EP1594367A1

EP1594367A1 - Aleurone product and corresponding production method

Info

Publication number: EP1594367A1
Application number: EP04701568A
Authority: EP
Inventors: Josef Laux; Walter Von Reding; Gaspard Widmer
Original assignee: Buehler AG
Current assignee: Buehler AG
Priority date: 2003-02-20
Filing date: 2004-01-13
Publication date: 2005-11-16
Also published as: RU2005129280A; RU2335142C2; MXPA05008545A; WO2004073416A1; AU2004212654A1; CA2515342A1; WO2004073416B1; US20060177529A1; JP2006518195A

Abstract

The invention relates to an aleurone product comprising particles originating from the aleurone cells of cereal, in particular the aleurone cells of wheat. The invention is characterised in that the particles originating from the cereal aleurone cells are finely ground with a diameter of up to 500 νm as the longest dimension. The inventive aleurone product is produced as follows: preparation of bran, in particular wheat bran, which consists of aleurone constituents and non-aleurone constituents; separation of the aleurone constituents from the non-aleurone constituents to obtain a blend of aleurone constituents and non-aleurone constituents; adjustment of the humidity of the blend to achieve a value of 10-20 wt % water; and fine grinding (micro-grinding) of the blend by means of a friction roller mill comprising at least one roller pair, whose rollers are operated with different surface speeds and are pressed against one another.

Description

Aleuron product and process for its manufacture

The invention relates to an aleurone product which has particles consisting of cereal aleurone cells, in particular wheat aleurone cells, and a method for its production.

Aleuron is a nutritionally valuable component of the grain and especially the grain of wheat. Aleuron is present in the wheat grain in a single-cell layer (aleurone layer) between the flour body (endosperm) and the husk (Pericarp and Testa) of the wheat grain. The weight fraction of aleuron in wheat averages 8.3%.

Aleuron is isolated from bran using physical, in particular mechanical-abrasive and biological-enzymatic processes, and further processed. The bran used as the starting material for this is obtained in a conventional manner in a grain mill. For this purpose, reference is made to the international patent application WO 01/15711 A2 by the same applicant.

The aleurone cells of the wheat grain contain the nutritionally most important substances of the wheat grain in a concentrated form, such as vitamins, minerals, essential fatty acids, nutritional fibers, high-quality protein (albumin) and special protective substances (bioactive substances such as polyphenols, lignan, phytin, etc.). Wheat has also been a tried and tested food for humans and animals for several thousand years.

The high levels of vitamins and minerals contribute to general health as well as mental and physical performance.

The food fibers of aleuron contribute to better digestive activity in the large intestine (prebiotic). They also slow down through ion exchange Activity resorption in the small intestine and bind undesirable substances. They contribute to a long-lasting feeling of satiety and detoxification.

Bioactive substances of aleuron, such as polyphenols, flavonoids, lignan, beta-glucan, etc., have protective effects against a number of civilization diseases, such as hardening of the arteries and certain forms of cancer.

The invention has for its object to make the aleuron and its components usable for human and animal nutrition.

This is achieved according to the invention in that the aleurone product mentioned at the outset has finely ground particles consisting of cereal aleurone cells, the longest dimension of which is in the range from approximately an aleurone cell diameter to 500 μm. In this finely ground form, these aleuron-containing particles, particularly as an admixture to conventional foods, can be used in a particularly versatile manner for human and animal nutrition. Preferably, more than 50% of the particles consisting of aleuron cells have the longest dimension in the range from an aleuron cell diameter to 500 μm.

For certain applications, an even finer aleurone product is preferred. The longest dimension can then be in the range of 100-300 μm. The longest dimension is preferably in the range of 100-300 μm in the case of more than 50% of the particles consisting of aleuron cells. The longest dimension can also be in the range of 10-100 μm, with the longest dimension preferably also in the range of 10-100 μm for more than 50% of the particles consisting of aleuron cells.

According to the invention, cell groups consisting of 1 to 200 aleuron cells are contained among the particles consisting of aleuron cells, preferably more than 50% of the particles consisting of aleuron cells being cell groups consisting of 1 to 200 aleuron cells.

