METHOD FOR OBTAINING ONE OR MORE PROTEIN PREPARATIONS AND OIL FRACTIONS FROM SUNFLOWER SEEDS OR RAPE SEEDS

Abstract

In a method for obtaining one or more protein preparations and oil fractions from sunflower seeds or rape seeds, at least three fractions are provided or formed from the seeds, of which a first fraction has a shell content of <1 mass percent, a second fraction has a shell content of <20 mass percent or <10 mass percent, the shell content being greater than the shell content of the first fraction but equal to at least >0.3 mass percent or >0.15 mass percent, and a third fraction has a shell content of >60 mass percent or >30 mass percent. Oil is separated from the first fraction by means of one or de-oiling steps to a residual oil content of <3 mass percent, whereby one or more oil fractions and an oil-free first fraction are obtained as protein preparations. The method makes it possible to convert all of the fractions which are accumulated during the preparation of the sunflower seeds or rape seeds, into ingredients of the highest possible quality for food, animal feed, energy or technical applications.

Claims

1. Method for obtaining at least one protein preparation and several oil fractions from the seeds of sunflowers, which comprises at least the following steps: providing or forming at least three fractions from the seeds, of which a first fraction has a shell content of <1 mass percent, a second fraction has a shell content of <20 mass percent, which is greater than the shell content of the first fraction, but is at least >0.3 mass percent, and a third fraction has a shell content of >60 mass percent, separating oil from the first fraction through one or more de-oiling steps down to a residual oil content of <3 mass percent, with the result that one or more oil fractions and an oil-free first fraction as a first protein preparation are obtained, and separating oil from the second fraction, with the result that one or more further oil fractions are obtained.

2. Method for obtaining at least one protein preparation and several oil fractions from rape seeds, which comprises at least the following steps: providing or forming at least three fractions from the seeds, of which a first fraction has a shell content of <1 mass percent, a second fraction has a shell content of <10 mass percent which is greater than the shell content of the first fraction, but is at least >0.15 mass percent, and a third fraction has a shell content of >30 mass percent, separating oil from the first fraction through one or more de-oiling steps down to a residual oil content of <3 mass percent, with the result that one or more oil fractions and an oil-free first fraction as a first protein preparation are obtained, and separating oil from the second fraction, with the result that one or more further oil fractions are obtained.

3. Method according to claim 1, characterized in that forming the at least three fractions comprises the following steps: shelling the seeds and removing a part of the shells by sieving and/or winnowing and/or sorting in such manner that the at least three fractions are obtained with the stated shell contents.

4. Method according to claim 1, characterized in that one or more further fractions is/are provided or formed that contain proteins from the kernels of the sunflower seeds or rape seeds, and from which oil and a protein-containing residue are then recovered, each having a protein content which is greater than a protein content of the shells.

5. Method according to claim 1, characterized in that the separation of oil from the first fraction is carried out by mechanical partial de-oiling of the first fraction to obtain a first oil fraction and a first residue fraction, und subsequent solvent extraction once or multiple times from the first residue fraction.

6. Method according to claim 5, characterized in that the mechanical partial de-oiling is carried out at an average temperature of the first fraction below 80° C. for the duration of the mechanical partial de-oiling to reach an oil content of >10 mass percent and <30 mass percent.

7. Method according to claim 1, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the first fraction contains between 1 and 80%, advantageously between 5 and 35%, particularly advantageously between 15 and 25% of the quantity of kernels that are present in the starting material for the method.

8. Method according to claim 1, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the third fraction has a shell content of >80 mass percent and <99 mass percent, advantageously <90 mass percent in the case of seeds from sunflowers and a shell content of >60 mass percent and <99 mass percent, advantageously <90 mass percent in the case of seeds from rape.

9. Method according to claim 1, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the first fraction has a shell content von <0.5 mass percent, advantageously <0.1 mass percent.

10. Method according to claim 1, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the second fraction has a shell content of <10 mass percent in the case of seeds from sunflowers, and a shell content <5 mass percent in the case of seeds from rape.

