HK1076357B - Complex - Google Patents

Description

Composite body

Technical Field

The present invention relates to a complex of phytosterol and egg yolk lipoprotein, which is useful as a food material, and a method for producing the same.

Background

Phytosterols and their saturated forms of phytostanols are known to reduce blood total cholesterol levels as well as low density lipoprotein-cholesterol levels and are also known to be safe as food products. Phytosterols are contained in vegetable fats and oils, soybeans, wheat, and the like, and are taken every day, and their intake amount is small, so that it has been desired to use phytosterols as food materials in particular in recent years.

However, phytosterol is solid at room temperature (melting point is about 140 ℃), does not dissolve in water, and does not easily dissolve in oily components, and if only phytosterol powder is simply added to various foods, the particles of the phytosterol powder agglomerate with each other, thus causing a problem of rough mouthfeel of the foods. Therefore, various methods for food have been sought.

For example, in order to obtain an oil-in-water type emulsion such as mayonnaise containing phytosterol, it has been proposed to obtain an emulsion by dissolving phytosterol in oil and fat as an oil phase, forming an aqueous phase from the enzyme-treated egg yolk and water, and mixing the aqueous phase with the oil phase while stirring (patent document 1), to obtain an oil-in-water type emulsion composition by heating phytosterol, phospholipid (lecithin), polyol, water and ethanol, stirring them uniformly, and slowly adding edible oil and fat thereto (patent document 2), to obtain such a complex by dissolving phospholipid and sterol in an organic solvent, and simultaneously precipitating phospholipid and sterol by removing the organic solvent, to obtain such a complex, and to use such a complex as an emulsifier (patent document 3).

Patent document 1: japanese unexamined patent application publication No. 2002-171931

Patent document 2: japanese unexamined patent application publication No. 2001-117

Patent document 3: japanese unexamined patent publication No. Hei 4-149194

Disclosure of Invention

However, in the method of dissolving phytosterol in fats and oils to obtain an emulsion (patent document 1) and the method of slowly adding fats and oils to a mixture of phytosterol, phospholipid, polyol, water and ethanol (patent document 2), the use of fats and oils as a precursor cannot be used in foods containing almost no fats and oils such as aqueous beverages.

Further, the method using a complex obtained from phytosterol and phospholipid (patent document 3) has a problem that such a complex cannot be obtained by simply mixing phytosterol and phospholipid, and in order to produce such a complex, it is necessary to remove the organic solvent immediately after dissolving phytosterol and phospholipid in the organic solvent, and therefore a spray drying apparatus that vaporizes the solvent under vacuum is used. This device has a problem of high production cost of the composite because it is explosion-proof and has a large scale. Moreover, the relative phospholipid content of phytosterols in this complex is relatively high. Therefore, if it is desired to increase the phytosterol content in the food, the phospholipid content is also increased and the good taste of the phospholipids is affected by the taste of the food.

In contrast, the present invention has an object that a desired amount of phytosterol can be added without impairing the taste of the food even in an aqueous food or an emulsified food, and that the food to which the phytosterol is added exhibits a smooth mouthfeel free from the rough feeling derived from the phytosterol.

The present inventors have learned that: (i) the egg yolk and the powdery phytosterol are stirred and mixed in the aqueous medium, and are uniformly dispersed, (ii) in this case, if the dilution ratio of the egg yolk during stirring and mixing is high, the egg yolk is left to stand after stirring and mixing, and the phytosterol floating on the water surface before stirring and mixing is precipitated, (iii) the precipitates do not aggregate with each other and exhibit a smooth and non-rough mouthfeel, and when the precipitates are separated and dried and re-dispersed in the aqueous medium, the dispersibility is remarkably improved, and even in the supernatant of the stirred mixture in which the precipitates are generated, the egg yolk lipoprotein present in the original egg yolk is not found, and the precipitates are considered to be a complex of the phytosterol and the egg yolk lipoprotein, (iv) the complex is prepared by mixing 4 to 185 parts by weight of the phytosterol with respect to 1 part by weight of the egg yolk solid content, and most of the constituent components are the odorless phytosterol, further, the egg yolk content is small, the egg yolk has a mild taste, and it can be used in a large amount as a raw material in various foods, and therefore, the original texture and taste of the food are hardly impaired even when it is added in a large amount as compared with the complex, (v) and furthermore, since the proportion of the egg yolk solid content in the complex can be reduced, the protein contained in the egg yolk does not aggregate, and the complex can maintain good dispersibility in an aqueous medium after heat sterilization, (vi) and therefore, the complex is particularly useful for incorporating phytosterol into foods.

