DE1618354A1 - Process for the production of crystallized fructose - Google Patents

Description

FARBENFABRIKEN BAYER AG

LEVERKUSEN-Bayenwik Jan. 25, 196? Patent department Si / Rb

Process for the production of crystallized fructose

For the production of fructose are suitable as starting materials Polyfructosides such as inulin or levan, which must be hydrolyzed, or mannitol, which is microbiological Oxidation at carbon atom 2 converts into the desired monosaccharide.

Another particularly inexpensive raw material for production that can be obtained in any quantity at any time of fructose is sucrose. It can easily be converted into equal parts fructose and glucose by inversion

That is why there has been no shortage of attempts to obtain fructose from sucrose. In this case, however, the problem arises of quantitatively separating the two water-soluble monosaccharides formed during inversion from one another in a simple and technically easily feasible manner. -

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The sucrose can also, instead of inversion, use enzymatic polymerisation of one of its two components be split.

It has already been proposed to allow the enzyme dextran sucrase, the dextran formed, to act on sucrose to be separated by precipitation with solvents and to obtain fructose from the remaining solution ^ "part of the patent 2 729 587_7

Furthermore, attempts have recently become known, initially by the action of levan sucrase on sucrose to produce, isolate it by precipitation with solvents and then hydrolyze it with acids / ~ DDR Patent-247637 ·

One way of separating fructose from aqueous solutions has been known for almost 90 years ^ "Tollens-Elsner "Brief Handbook of Carbohydrates". 4 · Edition, page 381, 1935_7 · It consists in calcium hydroxide on Allowing the cooled fructose solution to take effect, the calcium fructosate which is separated out in the process to be obtained and in aqueous Suspension with carbon dioxide, oxalic acid or sulfuric acid disassemble. This process is generally applicable, e.g. also for the isolation of fructose from invert sugar or from

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Solutions in which see by Lobry de Bruyn / Van Ekenstein's Rearrangement from glucose to fructose has arisen ^ "Deutsche Auslegeschrift 1 '63 3077.

Calcium fructosate is, however, especially with an excess of calcium hydroxide, easily decomposable. It is therefore required to continue to increase this intermediate product very quickly. to process.

To avoid the disadvantages of the calcium fructosate process, The proposal was recently made to microbiologically oxidize the glucose in invert sugar with Aspergillus niger and to convert it into gluconic acid. This is then after neutralization as a water-soluble sodium or calcium salt separated by precipitation with methanol /~U.S. Patent 3 050 4447-

In all of these processes, the aggravating fact that even small amounts of impurities cause the tendency to crystallize plays a role inhibit fructose. It is therefore necessary to use all conceivable by-products that z. B. from ions or Monosaccharides may exist, carefully remove. at It has therefore proven necessary to use ion exchangers to remove the thin juices from all the processes that have become known so far further to clean / "Ulimann: Enzyclopaedie der technischen Chemie, Vol. 9, page 662 (1957) 7 ·

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It has now been found that crystalline fructose can be produced in good yield if invert sugar solutions are used in the presence of calcium carbonate oxidized with Acetobacter suboxydans', resulting 5-ketogluconic acid calcium removed and fructose wins from the residual solution in a known manner.

Although it is known that Acetobacter suboxydans glucose over Gluconic acid oxidized to 5-ketogluconic acid, but it was surprising determine that even in the presence of high fructose concentrations, the glucose quantitatively converts to 5-ketogluconic acid can be implemented.

In the method according to the invention, a complex organic nutrient solution, such as corn steep liquor solution or yeast extract solution, is mixed with invert sugar solution and a suspension of calcium carbonate and this mixture is inoculated with a culture of .icetobacter suboxydans. The batch is kept at 25 to 30 ^{° C. with vigorous aeration.} During the fermentation, further invert sugar in the form of a concentrated solution and corresponding amounts of calcium carbonate can be added in order to neutralize the 5-ketogluconic acid formed during the oxidation of the glucose by converting it into the very poorly soluble calcium salt.

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BATH ORIGINAL

In order to obtain a good yield of pure fructose, it is necessary to quantitatively convert the glucose to 5-ketogluconate to oxidize. The time required for this depends on the reaction conditions, e.g. B. from the concentration of invert sugar, ventilation intensity, temperature, etc. and can range from 12 hours to 200 hours.