11. Method according to claim 1, characterized in that the separation of oil from the first fraction is carried out through the one or several de-oiling steps until a residual oil content of <2 mass percent is reached.

12. Method according to claim 1, characterized in that through the one or more de-oiling steps, oil is separated from the second fraction until a residual oil content of <10 mass percent, advantageously <3 mass percent is reached, as a result of which the one or more further oil fractions and an oil-free second fraction as a second protein preparation are obtained.

13. Method according to claim 12, characterized in that the separation of oil from the second fraction is carried out by mechanical partial de-oiling of the second fraction.

14. Method according to claim 12, characterized in that the separation of oil from the second fraction is carried out by mechanical partial de-oiling of the second fraction in order to obtain a second oil fraction and a second residue fraction, followed by solvent extraction once or multiple times from the second residue fraction.

15. Protein preparation from sunflower seeds which is obtained as a first protein preparation by the method according to claim 1 and has a protein content of less than 90 mass percent relative to the dry mass, advantageously less than 80 mass percent, particularly advantageously less than 70 mass percent, a lightness value L* according to CIE-L*a*b*-colorimetry of at least 70, advantageously >80, a water-binding capacity of >1 ml/g dry mass, preferably >2 ml/g dry mass, an oil-binding capacity of >0.5 ml/g dry mass, preferably >1 ml/g dry mass, an emulsifying capacity of >300 ml/g dry mass, preferably >400 ml/g dry mass, particularly preferably >500 ml/g dry mass, and a protein solubility of more than 25%, particularly preferably more than 40%.

16. Protein preparation from rape seeds which is obtained as a first protein preparation by the method according to claim 2 and has a protein content of less than 90 mass percent relative to the dry mass, advantageously <70 mass percent, a lightness value L* according to CIE-L*a*b*-colorimetry of >70, advantageously >80, a water-binding capacity of >1 m/g dry mass, preferably >2 ml/g dry mass, particularly preferably >3 ml/g dry mass, an oil-binding capacity of >0.5 ml/g dry mass, preferably >1 ml/g dry mass, an emulsifying capacity of >300 ml/g dry mass, preferably >500 ml/g dry mass, particularly preferably >600 ml/g dry mass, and a protein solubility of more than 30%, particularly preferably more than 60%.

17. Method according to claim 2, characterized in that forming the at least three fractions comprises the following steps: shelling the seeds and removing a part of the shells by sieving and/or winnowing and/or sorting in such manner that the at least three fractions are obtained with the stated shell contents.

18. Method according to claim 2, characterized in that one or more further fractions is/are provided or formed that contain proteins from the kernels of the sunflower seeds or rape seeds, and from which oil and a protein-containing residue are then recovered, each having a protein content which is greater than a protein content of the shells.

19. Method according to claim 2, characterized in that the separation of oil from the first fraction is carried out by mechanical partial de-oiling of the first fraction to obtain a first oil fraction and a first residue fraction, und subsequent solvent extraction once or multiple times from the first residue fraction.

20. Method according to claim 19, characterized in that the mechanical partial de-oiling is carried out at an average temperature of the first fraction below 80° C. for the duration of the mechanical partial de-oiling to reach an oil content of >10 mass percent and <30 mass percent.

21. Method according to claim 2, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the first fraction contains between 1 and 80%, advantageously between 5 and 35%, particularly advantageously between 15 and 25% of the quantity of kernels that are present in the starting material for the method.

22. Method according to claim 2, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the third fraction has a shell content of >80 mass percent and <99 mass percent, advantageously <90 mass percent in the case of seeds from sunflowers and a shell content of >60 mass percent and <99 mass percent, advantageously <90 mass percent in the case of seeds from rape.

23. Method according to claim 2, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the first fraction has a shell content von <0.5 mass percent, advantageously <0.1 mass percent.

24. Method according to claim 2, characterized in that the provision or formation of the at least three fractions from the seeds takes place in such manner that the second fraction has a shell content of <10 mass percent in the case of seeds from sunflowers, and a shell content <5 mass percent in the case of seeds from rape.