That is, the present invention provides a complex of phytosterol and yolk lipoprotein, and particularly provides yolk lipoprotein in the form of a lyso yolk, a cholesterol-removed yolk or a lipoprotein contained in a lyso cholesterol-removed yolk.

Furthermore, the present invention provides food products comprising such complexes. In addition, in the present invention, the food does not include oil-in-water emulsified food.

The present invention also provides a method for producing the complex, which comprises mixing egg yolk lipoprotein and phytosterol in an aqueous medium under stirring, and more specifically, a method for mixing egg yolk liquid and phytosterol under stirring, or mixing egg yolk diluted liquid and phytosterol under stirring.

According to the complex of the present invention in which phytosterol is complexed with egg yolk lipoprotein, the dispersibility of phytosterol in an aqueous medium is greatly improved by a trace amount of egg yolk lipoprotein. In particular, when a processed yolk such as a hemolyzed yolk or a hemolyzed cholesterol-free yolk is used as the yolk lipoprotein, the effect is remarkably improved.

Therefore, by using the complex of the present invention, a desired amount of phytosterol can be added without impairing the taste of the food, even in aqueous foods or emulsified foods. Further, the food containing the complex does not give a rough feeling derived from phytosterol, and gives a smooth texture.

Furthermore, when processed egg yolk such as cholesterol-free egg yolk and lyso-cholesterol-free egg yolk is used as the egg yolk lipoprotein, the complex of the present invention is more suitable for the purpose of intake of phytosterol, i.e., lowering the total cholesterol concentration in blood and the low density lipoprotein-cholesterol concentration, because cholesterol contained in the egg yolk lipoprotein is removed.

Brief Description of Drawings

FIG. 1 is a flow chart of a method for preparing a complex of phytosterol and egg yolk lipoprotein.

FIG. 2 is a graph showing the relationship between the ratio of plant sterol to egg yolk solid content and the absorbance of supernatant of a complex dispersion liquid in the case where a complex is formed between plant sterol and egg yolk.

FIG. 3 is an electrophoretogram of a filtrate of a composite dispersion obtained by stirring and mixing plant sterol and egg yolk.

FIG. 4 is an electron micrograph of the complex.

Detailed Description

The present invention is described in detail below. In the present invention,% means% by weight unless otherwise specified.

In the present invention, egg yolk refers to various forms of egg yolk such as egg yolk liquid obtained by breaking eggs and separating egg white, dried egg yolk, frozen egg yolk, and heat-sterilized egg yolk. These egg yolks include processed egg yolks subjected to various treatments such as hemolysis, decholenization and decholenization.

The egg yolk liquid is obtained by separating egg from egg white, heat sterilizing egg yolk, thawing frozen egg yolk, dissolving dried egg yolk powder in water to conventional degree, subjecting to hemolysis, decholesylation, etc., and undiluted liquid egg yolk.

The egg yolk diluent is obtained by diluting egg yolk with water, egg white solution, seasoning (such as soy sauce and soup stock).