After the reaction has ended, the crystalline calcium 5-ketogluconate precipitate can easily separated from the relatively low-ion supernatant solution. This contains practically quantitatively the unchanged fructose, which can be extracted from it particularly easily by methods known per se, e.g. treatment with ion exchangers, concentration in a vacuum, precipitation with lower alcohols etc. in crystalline form can be won.

The process according to the invention provides crystalline fructose in a simpler way than the known methods.

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example

A. Preculture

A nutrient solution of the composition

2.80 kg of mannitol

0.20 kg of yeast extract

0.04 kg K ₂ HPO ₄

5.0 ecm silicone oil

38.0 ltr. tap water

is adjusted with H ₂ SO ₄ to pH 5.8, sterilized 45 minutes at 110 ⁰ C and after cooling at 4OO ecm a Sehüttelkultur of Acetobacter suboxydans inoculated. For cultivation, the inoculated nutrient solution is ^{aerated for 24 hours at 28 °} C. while stirring with 50 liters of air per minute.

B. Main culture

In a 1500-liter fermentor, a mixture of 16 kg CaCO ^, 200 cc of silicone oil and 480 liters of tap water is sterilized for 45 minutes at 110 ⁰ C. In a 120-liter kesael, 80 liters of 5.0 # cornqjiell water solution with KOH are added

Sterilized for 45 minutes at 11O ⁰ C. In a further separate boiler 200 liters 60 $ owned Imrertzuekerlösung sterilized for 30 minutes at 11O ⁰ C. After cooling these separately prepared solutions, the corn steep water solution and the invert sugar solution are combined with the CaCO ^ suspension in the fermenter. The so

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The nutrient solution produced is inoculated with the preculture described under A) and kept at 28 ^° C. At 150 revolutions of the agitator per minute, the Permentati onsansatz is aerated without excess pressure with 400 liters of air / min.

After about 19 hours of fermentation, the pH has dropped to 4.7 to 4.2. One lets it out of storage kettles Now culture 100 liters of sterile 60 $ invert sugar solution and 32 liters of sterile 25% CaCO ^ suspension run in. The air supply is increased from 400 to 800 liters of air / minute.

After approx. 25 hours of fermentation the pH value is again dropped to 4.7 to 4.2. 133 liters of sterile 60% invert sugar solution and Liters of sterile 25% CaCO ^ suspension added.

After a fermentation time of about 33 hours followed

at a pH of 5.0 1 to 4.7 additions of 100 liters

sterile ^ O ^ igj & r.Jnxei & tzu ^ cker solution and 40 liters sterile CaCO ^ suspension.

After a fermentation time totaling the glucose present in the invert sugar via gluconic acid quantitatively to 5-ketogluconic acid, which is practically un-

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soluble gas salt is present in the culture broth, oxidizes been. The volume of the culture broth is now 950 liters. About 200 liters of the theoretical final volume are considered Water vapor evaporates. After separation of the Ca-5-ketogluconate crystal precipitate centrifugation gives about 800 liters of solution in which 17% = 85% of theory are in fructose.

G. Work-up

6.0 liters of the calcium-5-ketogluconate-freed solution are adjusted to pH 9.5 with 5 η sodium hydroxide solution, with 6.0 g of medicinal charcoal DAB 6 and 6.0 g of Clarcell for 15 minutes stirred and then filtered through a Seitz-K 3 layer. 220 ml of Amberlite IRA 400 in the OH form are then introduced into the solution and stirred for 3 minutes. To Filtration is treated in the same way with 6600 ml of Amberlite IR 120 in the Η form. The solution has afterwards a pH below 4. By adding Amberlite IRA 400 in the OH form, it is neutralized. The clear one The completely colorless solution then contains 873 g of fructose. It is evaporated in vacuo to a content of 90 to 95% fructose and 5 to 10% water, with the same Volume of methanol is added and after the addition of 25 g fine

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free powdered crystallized fructose 5 C under slow rotation canceled ¹ 16 hours. The fructose crystallizes out.

Yield 686 g ^r

O,

Melting point: 103 ^° C

Mixed melting point with pure fructose: T03

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The mother liquor contains another 212 g of pure fructose, which can be processed together with the next approach.

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Claims (1)

Claim Process for the production of crystallized fructose, characterized in that invert sugar solutions in the presence of calcium carbonate with Acetobacter suboxydans oxidized, 5-ketogluconic acid calcium formed removed and fructose is obtained from the residual solution in a manner known per se. Le A 10 518-10-109813/1843