25. Method according to claim 2, characterized in that the separation of oil from the first fraction is carried out through the one or several de-oiling steps until a residual oil content of <2 mass percent is reached.

26. Method according to claim 2, characterized in that through the one or more de-oiling steps, oil is separated from the second fraction until a residual oil content of <10 mass percent, advantageously <3 mass percent is reached, as a result of which the one or more further oil fractions and an oil-free second fraction as a second protein preparation are obtained.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In the following text, the suggested method will be explained again, in greater detail, with reference to exemplary embodiments and in conjunction with the drawings. In the drawings:

[0041] FIG. 1 is a schematic diagram of an exemplary configuration of the method for the preparation of sunflower seeds; and

[0042] FIG. 2 is a schematic diagram of an exemplary configuration of the method for the preparation of rape seeds.

EXEMPLARY EMBODIMENTS

Example 1

[0043] In this example, as represented schematically in FIG. 1, three fractions were recovered using an impact dehuller followed by several sieving, winnowing and sorting cycles from sunflower seeds that had been cleaned of contaminants as far as possible:

[0044] 25 mass percent of an ultrapure first fraction, referred to hereafter as kernel fraction (1), with a shell content of <0.1 mass percent,

[0045] 20 mass percent of a second fraction, referred to hereafter as kernel fraction (2), with a shell content of 10 mass percent,

[0046] 10 mass percent of a third fraction, referred to hereafter as kernel fraction (3), with a shell content of 30 mass percent, and

[0047] 30 mass percent of a shell fraction, which had a shell content of 80 mass percent.

[0048] Kernel fraction (1) was pressed at moderate temperatures (<60° C.) until a residual oil content of 18 mass percent was reached. After filtration, the oil obtained was a very mild, nutty flavoured cooking oil with yellowish colour, and which could be used as cooking oil after particles causing cloudiness were separated.

[0049] The press cake was de-oiled with hexane and desolventised at low temperatures below 80° C. Then, the solid material was ground to analytical fineness (particle size predominantly <100 μm) in a laboratory mill and evaluated with regard to colour and functional properties.

[0050] The protein flour thus obtained as the first protein ingredient (1P) had a protein content relative to TS of 59% (factor 6.25), a remaining oil proportion of 2% and presented a lightness value L* of 85 according to CIE L*a*b*. It had a neutral, slightly nutty flavour. The protein of the preparation was 40% soluble at pH 7 and presented an emulsifying capacity of 480 ml per gram protein. Accordingly, as a highly functional food additive this fraction is clearly usable in many applications with stringent requirements.

[0051] Kernel fraction (2) was pressed at 90° C. until an oil content of 10 mass percent was reached. After filtration, the oil obtained had a slightly bitter taste and a slightly cloudy appearance with yellowish colour. It can be treated further in a refinement process to produce a cooking oil.

[0052] The press cake from this pressing was also de-oiled with hexane and desolventised in the drying cabinet at a temperature of 110° C. Then, the solid material was ground to analytical fineness (particle size predominantly <100 μm) in a laboratory mill and evaluated with regard to colour and functional properties.

[0053] The protein flour thus obtained as the second protein preparation (2P) had a protein content relative to TS of 54% (factor 6.25), a residual fat content of 1.8% and presented a lightness value L* of 68 according to CIE L*a*b*. It had a mildly bitter flavour and left a rough feeling in the mouth. The protein of the flour was 25% soluble at pH 7 and presented an emulsifying capacity of 320 ml per gram. Accordingly, is not suitable for use as an ingredient in human food, but is certainly usable in high-standard animal feed applications, for example in fish food or pet food.

[0054] Kernel fraction (3) was also processed similarly to kernel fraction (2). Due to the high shell content, the oil was still darker, and slightly more bitter, so it was essential for the fraction to undergo refining.