Egg yolk lipoproteins are complexes composed of proteins, phospholipids having a hydrophilic portion and a hydrophobic portion, and neutral lipids such as triacylglycerols and cholesterol. This complex has a structure in which a hydrophilic portion of a protein and a phospholipid is on the outside and a hydrophobic portion is on the inside, and a neutral lipid is encapsulated. The yolk lipoprotein is the main component of yolk, and accounts for about 80% of the solid content of yolk. The yolk solid content is about 50% of the yolk liquid after egg breaking and separation from egg white (about 45% in the case of industrial egg breaking due to mixing of egg white), and yolk lipoprotein is 36-40 wt% of the yolk liquid.

The yolk lipoprotein contained in the lyso-yolk is a part or all of the phospholipids constituting the yolk lipoprotein, and is hydrolyzed into a lysophospholipid substance. In the complex of the present invention, it is preferable to use the yolk lipoprotein contained in the hemolyzed yolk because it can significantly improve the dispersibility of the phytosterol.

The lyso-yolk is obtained by dissolving raw yolk or dried yolk powder in water to obtain a yolk solution, treating with enzyme, and subjecting to lyso-lysis of phospholipids contained therein. The enzyme used in the enzyme treatment is usually phospholipase A (phospholipase A)₁Phospholipase A₂). The egg yolk is treated with phospholipase A, which acts on phospholipid constituting lipoprotein in egg yolk as main component of egg yolk, so that 1-or 2-position fatty acid residue of the phospholipid is hydrolyzed to obtain lysophospholipid.

Conditions for enzyme treatment, for example, in the case of phospholipase A, the enzyme activity per 1kg of egg yolk is 10²～10⁴U, 45-55 deg.c, pH 6-8 and reaction time of 2-12 hr. In the present invention, the ratio of the hemolysis (weight ratio of lysophosphatidylcholine to the total weight of lysophosphatidylcholine and phosphatidylcholine after enzyme treatment) is preferably 10% or more, more preferably 30% or more, when analyzed by the IATROSCAN method (TLC-FID method). Moreover, more than 90% tends to be bitter.

On the other hand, a cholesterol-removed egg yolk is a processed egg yolk from which cholesterol present in egg yolk is reduced or removed. Furthermore, the cholesterol content in raw egg yolk was about 1.2%. In the complex of the present invention, the use of cholesterol-free egg yolk is preferable because the dispersibility of phytosterol can be improved and the intake of cholesterol can be reduced at the same time as the complex is taken.

In this case, the egg yolk liquid to be subjected to the cholesterol removal treatment is preferably dried in advance, from the viewpoint of efficiently performing the cholesterol removal treatment. In this case, the drying means is not particularly limited, and the water content of the desugared egg yolk is adjusted to about 1 to 6% by a method such as spray drying or freeze drying. By the drying treatment, cholesterol in the egg yolk is also concentrated to a content of about 2-3%.

Furthermore, it is preferable that the egg yolk liquid to be subjected to the cholesterol removal treatment is subjected to a desugarization treatment in advance, because the resulting dried cholesterol-removed egg yolk is less likely to brown and can maintain a fresh color. In the desugaring treatment, there are methods using bacteria, yeast, enzyme, etc., and for example, in the case of using yeast, about 0.2% of yeast is added to the egg yolk liquid, desugaring is carried out while stirring in a thermostatic chamber at 30 ℃ for 3 hours, fermentation is stopped after 60 ℃ is reached and the temperature is maintained for 3 minutes, and then cooling is carried out to obtain a desugarized egg yolk liquid. The content of free glucose in raw egg yolk liquid is about 0.2%, and the content of free glucose in raw egg yolk liquid can be reduced to about 0.02-0.1% by the desugaring treatment.

Next, in the cholesterol removal treatment using supercritical carbon dioxide, the yolk is treated with carbon dioxide under the conditions of a critical temperature of 31.0 ℃ or higher and a critical pressure of 7.14MPa or higher, particularly with supercritical carbon dioxide under the conditions of a temperature of 35 to 45 ℃ and a pressure of 13 to 50 MPa. The cholesterol removal treatment itself using such supercritical carbon dioxide is preferably carried out by a conventional method. By this method, for example, the cholesterol content in the treated dried egg yolk after cholesterol removal is about 0.1 to 1.0%.