In the somewhat finer aleurone product, cell aggregates consisting of 5 to 100 aleuron cells are contained among the particles consisting of aleurone cells, whereby preferably more than 50% of its particles consisting of aleuron cells are cell assemblies consisting of 5 to 100 aleuron cells.

A special property of the aleurone product according to the invention is that the smallest dimension of the particles consisting of cereal aleurone cells corresponds approximately to the size of a single aleurone cell. In other words, the individual cells of the generally unicellular aleurone layer (wheat) are still intact. Through the fine grinding and the subsequent classification, only the size or the number of aleurone cells of the cell groups, also known as clusters, was determined.

Although aleuron is also found in the grains of other cereals, the aleurone cells from the bran of wheat are preferably used.

The bioavailability of the substances mentioned at the outset contained in the aleuron cells depends crucially on the condition of the cell walls of the aleuron cells in the cell assemblies according to the invention.

In a special version, the cell walls of all the aleuron cells of the particles are undamaged. This can be achieved by gentle fine grinding. This has the advantage that the cell content of the aleuron cells can be kept for a long time. Above all, oxidation of the cell components is prevented.

In an alternative embodiment, part of the aleurone cells of the particles have damaged cell walls. Preferably, less than 50% of the particle aleurone cells have damaged cell walls. This makes the valuable ingredients of the aleurone cells, which consist mainly of arabinoxylans, more accessible for digestion than in intact aleurone cells. In order to prevent premature oxidation of the cell contents, various antioxidants can be added to the aleurone product according to the invention if necessary.

The at least partial damage or weakening of the cell walls of the aleurone cells can take place enzymatically, chemically, mechanically or thermally. A combination These measures, for example mechanical-enzymatic or mechanical-thermal weakening of the cell walls, are also possible. Depending on the extent of the damage / weakening of the cell walls of the aleuron cells, humans or animals can absorb the nutritionally valuable substances mentioned at the outset faster or more completely or rather more slowly and less completely during digestion, with the prebiotic effect solely due to the im Digestive tract cells dominate. Through the targeted adjustment of the degree of damage to the aleuron cells, the release rate of the nutritionally valuable substances can be adjusted in a targeted manner. Heavily damaged aleurone cells lead to a quick and practically complete digestion of the cell contents, while the digestion (fermentation) of weakly damaged aleurone cells takes more time.

In a special embodiment, the aleurone product is a mixture of a first standard aurone product and a second standard aleurone product, the first standard aleurone product preferably having predominantly undamaged aleurone cells and the second standard aleurone product predominantly having damaged aleurone cells. This enables the production of a "tailor-made" aleurone product that can be adapted to the physiological needs of certain individuals (humans or animals).

The second standard aleurone product mainly contains destroyed aleurone cells or consists mainly of aleurone cell fragments.

The aleurone product according to the invention preferably has the following composition: 10-30% by weight protein, 5-15% by weight ash, 2-8% by weight fat and 30-60% by weight indigestible or only partially digestible fibers.

An important achievement of the present invention is that the aleurone product according to the invention has more than 90% by weight aleuron, in particular more than 95% by weight aleuron. A practically pure "aleurone powder" can also be provided according to the invention. In the case of a product according to the invention based on wheat bran, there are practically no longer any outer shell particles, which would cause the product to turn brown. Rather, this high-purity "aleurone powder" according to the present invention is approximately white or yellowish to white, and practically no brownish-dark shell particles are found in it.

In another embodiment, the aleurone product according to the invention can also have shell particles originating from the original bran in addition to aleurone cell groups. This product can be manufactured more cheaply with a little less effort.

The method according to the invention for producing the aleurone product has the following steps:

a) providing bran, in particular wheat bran, which consists of aleurone components and non-aleurone components; b) detaching the aleurone components from the non-aleuron components so that a mixture consisting of aleurone components and non-aleuron components is formed; c) adjusting the moisture of the mixture to a value of 10-20% by weight of water; d) Fine grinding of the mixture by means of a friction roller mill with at least one pair of rollers, the rollers of which are operated and pressed against one another at different surface speeds, so that the aleurone components are exposed to pressure and shear forces.

The mechanical stress on the aleurone particles in step d) makes the nutritionally valuable constituents of the aleurone cells more easily accessible for the digestion of the individual, and causes a change in the composition (dehydration) and taste (debittering) of the aleurone product.