[0055] The protein flour thus obtained as the third protein ingredient (3P) had a protein content relative to TS of 39% (factor 6.25), a residual fat proportion of 1.7% and presented a lightness value L* of 40 according to CIE L*a*b*. It had a bitter flavour and caused a very rough feeling in the mouth. The protein of the flour was 255 soluble at pH 7 and presented an emulsifying capacity of 250 ml per gram. Accordingly, this fraction only lends itself for use in simple animal feed applications e.g., for cattle.

[0056] The shell fraction thus obtained consisted mainly (approx. 80%) of shells and some remaining kernel pulp, and was not examined further; the oil fractions recovered after de-oiling with hexane were also not further analysed.

Example 2

[0057] In this example, as represented schematically in FIG. 2, three fractions were recovered using an impact dehuller followed by several sieving, winnowing and visual and manual sorting cycles from rape seeds that had been cleaned of contaminants as far as possible:

[0058] 35 mass percent of an ultrapure first fraction, referred to hereafter as kernel fraction (1), with a shell content of <1 mass percent,

[0059] 30 mass percent of a second fraction, referred to hereafter as kernel fraction (2), with a shell content of 8 mass percent,

[0060] 20 mass percent of a third fraction, referred to hereafter as kernel fraction (3), with a shell content of 20 mass percent, and

[0061] 15 mass percent of a shell fraction, which had a shell content of 60 mass percent.

[0062] Kernel fraction (1) was pressed at moderate temperatures (<60° C.) until a residual oil content of 22 mass percent was reached. After filtration, the oil obtained was a very mild tasting, clear cooking oil with yellow colour, and faint note of mustard.

[0063] The press cake was de-oiled with ethanol and desolventised at low temperatures below 90° C. Then, the solid material was ground to analytical fineness (particle size predominantly <100 μm) in a laboratory mill and evaluated with regard to colour, sensory impressions and functional properties.

[0064] The protein flour thus obtained as the first protein preparation (1P) had a protein content relative to TS of 58% (factor 6.25), a remaining fat proportion of 1.8% and presented a lightness value L* of 80 according to CIE L*a*b*. It had a neutral, slightly tangy flavour with faint note of mustard. The protein of the preparation was 55% soluble at pH 7 and presented an emulsifying capacity of 610 ml per gram protein. Accordingly, as a highly functional food additive this fraction is usable in many spicy applications.

[0065] Kernel fraction (2) was pressed at 90° C. until an oil content of 12 mass percent was reached. After filtration, the oil obtained had a slightly bitter taste and a slightly cloudy appearance with yellow colour. It can be treated further in a refinement process to produce a cooking oil.

[0066] The press cake from this pressing was de-oiled with hexane and desolventised in the drying cabinet at a temperature of 110° C. Then, the protein was ground to analytical fineness (particle size predominantly <100 μm) in a laboratory mill and evaluated with regard to colour and functional properties.

[0067] The protein flour thus obtained as the second protein preparation (2P) had a protein content relative to TS of 51% (factor 6.25), a residual fat content of 2% and presented a lightness value L* of 65 according to CIE L*a*b*. It had a mildly bitter flavour and left a rough feeling in the mouth. The protein of the flour was 25% soluble at pH 7 and presented an emulsifying capacity of 370 ml per gram. Accordingly, this fraction is not suitable for use as an ingredient in human food, but is certainly usable in animal feed applications, for example in poultry feed.

[0068] Kernel fraction (3) was also processed similarly to kernel fraction (2). Due to the high shell content and harsh processing conditions, the oil was still darker, and slightly more bitter.

[0069] The protein flour thus obtained as the third protein preparation (3P) had a protein content relative to TS of 37% (factor 6.25), a residual fat proportion of 1.8% and presented a lightness value L* of 35 according to CIE L*a*b*. It had a bitter flavour and caused a very rough feeling in the mouth. The protein of the flour was 25% soluble at pH 7 and presented an emulsifying capacity of 250 ml per gram. Accordingly, this fraction only lends itself for use in simple animal feed applications e.g., for cattle.