As another method for removing cholesterol from egg yolk, a method of mixing egg yolk with edible oil and separating and removing the edible oil may be used from 1 time to a plurality of times.

In the method for measuring the cholesterol content of the present invention, the "cholesterol determination method a" described in "japanese food standard ingredient list analysis survey" of food ingredient division (released 1 month in 1997) of the resource research society of the scientific and technical institute is used.

The lysogenized cholesterol-removed yolk is obtained by subjecting the lysogenized yolk to a cholesterol-removal treatment with supercritical carbon dioxide or the like. The cholesterol-removing treatment with supercritical carbon dioxide is carried out in the same manner as described above, and the cholesterol content in the processed dried egg yolk after the treatment is preferably about 0.1-1.0%.

On the other hand, phytosterols have a structure similar to that of cholesterol, exist in a few% of the fat-soluble part of plants, have a melting point of about 140 ℃, and are solid at room temperature. The type of phytosterol used in the present invention is not particularly limited, and examples thereof include β -sitosterol, stigmasterol, campesterol, brassicasterol, and the like. Furthermore, a saturated phytostanol having phytosterols, or a hydrogenated saturated phytostanol other than a natural product may be used.

In the present invention, the phytosterol contains a so-called free body as a main component, but may contain a small amount of esters or the like.

The phytosterol used in the present invention may be in the form of commercially available flakes or powder, preferably powder having an average particle size of less than 50 μm, and particularly preferably less than 10 μm. When a sheet-like or powdery phytosterol having an average particle size of more than 50 μm is used, it is preferable to mix the phytosterol with egg yolk under stirring while reducing the average particle size by using a homogenizer (T.K. MYCOLLOIDER, manufactured by speciality industries, Ltd.). This facilitates the formation of a complex of phytosterol and egg yolk lipoprotein, which has improved dispersibility and is slippery in the mouth.

The mean particle size of the plant sterol was measured by mixing plant sterol with clear water at 20 ℃ and measuring the mixture in a laser diffraction particle size distribution measuring apparatus (SALD-200V ER, manufactured by Shimadzu corporation) and converting the volume of the mixture.

The complex of phytosterol and yolk lipoprotein of the present invention is obtained by mixing the above phytosterol and yolk lipoprotein, preferably in an aqueous medium under stirring. In this complex, it is assumed that the hydrophobic portion of egg yolk lipoprotein having amphiphilicity is attached to the surface of hydrophobic plant sterol, and the plant sterol is covered with the hydrophilic portion directed outward (water side), whereby the surface of the complex is hydrophilized, water dispersion is possible, mutual aggregation is not caused, stable dispersion is achieved in the water phase, and mutual aggregation is not caused, and therefore, it is difficult to generate a rough feeling even when added to a food.

In addition, conventionally, phospholipids have been used to obtain emulsions of phytosterols (see patent documents 2 and 3), and egg yolk contains phospholipids (egg yolk phospholipids). However, since the phospholipids in egg yolk exist as egg yolk lipoproteins that bind to proteins, the phospholipids that form complexes in egg yolk are completely different from the phospholipids described in patent documents 2 and 3 in their action on phytosterols. That is, a complex can be formed only by stirring and mixing egg yolk lipoprotein and phytosterol in an aqueous medium, whereas phospholipid alone does not form a complex as in egg yolk lipoprotein (see reference example 2).

