KR20010095469A - Processing of flaxseed - Google Patents

Abstract

PURPOSE: A method for processing flaxseed containing removing the hulls from a seed core of flaxseed and separating the outer and inner part of the hulls into a mucilage fraction and a fiber fraction respectively is provided. Whereby a food enhancer having a little influence on a taste and flavor of foodstuffs is produced. CONSTITUTION: The hulls of flaxseed are removed from a seed core by grinding. The outer part of hulls removed firstly is separated into a mucilage fraction, while the inner part thereof is separated into a fiber fraction containing large amount of lignans. The separated mucilage fraction occupies 3 to 10% by weight of seed weight and the separated fiber fraction occupies 20 to 70% by weight thereof. In addition, oil is separated from the fiber fraction by extraction and a protein part and a hydrocarbon part of the seed core are separated from the residues remaining after oil separation.

Description

Flaxseed processing method {PROCESSING OF FLAXSEED}

The present invention relates to a linseed ( Linum species) treatment method for the production of food fortification.

Flaxseed husks are anatomically composed of three parts. The outer part is composed of water-soluble mucus and epithelial layer. Below the mucus is the spermoderme, a substantial shell material consisting of four layers. The endothelial surface is an endosperm, and the seed core consists of cotyledon and accounts for about half of the seed weight. The main part of the seed oil and protein is located in this cotiledone. Seeds have been used in animal feed and human nutrition in their own or in powder form. In addition, mucus isolated from the shell has been used in medicine and cosmetics.

In addition, efforts have been made to peel the flaxseeds and separate the shells from the inner parts of the seeds (Wanasundra & Shahidi, Food Chem, 59 47-55 (1997)). However, peeling not only required a lot of hands, but also was a difficult task, mainly due to the shape of the seed. Abrasive method was used for peeling.

The oil can be separated from flaxseed by pressing or extraction. Solid residues have been used primarily in animal feed. Solid residues have generally been considered unsuitable for foodstuffs (Oomah & Mazza, Food Chem, 48 109-114 (1993)), but have been used nonetheless, especially for bread products. The use of solid residues is extremely limited due to unpleasant odor changes and color changes.

Flaxseed also contains 80 to 370 mg / 100 g of lignans (Mazur et al., Anal. Biochem., 233, 169-180 (1996)]. Nutritionally, lignans have been found to provide health benefits, in particular anticancer effects.

Currently, methods have been developed to remove the bark layer from the whole flaxseed and then divide the bark into the first stripped mucus pieces and the second stripped fiber pieces. The slime fragment includes an outermost shell layer and is rich in water-dispersible carbohydrate (mucus). Fibrous pieces contain an inner shell layer, particularly rich in fibers and lignans. Polishing can be carried out using mills, in particular mills equipped with millstones.

The peel removal method of the present invention provides a separate separation fragment suitable for use in other applications in a one step operation.

In addition, a method has been developed in which the flaxseed solid material obtained by separating oil from seeds is treated with a mixture of water and alcohol to bleach. The bleach mixture may further contain hydrogen peroxide. In addition, shells or bark fragments isolated from the complete seed can be bleached by the bleaching method of the present invention.

The bleaching method of the present invention provides a product for use as a food fortification, which has less variation in color and aroma than conventional untreated solid materials.

The outermost flaxseed layer mainly contains water-soluble carbohydrates and forms flaxseed mucus. Below the outermost flaxseed layer is a layer that contains mainly fiber. If unbroken complete flaxseed is ground, the outer layer is first removed. This layer is separated into mucus pieces. The inner layer is then removed, which is removed into the fiber pieces. The debris is also rich in lignans. The residue includes the inner part of the seed, which is rich in oils and proteins. The inner part accounts for about half of the seed weight.

Mucus slices can be used in foodstuffs, for example, in bread, mucus slices act as thickening agents in particular. In addition, the slime piece can be used for cosmetics and pharmaceuticals. The rheological properties of the mucus pieces are similar to those of the gum arabic.

The slime pieces account for about 0.5-10%, for example 5-8%, of the seed weight. The slime piece is removed together with the inner part of the shell.

