PROCESS FOR OBTAINING GLYCAN EXTRACTS FROM APPLE POMACE, PROCESS FOR PRODUCING FUNCTIONALIZED GLYCANS, AND FUNCTIONALIZED GLYCAN THAT CAN BE PRODUCED BY THE PROCESS AND ITS USE

Abstract

Disclosed is a process for obtaining glycan extracts from apple pomace in which a mixture comprising apple pomace and water is extracted into water so that an aqueous glycan extract is obtained; at least one alcohol is added to the extract, whereby a solid glycan extract is precipitated; and the solid glycan extract is separated from the liquid. Also disclosed is a process for producing functionalized glycan wherein the glycan is converted using at least one amine into at least one functionalized glycan. Also disclosed are a functionalized glycan that is produced by the method and uses thereof

Claims

1-16. (canceled)

17. A process for obtaining a glycan extract from apple pomace, the process comprising: (a) providing a mixture comprising apple pomace and water; (b) subjecting the mixture to an extraction treatment in which at least one glycan is extracted from the apple pomace into the water so that an aqueous glycan extract is obtained that comprises the at least one glycan; (c) adding at least one alcohol to the aqueous glycan extract, whereby a solid glycan extract is precipitated that comprises the at least one glycan; and (d) separating the solid glycan extract from the liquid.

18. The process according to claim 17, wherein the mixture produced in step a) has a mass ratio of apple pomace to water of 1:2 to 1:50.

19. The process according to claim 17, wherein the apple pomace comprised in the mixture provided in step a) is depectinized.

20. The process according to claim 17, wherein the extraction treatment in step b) takes place at a temperature in a range from 80° C. to 300° C.; and/or over a time period of 20 minutes to 8 hours.

21. The process according to claim 17, wherein the aqueous glycan extract is separated from the solid between steps b) and c) by a method selected from the group consisting of filtration, centrifugation, and combinations thereof.

22. The process according to claim 17, wherein the at least one alcohol is selected from the group consisting of ethanol, methanol, isopropanol, and mixtures thereof; and/or is added to the aqueous glycan extract for so long until it is present in the mixture produced in a concentration that is in the range from 50% vv to 99% vv.

23. The process according to claim 17, wherein the separation of the solid glycan extract from the liquid in step d) takes place by a method selected from the group consisting of centrifugation, filtration, and combinations thereof.

24. The process according to claim 17, wherein the solid glycan extract is dried after step d).

25. A process for producing functionalized glycan comprising (i) obtaining a solid glycan extract from apple pomace that contains at least one glycan according to claim 17 and converting the at least one glycan into at least one functionalized glycan by reacting with at least one amine.

26. The process according to claim 25, wherein the at least one functionalized glycan is separated from reactants and/or secondary products.

27. The process according to claim 25, wherein the at least one amine is selected from the group consisting of 2-chloro-N,N-diethylethylamine, 2-chloro-N,N-dimethylethylamine, 3-dimethylamino-1-propyl chloride, 1-(2-chloroethyl)-pyrrolidine, 1-(2-chloroethyl)piperidine, 1-(3-chloropropyl)piperidine, (2-chloroethyl)trimethylammonium chloride, and (3-chloro-2-hydroxypropyl)trimethylammonium chloride.

28. The process according to claim 25, wherein the conversion is carried out by dissolving the solid glycan extract in at least one solvent, the resulting solution is admixed with the at least one amine, and the resulting reaction mixture is subjected to a temperature treatment.

29. The process according to claim 28, wherein the temperature treatment is subjected at a temperature in a range from 10° C. to 150° C.; and/or over a time period of 30 minutes to 24 hours; and/or with stirring.

30. The process according to claim 28, wherein sodium hydroxide is added to the solution before the solution is admixed with the at least one amine in the conversion step.

31. A functionalized glycan produced by the process of claims 25.

32. A method of making a binder for a paint, an additive for a printing ink, an additive for paper making, and/or adhesive in a biocompatible material comprising utilizing a functionalized glycan according to claim 31.

Description

EMBODIMENT

[0068] An exemplary performance of the process in accordance with the invention for obtaining glycan extracts and of the process in accordance with the invention for producing functionalized glycans are described in the embodiment. A glycan or a mixture of glycans from apple pomace is first obtained here. Subsequently a single stage aminization of the obtained glycan or of the acquired glycans can be achieved by attaching DEAE in homogeneous systems. The degree of substitution is determined by the determination of the N content by means of elementary analysis.

[0069] The obtaining of the glycan or glycans from apple pomace is shown schematically at pilot plant scale in FIG. 1. A mixture comprising apple pomace 1 and water is first provided in an extractor 2. The apple pomace was here already depectinized by the manufacturer by a pre-treatment with sulfuric acid. The apple pomace is used without any further purification. On a dry substance base, the material of batch A comprises approximately 4.3% hemicelluloses and batch B approximately 5.8% (in accordance with expanded Weender analysis).

[0070] In the extractor 2, the mixture is subjected to an extraction treatment in which a glycan or a plurality of glycans is/are extracted from the apple pomace 1 into the water so that an aqueous glycan extract is obtained that comprises the glycan or glycans. With an extraction volume of 60 liters, the extraction is carried out here at a mass ratio of solid (i.e. apple pomace) to water of 1:25. The extractor 2 is vented or purged with nitrogen and the suspension is extracted in a percolation process (50 L/min) at 145° C. for 90 minutes. Subsequently, the suspension is speedily cooled down with water to 50° C. and the aqueous glycan extract is separated from the solid 3, i.e. the solid residues of the apple pomace, via a filter station using filters of a mesh of 40 μm and is conducted via a pipe 4 into a precipitation reactor 5. A solid glycan extract that comprises the glycan or glycans is precipitated in the precipitation reactor 5. The precipitation takes place while adding ethanol that is conducted from an alcohol reservoir 6 into the precipitation reactor 5 until an 80% solution is reached. The subsequent isolation 7 of the solid glycan extract takes place via a filter station having nylon filament (nominal pore width 1 μm). The solid glycan extract is then subjected to drying 8.

