entire fattening section fed in practical conditions. Next a very good feed intake and a very good one Compatibility became above average foraging results reached. It can also be shortened the effectiveness of the fattening system considerably be increased.

Claims (4)

1. A process for obtaining high-quality feed protein from whey by combining the whey constituents with a defined yeast mixed population in a ventilated high-performance fermentor, preferably a CLG jet fermenter, characterized in that the whey with a mixed population from the yeast strains Debaryomyces hansenii LH 306 (ZIMET 43 788)
Kluyveromyces marxianus LH 35 (ZIMET 43 786)
Pichia norvegensis H 73 (ZIMET 43 787)
Aciculoconidium aculeatum H 308 (ZIMET 43 790) and
Hansenula jadinii H 307 (ZIMET 43 789), the yeast strains in the mixed population in the order listed in a proportion between 75 and 82%, preferably 78% 12 and 18%, preferably 15% 3 and 5%, preferably 4% 1 and 3 %, preferably 2% and 0.5 and 2%, preferably 1%, at a temperature of 30 to 40 ° C, preferably 35 to 36 ° C, a pH of 1.8 to 2.3 and a density from 400 to 550 kg / m³ is continuously aerobically fermented with the addition of the necessary nitrogen requirement. 2. The method according to item 1, characterized in that as Untreated rennet and / or sour whey substrate used becomes. 3. The method according to item 1, characterized in that for Only the ammonium sulfate solution meets the nitrogen requirements of the yeast is fed.   4. The method according to items 1-3, characterized in that the Fermentor drain immediately or after concentration by thermal or membrane separation processes below in a modified plate heat exchanger at a Temperature of 80 to 95 ° C, preferably 84 to 87 ° C, and a residence time of 40 to 80 s, preferably 45 to 60 s, is thermolyzed.