In step c), the moisture is preferably adjusted to 14-16% by weight of water. Setting the moisture of the separated aleurone components to a value of 10-20% by weight and in particular to 14-16% by weight of water has a positive effect since it, in connection with the subsequent fine grinding, surprisingly leads to a taste improvement, especially to a debittering, of the aleuron.

It is particularly advantageous if, before step d), there is a step for separating the aleurone components from the mixture. If too many non-aleurone components, such as in particular shell particles, are contained in the mixture to be added to the fine grinding, the fine grinding is made difficult by the relatively hard foreign particles which act practically as "spacers" between the friction rollers and thus the actual aleuron particles (= Protect aleuron cell groups) from being crushed by the rollers.

This separation is preferably carried out electrostatically, and preferably before step c). The electrostatic separation of the aleurone components makes it possible to obtain a practically pure "aleurone powder" which not only can be better ground, but also looks more appealing than the brownish, finely ground product contaminated with shell particles.

In the case of fine grinding, the aleurone components are expediently passed through a pair of rollers for multiple friction grinding, or the aleurone components are passed through several successive roller pairs for repeated friction grinding, the roller gap being set practically to zero and the rollers being pressed against one another.

The step of fine grinding is preferably followed by a further step for separating out, preferably by means of a wet separation process of the finely ground (micro-ground) aleurone components. This allows e.g. win the fractions mentioned in the range 50-500 μm, in the range 100-300 μm or in the range 10-100 μm.

Further advantages, features and possible uses of the invention will become apparent from the following description of the description, which is not to be understood as restrictive Exemplary embodiments of the aleurone product according to the invention with reference to the drawing, in which:

1 shows a microscope image of predominantly undamaged aleurone cell associations according to the invention;

FIG. 2 shows an electron microscope image of the predominantly undamaged aleurone cell associations of FIG. 1 with a higher resolution;

FIG. 3 is a macroscopic picture, on which a mixture according to the invention of predominantly undamaged aleurone cell groups ("aleurone particles") and shell particles is shown;

FIG. 4 is a macroscopic image, on which a mixture according to the invention of barely undamaged aleurone cell groups ("aleurone particles"), but mainly of damaged aleurone cell groups ("aleuron slush") is shown.

1 shows a microscope image of predominantly undamaged aleurone cell associations 1, as are typically present after step b) of the method according to the invention. The aleuron cell groups 1 shown here each consist of a single-cell layer of aleuron cells 2 (see FIG. 2). These dressings each represent fragments that come from the single-celled aleurone layer between the shell and the flour body of a grain of wheat. The figure shows a fraction in which the longest dimension of the aleurone cell associations 1 is in the range of approximately 100-300 μm.

FIG. 2 shows an electron microscope image of the predominantly undamaged aleurone cell groups 1 from FIG. 1 with a higher resolution. Now the individual aleuron cells 2 and the cell walls 3 can also be clearly seen. The total of a few damaged aleuron cells 2 concentrate on the edge of the platelet-like aleurone cell associations 1, where the original, coherent, unicellular aleuron layer of a grain of wheat is typically separated in steps a) and b). was broke. The cell walls 3 of the aleurone cells 2 consist predominantly of arabinoxylanes and are difficult or impossible to break down or "crack" during digestion in humans and many animals. However, they are slowly fermented by bacteria in the digestive tract. The above-mentioned and other nutritionally valuable components are therefore available to the organism of the digestive human or animal to a limited extent.

FIG. 3 is a macroscopic image, on which a mixture according to the invention of predominantly undamaged aleurone cell groups ("aleurone particles") and shell particles is shown. In addition to a total of five aleurone cell groups 1, a shell particle 4 is also visible.