Fibrous pieces can be used as food reinforcements, especially as food enhancers where an increase in fiber and lignans is desired. Lignan has been shown to provide health benefits. Lignan appears to act as an anticancer agent, among other actions. Naturally, the fiber pieces contain a certain amount of oil. This oil can for example be removed with hexane. In addition, debris that is particularly rich in fiber can be separated from the fiber pieces. The lignan concentrate can be obtained from the fiber pieces, in particular when the oil is first removed, for example using screening or grading. The lignan can also be concentrated by extraction.

The fiber pieces comprise about 20 to 70% of the weight of the seed, for example 30 to 50%, in particular 35 to 45%.

The oil can be separated from the inside of the seed, and the residue is enriched in protein. Particularly high protein content, ie up to 70% protein fraction and mucus fragments can be further separated from the residue.

Grinding is carried out to keep the inside of the seed as completely as possible to separate the inside of the seed from the ground powder. Polishing can be performed using a generally used polishing apparatus. This device may for example be a modified rice mill. Grinding is carried out so that the shell part is separated as completely as possible with only minimal internals removed. Polishing can be carried out in a continuous process.

Seeds can be ground, for example, by mills equipped with millstones. The rough surface of the millstone polishes the seeds at a predetermined rate, preferably for about 1 to 3 minutes. The ground powder was found to have a particularly high lignan content after a polishing period of about 1 minute.

The fiber piece is a brown powder. It can be bleached and at the same time it can be degreased and degreased to improve quality.

During bleaching, the powder is wetted with water, where the ratio of water to powder varies, for example, in the range of 1: 1 to 3: 1. Enzymes such as lipases or proteases can be added to the water. Water can be allowed to act for example for 0.5 to 12 hours, and then the paste is homogenized in alcohol, for example C1-C5 alcohol, in particular ethanol or isopropanol, especially isopropanol. The amount of alcohol is, for example, 2 to 5 times the amount of powder. The homogenized alcohol-containing suspension is separated from the solution using filtration or centrifugation. The separated powder is preferably washed with, for example, 2-6 times the amount of alcohol, followed by filtration or centrifugation of the suspension. The alcoholic portion is dried at 20 to 90 ° C., for example. The dried paste is ground or granulated to a desired particle size as necessary.

The alcohol weakens the viscosity formed by the alcohol insoluble carbohydrate component except the water soluble carbohydrate component. This not only facilitates homogenizing the paste into a non-viscous suspension but also facilitates mechanical separation treatment of the suspension, for example filtration and centrifugation. Water treatment opens the solid structure, whereby most of the residual oil in the paste is removed during the water-alcohol treatment. The finer the powder ground, the stronger the effect. The alcohol added after the water treatment precipitates the water soluble carbohydrates and contributes to the separation from the surrounding matrix. This makes it possible for example to concentrate the dry product into the water soluble component by mechanical means such as grading.

Bleaching also removes cyanogen from the product.

Better results than those obtained by simple water-alcohol treatment are obtained by adding, for example, 2-7% hydrogen peroxide to the aqueous solution in the washing step. Hydrogen peroxide added prior to alcohol treatment effectively separates the mucus from the surface.

Prior to bleaching, the powder may be heat treated to inactivate any enzymatic activity that affects flavor. Temperature range is 40-80 degreeC, for example, and processing time is 0.5 to 2 hours, for example. The treatment may be performed under vacuum. In addition to inactivating enzymes, temperature and possible vacuum provide an associated effect on the removal of low molecular weight compounds that affect taste.

Solid residues remaining after the oil has been separated from complete flaxseed (flax seed grouts), in particular those obtained by compression can also be bleached by the process of the invention. It is preferable to grind the grout before bleaching, for example using a diamond mill grinder equipped with a pair of millstones.

Example 1

Flaxseed was polished using an apparatus designed for oat polishing. Seeds were ground between a millstone and a metal mesh in a batch unit equipped with two millstones (each batch: 80 g). At the end of the polishing, seeds were removed from the apparatus through hatches at the bottom of the mesh. During the treatment, the ground powder was transferred through the mesh into the receiver. Table 1 below shows the yield of polished debris and protein, fat and lignan concentrates as a function of year-end time.