[0070] The shell fraction obtained consisted mainly (approx. 60%) of rapeseed shells and some remaining kernel pulp. As with the sunflower shell fraction, it was not examined further; the same also applied for the oil fractions recovered after de-oiling with solvent.

[0071] In the present patent application, the following determination procedures were used for the quantitative determination of the properties and values declared:

[0072] Protein Content: [0073] The protein content is defined as the content that is calculated from the nitrogen determination multiplied by the factor 6.25. The protein content is expressed for example as a percentage relative to the dry mass (TS).

[0074] Colour: [0075] The perceptible colour is determined using CIE-L*a*b*-colorimetry (see DIN 6417). In this context, the L*-axis indicates the lightness, wherein black has the value 0 and white has the value 100, the a*-axis describes the green or red component, and the b*-axis describes the blue or yellow component.

[0076] Protein Solubility: [0077] Protein solubility is determined using determination methods according to Morr et al. 1985 (see journal article: Morr C. V., German, B., Kinsella, J. E., Regenstein, J. M., Van Buren, J. P., Kilara, A., Lewis, B. A., Mangino, M. E, “A Collaborative Study to Develop a Standardized Food Protein Solubility Procedure. Journal of Food Science”, volume 50 (1985) pages 1715-1718). The protein preparation is suspended in a 0.1 M NaCl-solution at room temperature in a mass volume percentage from 1:25 to 1:50 (w/v) (i.e. 1-2 g of the protein preparation to 50 ml solution), and maintained for about 60 min at a pH 7 using 0:1 M HCl-solution or NaOH-solution, and stirred at about 200 rpm, and the insoluble sediment is subsequently centrifuged for 15 minutes at 20,000 times the acceleration of the Earth (20,000 g). The protein solubility may be stated in percent, for example, wherein a protein solubility of x % means that x % of the protein present in the preparation will be present in the clarified supernatant is the described method is used.

[0078] Water Binding: [0079] The water-binding capacity is determined by means of the AACC determination procedure as defined in: American Association of Cereal Chemists, “Approved methods of the AACC”. 10th ed., AACC. St. Paul, Minn., 2000b; Method 56-20. “Hydration capacity of pregelatinized cereal products”. The water-binding capacity can be stated for example in ml/g, i.e. millilitres of bound water per gram of preparation, and is determined according to the AACC determination procedure using the weight of the sediment saturated with water minus the weighed in amount of the dry preparation after mixing approx. 2 g protein preparation with approx. 40 ml water for 10 minutes and centrifuging at 1000 g for 15 minutes at 20° C.

[0080] Oil Binding: [0081] The oil-binding capacity is determined using a determination method as described in: Ludwig I., Ludwig, E., Pingel B., “Eine Mikromethode zur Bestimmung der Fettbindekapazität [A micromethod for determining fat-binding capacity]”. Nahrung/Food, 1989, 33(1), 99. [0082] The oil-binding capacity can be stated in ml/g, for example, i.e. millilitres of bound oil per gram of preparation, and is measured according to the abovementioned determination procedure as the volume of the oil-binding sediment after mixing 1.5 g protein preparation with 15 ml maize-germ oil for 1 minute and centrifuging at 700 g for 15 minutes at 20° C.

[0083] Emulsifying Capacity: [0084] The emulsifying capacity is determined by means of the “conductivity measurement method”, in which 100 ml of maize germ oil, pH 7, is added to a 1% suspension of the protein preparation until phase inversion of the oil-in-water emulsion. The emulsifying capacity is defined as the maximum oil absorption capacity of said suspension, determined on the basis of the spontaneous fall in conductivity upon phase inversion (see journal article by Wäsche, A., Müller, K., Knauf, U., “New processing of lupin protein isolates and functional properties”. Nahrung/Food, 2001, 45, 393-395) and may be expressed for example in ml oil/g, i.e. millilitres of Emulsified Oil Per Gram Protein Preparation.

[0085] Residual Oil Content: [0086] The residual oil content is determined using Soxhlet Method AOAC 963.15, i.e. by gravimetric determination following Soxhlet extraction.