[0071] The liquid remaining in the precipitation reactor 5 on the isolation 7 is conducted into a storage reactor 9 and a rectification column 10 where a rectification takes place. The ethanol obtained by the rectification is again conducted into the alcohol reservoir 6. The remainder 11 remaining after the rectification is drained off.

[0072] Alternatively to the just described pilot plant scale, glycan can also be obtained from apple pomace at lab scale. At a lab scale (extraction volume 50 mL), the extraction is treated with a mass ratio of solid to water of 1:10 at 200° C. for 130 minutes in a pressure digestion device without stirrer. The obtained extract is filtered and the apple glycan or glycan mixture is precipitated by adding alcohol at a concentration of 80% (v/v). The apple glycan or glycan mixture is filtered. 5% of the initial weight is obtained after the drying.

[0073] The apple glycan or glycan mixture obtained at pilot plant scale and at lab scale was examined with respect to its protein content and polyphenol content and the weight mean molecular mass and the sugar fraction were determined. Independently of the extraction process, the protein content is 1.2% (CHNS pilot plant scale—C: 30.5 h/ 34.9, H: 5.0/ 5.9, N: 0.2/ 0.1, S: 3.8/2.3: CHNS lab scale—C: 35.6 H 6.2, N: 6.2, N: 0.2 S: 1.0) and the polyphenol content below 1%. The weight mean molecular mass fluctuates between 27 and 36 kDa (calibrated to Pullulan) depending on the batch of apple pomace used. This is illustrated by FIGS. 2a and 2b in which GPC chromatographs of the apple pomace batches A (FIG. 2a) and B (FIG. 2b) are shown at pilot plant scale. This fluctuation starting from the apple pomace batch used can likewise be observed in the sugar distribution, particularly in the ratio of glucose to galactose. This is illustrated by Table 1 and by FIGS. 3a, 3b, 3c, and 3d, where FIGS. 3a to 3d show HPIC chromatographs of the apple pomace batches A and B at lab scale and at pilot plant scale. A reduction of the total sugar from the lab scale to the pilot plant scale is furthermore shown (65.9% to 57.5%).

TABLE-US-00001 TABLE 1 Sugar distribution of the apple pomace batches A and B at lab scale and at pilot plant scale Glucose Galactose Xylose Mannose Arabinose Total [%] [%] [%] [%] [%] [%] AT Batch 43.5 19.3 5.9 2.2 1.0 71.8 A-lab- AT Batch 40.9 19.9 6.4 3.5 1.3 72.0 A-pilot plant/lab- AT Batch 32.0 25.0 6.1 2.0 0.8 65.9 B-pilot plant/lab- AT Batch 25.5 21.0 7.1 3.1 0.9 57.5 B-pilot plant-

[0074] In a further step, the aminization of the glycan or glycans in the glycan mixture can take place at the lab scale of 200 mg up to 15 g of the starting material. The apple glycan or glycan mixture is dissolved in water (30-36 w/v%) and sodium hydroxide (6 equivalents) is added while stirring. Subsequently, 2-chloro-N,N-diethylethylamine hydrochloride (3 equivalents) is added to the reaction mixture and is stirred at 58 to 60° C. for 5 hours. The reaction is ended by neutralizing the mixture and is dialyzed at 6° C. with water for 5 to 7 days. 45 to 98% of a beige solid is obtained after drying. The yield decreases here as the preparation size reduces.

[0075] The obtained DEAE apple glycan or DEAE glycan mixture was examined by means of elementary analytics and the degree of substitution (DS) was determined using the determined nitrogen content (see Table 2). The nitrogen content is 3.3 to 3.8% and the DS determined therefore is 0.50 to 0.58.

TABLE-US-00002 TABLE 2 CHNS analytics of the different lab preparations Preparation size CHNS [%] DS (DEAE) 0.2 kg C: 46.2 H: 8.0, N: 3.8, S: 0.2 0.58 2.0 kg C: 45.2 H: 8.1, N: 3.5, S: 0.6 0.52 15.0 kg  C: 44.9 H: 7.6, N: 3.3, S: 0.9 0.50

[0076] This corresponds to one DEAE substituents per two, possibly three, glucose units since the synthesis introduces two kinds of DEAE substituents into the glycan molecule. This is illustrated by FIG. 4 in which the chemical synthesis of the aminization of apple glycan with 2-chloro-N,N-diethylethylamine is shown schematically. The predominant substituent is the single tertiary group that, however, in particular reacts further at a higher DS and produces a “tandem” group that comprises both a quaternary amine and the tertiary amine.

[0077] In comparison with the commercial DEAE dextran (mean value=10,000 g/mol), DEAE apple glycan displays similar properties with respect to the nitrogen contact. The nitrogen content of DEAE dextran amounts to 2.5 to 4.5% and the degree of substitution (DS) to be determined therefrom is 0.33 to 0.75: the content of DEAE glycan is exactly in the middle thereof at 3.3 to 3.8% and a DS of 0.50 to 0.58. The water solubility of DEAE glycan at 140 mg/ml shows an improvement over that of DEAE dextran at 100 mg/ml. This would be due to the fact, for example, of the greater branching of the apple glycan over that of the dextran. In addition to the water solubility, DEAE apple glycan (40 w/v %) could likewise be dissolved in a water/ethanol mixture (60/40).