Calculated protein, fat and lignan concentrations based on ground linseed ( Linum usitatissimum, Helmi ssp. ) Powder yield and dry matter Polishing time (minutes) Protein (% dry matter) Fat (% of dry matter) Lignan (mg / 100g) yield(%) One 12 18 1480 4 2 15 27 1360 9 3 17 29 1230 12 4 18 31 1070 16 5 19 34 1070 18 6 19 34 960 21 7 19 36 1030 22 8 20 36 800 24

The powder obtained can be used as reactant in further lignin concentration. By extracting the oil from the ground powder, for example by hexane extraction, the lignan concentration of the powder will increase to the same amount as the oil content, ie 18% after 1 minute of polishing. The powder can be further bleached, for example as described in Example 2 below.

Example 2

The flaxseed grout obtained by cold extraction was bleached. The grout was heat treated to inactivate any enzymatic activity affecting the flavor of the grout. The best meaningful results were obtained by heat treatment for 1 hour at 60 ° C. vacuum. The resulting dark brown grout was washed with water at room temperature to form a paste like powder. After settling for about 0.5 to 2 hours, the paste-like powder was washed in isopropanol at a ratio of 1.2 to 3 (w / w). The resulting ground flaxseed suspension was filtered in vacuo. The resulting deposit, ie, the filter press cake, was washed during the homogenization process in isopropanol and re-filtered in vacuo or centrifuged using decantation centrifugation. The filtered powder was dried at room temperature or dried using a closed drying technique to recover isopropanol.

Better results than those obtained only by water-alcohol treatment were obtained by adding hydrogen peroxide to the aqueous solution in the washing step. The grout was washed in an aqueous solution with a hydrogen peroxide content of 4 to 5% to give a very bright powder. After washing for 0.5 to 2 hours, the paste-like powder was homogenized in twice the isopropanol, filtered in vacuo, then washed in isopropanol and refiltered. The filtered powder was dried.

In particular, protein-rich products were obtained when 50% of the solution was taken up by isopropanol and about 5% of the solution by hydrogen peroxide.

According to the flaxseed processing method of the present invention, it is possible to prepare a food enhancer having less influence on taste and aroma of food.

Claims (19)

A method of removing flaxseed hulls from a seed core, wherein the outer part of the first removed shell is separated by a mucus piece, and the second part is then separated by a fiber piece. 2. The method of claim 1, wherein the separated slime pieces comprise 3 to 10%, for example 5 to 8%, of the seed weight. 3. Process according to claim 1 or 2, characterized in that the separated fiber pieces comprise 20 to 70%, for example 30 to 50%, in particular 35 to 45% of the seed weight. The method according to any one of claims 1 to 3, further comprising separating the fiber piece richer in fiber from the fiber piece. The method according to any one of claims 1 to 4, wherein the lignan-rich lignan fragments are further separated from the fiber pieces. 6. The process according to claim 1, wherein the oil is separated from the fibrous piece, in particular by extraction. 7. The method according to any one of claims 1 to 6, wherein the oil is separated from the inner portion remaining after grinding. 8. The method of claim 7, wherein the protein portion and the carbohydrate portion of the seed core are separated from residues remaining after oil separation. 9. The method according to claim 1, wherein the polishing is performed in a mill equipped with a millstone. The method according to any one of claims 1 to 9, wherein the separated fiber pieces are bleached. The method of claim 10, wherein the bleaching is performed using a bleach solution containing water and alcohol. Process according to claim 11, characterized in that the alcohol is a C1-C5 alcohol, for example ethanol or isopropanol, in particular isopropanol. The method according to claim 11 or 12, wherein the amount of the alcohol is 2 to 5 times the amount of the fiber pieces. The process according to claim 11, wherein the bleach solution further contains 2 to 7%, for example 4 to 6%, in particular about 5%, hydrogen peroxide. The method according to claim 11, wherein the fiber piece is treated with an aqueous solution, for example for 0.5 to 12 hours, before treating with the bleach solution. The method of claim 15 wherein said aqueous solution contains enzymes such as lipases or proteases. The process according to claim 15 or 16, wherein the sludge obtained from the water treatment is mixed with the alcohol to carry out bleaching. 18. The method of claim 14 or 17, wherein hydrogen peroxide is added to the aqueous solution. 19. The method according to any one of claims 10 to 18, characterized in that, before bleaching the fiber piece, for example at a temperature of 40 to 80 ° C, for example for 0.5 to 2 hours, in particular in a vacuum How to.