In the present invention, the phytosterol is mixed with the yolk lipoprotein under stirring, and as the yolk lipoprotein, a yolk diluent in which the yolk is appropriately diluted in an aqueous medium is preferably used. In this case, the egg yolk liquid that has been beaten and separated from egg white is mixed with phytosterol under stirring, and the resultant mixture is not necessarily diluted in an aqueous medium, but the dried egg yolk is diluted in an aqueous medium and used. This is preferable because the phytosterol and the yolk lipoprotein are easily stirred and a complex of the phytosterol and the yolk lipoprotein is easily formed. Here, if the ratio of the aqueous medium is too small, the ratio of the phytosterol is relatively high, and the viscosity of the egg yolk diluted liquid increases, so that long-time stirring is required, whereas if the ratio of the aqueous medium is too high, the ratio of egg yolk lipoprotein occupied in the complex is excessively reduced, and the dispersibility of the complex in the aqueous medium is lowered, which is not preferable.

The aqueous medium used for the preparation of the diluted egg yolk liquid is preferably a medium having a water content of 90 wt% or more, and for example, a protein liquid, a seasoning (e.g., soy sauce, broth), or the like can be used in addition to clear water. Further, although a small amount of an oil or fat such as salad oil and an organic solvent such as alcohol may be added to the aqueous medium, the addition of a large amount of an oil or fat such as salad oil is not preferable because the affinity between the phytosterol and the oil or fat is high, and the binding between the phytosterol and the yolk lipoprotein is impaired, and the yolk lipoprotein may be denatured by the addition of a large amount of an organic solvent such as alcohol.

When egg yolk and phytosterol are stirred and mixed in an aqueous medium to form a complex of phytosterol and egg yolk lipoprotein, the dispersibility of the complex in the aqueous medium can be improved even if the amount of egg yolk used is extremely small relative to the amount of phytosterol used. For example, in order to disperse 100 parts by weight of the phytosterol in water, it is sufficient that the egg yolk solid content is 0.54 parts by weight or more, in other words, the amount of the phytosterol may be 185 parts by weight or less relative to 1 part by weight of the egg yolk solid content.

Further, the ratio of the egg yolk to the plant sterol in the formation of the complex is such that the higher the ratio of the plant sterol to 1 part by weight of the egg yolk solid content is, the more the influence of the egg yolk in the complex on the taste and texture of the food can be reduced when the complex is added to the food. Therefore, in the case where it is necessary to suppress the influence of the taste of egg yolk depending on the kind of food, it is not preferable to add an excessive amount of egg yolk to the plant sterol, and from this point of view, it is preferable to mix the plant sterol in an amount of 4 parts by weight or more to 1 part by weight of the egg yolk solid content.

As described above, the ratio of the egg yolk to the plant sterol in the formation of the complex is preferably 4 to 185 parts by weight based on 1 part by weight of the egg yolk solid content. The yolk solid component contains yolk lipoprotein about 8 parts, and the plant sterol and yolk are mixed under stirring according to the above ratio to obtain a complex of 1 part by weight of yolk lipoprotein and 5-232 parts by weight of plant sterol.

A typical method for producing a complex of phytosterol and egg yolk lipoprotein is as follows. First, the eggs are opened and the egg white is removed, and the yolk is taken out as yolk liquid.

Then, the egg yolk liquid is mixed with an aqueous medium such as clear water under stirring to dilute the egg yolk liquid. Although a complex of phytosterol and yolk lipoprotein can be produced without diluting the yolk liquid, when the amount of water is small, the viscosity becomes high as the amount of phytosterol added increases, the stirring force needs to be large, and the required time is long, so that when it is necessary to increase the ratio of phytosterol to 1 part by weight of yolk lipoprotein, it is preferable to dilute the yolk liquid with an aqueous medium such as clear water to prepare a yolk diluted liquid.

Then, the egg yolk diluent and the plant sterol were thoroughly and uniformly mixed and stirred (for example, 10000rpm, 5 to 20 minutes) using a homogenizer such as a high-speed mixer, a colloid mill, a high-pressure homogenizer, and a t.k.myocolor (manufactured by special machine industries) to produce a complex of the plant sterol and egg yolk lipoprotein. The temperature during stirring and mixing can be controlled at normal temperature (20 ℃), and the temperature is preferably 45-55 ℃.