FIG. 4 is a macroscope image, on which a mixture according to the invention of barely undamaged aleurone cell groups ("aleurone particles"), but predominantly of damaged aleurone cell groups ("Aieuron mud") is shown. The damaged aleurone cell groups 5, in which a large part of the aleurone cells 2 (see FIG. 2) has broken open or burst and the cell contents of which have partially expired, now form an "aieuron slush", i.e. a mixture of a few cell groups 1, each with only a very few aleuron cells 2, from individual aleuron cells 2, from damaged cell groups and damaged aleuron cells, and from leaked cell contents (“aleuron juice”) of the damaged aleuron cells. The damaged or destroyed cell walls 3 of the aleuron cells 2, which mainly consist of arabinoxylans, now release a large part of the above-mentioned and other nutritionally valuable components of the aleurone cells, so that they are now available for digestion in humans and many animals, without the prebiotic Effect of the actual cell walls in the large intestine (fermentation of the arabinoxylans) is lost.

The bioavailability of nutritionally valuable components of the wheat grain increases gradually with the following forms of aleuron:

> Whole grain of wheat (whole grain)

> Peel detached from wheat grain with adhering layer of aleurone (whole bran) > Mixture of "aleurone particles" and shell particles "(crushed bran)

> finely ground aleurone particles ("Aieuron slush")

While the increase in bioavailability from 1) to 2), from 2) to 3) and from 3) to 4) is only relatively small, a significant increase in bioavailability could be achieved with the fine grinding according to the invention.

This is illustrated by Table 1: LEURON ^® , which shows a quantitative comparison between the aleuron presentation forms 3), 4) and 5).

Table 1: LEURO T

Legend:

3) Mixture of aleurone particles and shell particles

4) Pure aleurone particle powder

5) finely ground aleurone particles

Further typical compositions of aleuron preparations according to the invention are shown in Table 2. Table 2: Typical compositions of Aleuron preparations

Legend:

ASP-1: Aleuron product, which was manufactured as follows:

The starting point was wheat bran, which contains aleuron components and non-aleuron components.

The aleuron components were mechanically detached from the non-aleuron components so that a mixture of aleuron components and non-aleuron components was obtained.

The moisture of the mixture was then adjusted to a value of 10-20% by weight of water. The mixture prepared in this way was subjected to very fine grinding (micro-grinding) by means of a friction mill with at least one pair of rollers. The rollers were operated at different surface speeds and pressed together.

The product ASP-1 obtained in this way contains shell particles in addition to aleurone particles (associations of aleurone cells).

ASP-2: Aleuron product, which was manufactured as follows:

The starting point was ASP-1.

The ASP-1 has been enriched to increase the level of aleurone particles.

The necessary separation of shell particles was carried out by contact-electrical or triboelectric charging of ASP-1 and subsequent electrostatic separation of the shell particles from the aleurone particles.

The product ASP-2 obtained in this way has a high proportion of aleurone particles.

reference numeral

undamaged aleurone cell assembly ("aleurone particles") aleurone cell cell wall shell particles damaged aleurone cell assembly ("aieuron mud")

Claims

claims

1. Aleuron product, which consists of cereal aleurone cells, in particular wheat aleurone cells, consisting of particles, characterized in that the particles consisting of cereal aleurone cells are finely ground particles, the longest dimension of which is in the range from an aleurone cell diameter to 500 μm.

2. Aleuron product according to claim 1, characterized in that with more than 50% of its particles consisting of aleurone cells, the longest dimension is in the range from an aleurone cell diameter to 500 μm.

3. Aleuron product according to claim 1 or 2, characterized in that the longest dimension is in the range of 100-300 microns.

4. Aleuron product according to claim 3, characterized in that at more than 50% of the particles consisting of aleurone cells, the longest dimension is in the range of 100-300 microns.

5. Aleuron product according to claim 1 or 2, characterized in that the longest dimension is in the range of 10-100 microns.

6. Aleuron product according to claim 3, characterized in that at more than 50% of the particles consisting of aleurone cells, the longest dimension is in the range of 10-100 microns.

7. Aleuron product according to one of claims 1 to 6, characterized in that the particles consisting of aleurone cells are cell assemblies which consist of 1 to 200 aleurone cells.

8. Aleuron product according to claim 7, characterized in that more than 50% of its particles consisting of aleurone cells are cell assemblies which consist of 1 to 200 aleurone cells.

9. Aleuron product according to claim 7 or 8, characterized in that the particles consisting of aleurone cells are cell assemblies consisting of 5 to 100 aleurone cells.

