Aqueous dispersion of fructan-containing particles, method of preparation and use

Abstract

An aqueous dispersion of fructan-containing particles, wherein the D.sub.50 of the fructan-containing particles lies between 2 ?m and 50 ?m and the solids content of the aqueous dispersion lies between 61 wt. % and 80 wt. %. Also described is a process for the preparation of an aqueous dispersion of fructan-containing particles comprising: bringing fructan and water together to form a mixture; optionally hydrolyzing a portion of the fructans in the mixture, such that at the end of this step between 5 wt. % and 25 wt. % of all fructans in the mixture are essentially non-soluble at room temperature; optionally bring the mixture into contact with a purification agent, followed by removal of the purification agent from the mixture; and concentrating the mixture such that the solids content lies between 61 and 80%.

Claims

1. A stable non-gel aqueous dispersion of inulin consisting of inulin in solution and particle form dispersed in water, wherein between 5 wt. % and 25 wt. % of the total inulin in the dispersion has a degree of polymerisation (DP) of at least 11, wherein the inulin consists of inulin from chicory roots wherein the particles of inulin in the dispersion have a size distribution, D? of ?, in which the ? wt. % of the particles have a size of at most ?, expressed as D.sub.50 of the particles, of between 2 ?m and 25 ?m, and expressed as D.sub.10 of the particles, of between 0.5 ?m and 5 ?m, wherein the dispersion has a solids content which lies between 61 wt. % and 80 wt. %, and wherein the dispersion has a viscosity of between 5 and 30000 Pa.Math.s, said dispersion being pumpable and stable to separation, coagulation or settlement for at least after 24 hours after preparation, when held at a temperature of between 15? C. and 30? C.

2. The stable non-gel aqueous dispersion of inulin according to claim 1, wherein the inulin in the dispersion has a number-average degree of polymerization (DP) which lies between 5 and 15.

3. The stable non-gel aqueous dispersion of inulin according to claim 1, wherein the dispersion has a viscosity lying between 10 and 4000 Pa.Math.s.

4. A dairy, drink or fruit preparation, comprising the stable non-gel aqueous dispersion of inulin of claim 1.

5. The stable non-gel aqueous dispersion of inulin according to claim 1, wherein the dispersion has a viscosity lying between 500 and 50000 Pa.Math.s.

6. The stable non-gel aqueous dispersion of inulin according to claim 2, wherein the dispersion has a viscosity lying between 1000 and 50000 Pa.Math.s.

Description

(1) The invention will be illustrated by means of the following Figures and Example, without being limited thereto.

(2) In the Figures, FIG. 1 is a photograph of the aqueous dispersion according to Example 1 the invention; this photograph of a sample taken from the top of a container that had stood undisturbed for four months;

(3) FIG. 2 is a photograph of the same aqueous dispersion as in FIG. 1; this photograph, however, is of a sample taken from the bottom of the container;

(4) FIG. 3 presents a Dionex HPAEC (high pressure anion exchange chromatography) chromatogram of the inulin contained in the aqueous dispersion of the invention of Example 1;

(5) FIG. 4 shows a Dionex chromatogram of a native inulin extracted from chicory.

EXAMPLE 1

(6) Measurement of Solid Contents

(7) The determination of solids content was done via measuring the weight difference of a sample before and after vacuum drying. The as such known procedure comprised the following steps: Provision of a small amount of sea sand; Putting the sea sand in a vacuum dryer at 70? C. and at a vacuum of 3500 Pa during 4 hours; weighing of the sea sand, the result being P1 Adding the sample of which the solids content is to be determined to the sea sand; Weighing the thus prepared sample, the result being P2, and putting it in the vacuum dryer at 70? C. and at a vacuum of 3500 Pa during 20 hours; Weighing the sample after drying, the result being P3; Calculating the solids content according to the formula: 100?(P3?P1)/(P2?P1)
Viscosity Measurements

(8) The viscosity was measured in a Rheometer Bohlin CV O50 apparatus. The shear stress was controlled at 1.5 Pa unless noted otherwise. The measurement was conducted at a temperature of 25? C., with no pre-shear being applied and after one hour and a half stabilisation time before measurement.

(9) Measurements of Particle Size

(10) The determination of particle size was done by means of a Mastersizer 2000 apparatus (supplier: Malvern), with Scirocco dry powder feeding unit or a Hydro 2000S unit for liquid samples. The sample was first diluted to a solids content of 60 wt. % and then centrifuged for 90 min at 13000 rpm to separate the suspended particles. After removal of the supernatans, the particles are re-suspended in water to a refractive index of 1.39 and used directly for particle size measurement. The Mastersizer is capable of determining sizes in the 0.02 ?m to 2000 ?m. As is common in this apparatus, a measurement result is an average of 5,000 measurements done over a period of 5 seconds.

(11) Preparation of Mixture and Aqueous Dispersion

(12) A mixture was formed by bringing 840 kg of inulinproduct Orafti GR, supplier Beneo-Oraftiin water such that the inulin was present in 20 wt. %. Inulin GR was characterised by having a number-averaged DP of 12; 70 weight % of the inulin GR had a DP of 11 or more.

(13) The temperature of the mixture was brought to 60? C. The mixture was subjected to a UHT step at 140? C. for 30 seconds.

(14) For the purpose of executing a hydrolysis step, the mixture was then fed into a reactor; the temperature was brought to 60? C., and the pH was lowered to 5.4 by means of H.sub.2SO.sub.4. Subsequently, 280 ml of an endo-inulinase enzyme (Novozymes? 960, batch KNN105) was added. At these conditions, the mixture was allowed to react for 20 hours. The reaction was brought to an end by first raising the pH to 8 with NaOH, then the temperature to 90? C. for 15 minutes; these conditions led to de-activation of the enzymes.

(15) The mixture was cooled to 20? C., in order to execute the purification step: this was done by guiding the mixture through a column with a fixed-bed anion exchange resin type XA100RSCL. Subsequently the pH of the mixture was brought to 6 and the mixture was led over activated carbon (Norit? ROX 0.8) and filtered (0.2-0.4 ?m hole size).

(16) The concentration step was executed on the mixture by using a falling film evaporator, in 4 steps, until a solids content of 72% was achieved. In doing so, the aqueous dispersion was formed and immediately cooled to 22? C. with a tube and shell heat exchanger.

(17) Analysis of Aqueous Dispersion

(18) An analysis on the aqueous dispersion as prepared showed that it had the following properties: Solids content: 72% Viscosity: 60 Pa.Math.s D.sub.10: 2.3 ?m D.sub.50: 8.0 ?m 16 wt. % of carbohydrates, i.e. 11.5 wt. % of the dispersion as a whole, had a DP 11 or more, as measured via Gas Chromatography DP: 6. See also FIG. 3, whereby it is noted that the peak at retention time of 20.0 minutes corresponds to a DP of 10. Stability: very stable; no sedimentation or agglomeration after 4 months of standing, see also FIGS. 1 and 2 where both the absence of agglomeration can be seen as well as the non-occurrence of sedimentation. No gel formation was observed, the aqueous dispersion wasand remainedpumpable

EXAMPLE 2

(19) An aqueous dispersion according to the invention was prepared in the same fashion as in Example 1, with however the following differences: The amount of enzyme added was reduced from 280 ml to 150 ml; Subsequent to the concentration step, the aqueous dispersion was transferred to a vessel equipped with a stirrer and there stirred for 24 hours (shearing step e)).

(20) The aqueous dispersion had the following characteristics: Solids content: 70% D.sub.10: 1.5 ?m D.sub.50: 6.0 ?m 25 wt. % of the carbohydrates in the aqueous dispersion had a DP of 11 or more as measured via Gas Chromatography Stability: very stable No gel formation was observed, the aqueous dispersion wasand remainedpumpable

EXAMPLE 3

(21) An aqueous dispersion according to the invention was prepared in the same fashion as in Example 1, with however the following differences: The amount of enzyme added was reduced from 280 ml to 130 ml; Subsequent to the concentration step, the aqueous dispersion was transferred to a vessel equipped with a stirrer and there stirred for 24 hours (shearing step e)).

(22) The aqueous dispersion had the following characteristics: Solids content: 70% 30 wt % of the carbohydrates in the aqueous dispersion had a DP of 11 or more as measured via Gas Chromatography Viscosity: 12500 Pa.Math.s, whereby the viscosity measurement was done with a higher shear stress of 10 Pa (instead of 1.5 Pa) due to the high viscosity of the aqueous dispersion Stability: very stable No gel formation was observed, the aqueous dispersion wasand remainedpumpable