10. Aleuron product according to claim 9, characterized in that more than 50% of its particles consisting of aleurone cells are cell assemblies which consist of 5 to 100 aleurone cells.

11. Aleuron product according to one of claims 1 to 10, characterized in that the smallest dimension of the particles consisting of cereal aleurone cells corresponds approximately to the size of a single aleurone cell.

12. Aleuron product according to one of claims 1 to 10, characterized in that the particles consisting of cereal aleurone cells are each formed by a single-cell layer of aleurone cells.

13. Aleuron product according to one of claims 1 to 12, characterized in that the aleurone cells come from the bran of wheat.

14. Aleuron product according to one of claims 1 to 13, characterized in that the cell walls of all aleurone cells of the particles are undamaged.

15. Aleuron product according to one of claims 1 to 14, characterized in that part of the aleurone cells of the particles have damaged cell walls.

16. Aleuron product according to claim 15, characterized in that in less than 50% of the aleurone cells of the particles have damaged cell walls.

17. Aleuron product according to claim 15 or 16, characterized in that it is a mixture of a first standard aleurone product and a second standard aleurone product.

18. Aleuron product according to claim 17, characterized in that the first standard aleurone product predominantly has undamaged aleurone cells and the second standard aleurone product predominantly has damaged aleurone cells.

19. Aleuron product according to claim 18, characterized in that the second standard aleurone product has mainly destroyed aleurone cells or consists mainly of aleurone cell fragments and leaked cell content.

20. Aleuron product according to claim 19, characterized in that the aleurone product is a pressing.

21. Aleuron product according to one of claims 15 to 20, characterized in that the damaged cell walls are enzymatically weakened cell walls.

22. Aleuron product according to one of claims 15 to 20, characterized in that the damaged cell walls are mechanically weakened cell walls.

23. Aleuron product according to one of the preceding claims, characterized in that it has 10-30% protein.

24. Aleuron product according to one of the preceding claims, characterized in that it has 5-15% by weight of ash.

25. Aleuron product according to one of the preceding claims, characterized in that it has 2-8% by weight of fat.

26. Aleuron product according to one of the preceding claims, characterized in that it has 30-60% by weight indigestible or only partially digestible fibers.

27. Aleuron product according to one of the preceding claims, characterized in that it has more than 95% by weight of aleurone.

28. Aleuron product, characterized in that it has more than 99% by weight of aleuron.

29. Aleuron product according to claim 27 or 28, characterized in that it also has shell particles in addition to aleurone cell groups.

30. A method for producing an aleurone product according to one of claims 1 to 29, which comprises the following steps:

a) providing bran, in particular wheat bran, which consists of aleurone components and non-aleurone components; b) detaching the aleurone components from the non-aleuron components so that a mixture consisting of aleurone components and non-aleuron components is formed; c) adjusting the moisture of the mixture to a value of 10-20% by weight of water; d) fine grinding (micro-grinding) of the mixture by means of a friction mill with at least one pair of rollers, the rollers of which are operated and pressed against one another at different surface speeds;

31. The method according to claim 30, characterized in that in step c) the moisture is adjusted to 14-16% by weight of water.

32. The method according to claim 30 or 3.1, characterized in that before step d) there is a step for separating the aleurone components from the mixture.

33. The method according to claim 32, characterized in that the separation takes place electrostatically, preferably before step c).

34. The method according to any one of claims 30 to 33, characterized in that in step d) the aleurone components are passed through a pair of rollers for repeated friction grinding several times.

35. The method according to any one of claims 30 to 34, characterized in that in step d) the aleurone components are passed through several successive pairs of rollers for repeated friction grinding.

36. The method according to any one of claims 30 to 35, characterized in that step d) is followed by a further step for separating out, preferably by means of a wet separation process, the finely ground (micro-calendered) aleurone components.

37. The method according to claim 36, characterized in that a fraction of cereal aleurone cells is discarded, the longest dimension of which is in the range from an aleurone cell diameter to 500 μm.

38. The method according to claim 36 or 37, characterized in that a fraction of cereal aleurone cells is separated out, the longest dimension of which is in the range 100-300 μm.

39. The method according to any one of claims 36 to 38, characterized in that a fraction of cereal aleurone cells is separated out, the longest dimension of which is in the range 10-100 μm.