The resulting composite may be used in food in the form of a dispersion, but may be a dried powder such as freeze-dried or spray-dried for long-term storage.

Specific examples of the food which may contain the complex include processed egg products such as scrambled eggs, butter scrambled eggs, soft omelettes, and steamed custards, minced meat products such as fish cakes and fish rolls, processed meat products such as hamburgers and sausages, noodles, beverages such as milk and lactic acid bacteria beverages, seasonings such as sauces and mayonnaises, and desserts such as ice creams, cakes and cookies.

Further, the preferable amount of the complex to be added to the food should be about 0.5 to 10% by weight in the case of milk or scrambled eggs, for example, considering that the cholesterol concentration in blood is lowered when the amount of phytosterol taken for 1 day is 1g or more, depending on the food.

In addition, even in foods, in the case of fried eggs, steamed egg custards, mayonnaise, and the like, in which the amount of egg yolk as a raw material is large, a complex can be formed by directly adding phytosterol to egg yolk as a raw material in advance, and in the case of foods in which egg yolk is not used as a raw material, such as milk beverages and coffee, a complex prepared by reducing the proportion of egg yolk as much as possible may be added.

Examples

The present invention is described in detail below based on examples.

Example 1: constituent Components of analysis Complex

(1) According to the flow chart of fig. 1, complexes of phytosterols and egg yolk lipoproteins were prepared from phytosterols and egg yolk as follows.

First, 95g of clear water was added to 5g of egg yolk liquid (egg yolk solid content: 2.5g, egg yolk lipoprotein in egg yolk solid content: about 2g), and the mixture was stirred at 2000rpm for 1 minute in a stirrer (HISCOTRON, manufactured by hitachi scientific instruments) to prepare an egg yolk diluted solution. Then, 2.5g of phytosterol (free form 97.8%, ester 2.2%, average particle diameter of about 3 μm) was added thereto while stirring at 5000rpm, and further stirred at 10000rpm for 5 minutes to obtain a composite dispersion liquid composed of phytosterol and egg yolk lipoprotein.

1g of the obtained dispersion was taken out, 4g of 0.9% brine was added thereto, the mixture was degassed under a vacuum of 10mmHg for 1 minute in a vacuum drier (VOS-450D, manufactured by Tokyo Raiko instruments Co., Ltd.), and the precipitate was separated from the supernatant by centrifugation at 3000rpm for 15 minutes in a centrifugal separator (H-108 ND type, manufactured by Kogyo Seisaku-Sho Co., Ltd.). The supernatant was filtered through a 0.45 μm filter and then through a 0.2 μm filter to remove the complex and phytosterols that did not form the complex.

The amount of protein in the filtrate was measured by measuring the absorbance (o.d.) of the filtrate at 280nm (absorption of amino acids having aromatic rings in the protein) using a spectrophotometer (manufactured by hitachi, U-2010) with 0.9% saline as a control.

The amounts of phytosterols added were varied as shown in Table 1, and the absorbances were measured in the same manner (examples 1-2 to 1-8). The results are shown in Table 1 and FIG. 2.

TABLE 1

	Amount of phytosterol added (g)	Phytosterol/egg yolk solid content (weight ratio)	Phytosterol/egg yolk lipoprotein (weight ratio)	Absorbance of the filtrate (280nm)
					Examples 1 to 1	2.5	1	1.3	2.770
Examples 1 to 2	5.0	2	2.5	1.842
					Examples 1 to 3	7.5	3	3.8	1.002
Examples 1 to 4	10.0	4	5.0	0.626
					Examples 1 to 5	12.5	5	6.3	0.590
Examples 1 to 6	15.0	6	7.5	0.548
					Examples 1 to 7	17.5	7	8.8	0.577
Examples 1 to 8	20.0	8	10.0	0.536

As can be seen from table 1 and fig. 2, when the amount of phytosterol is 4g or less based on 1g of egg yolk solid content, the ratio of phytosterol to egg yolk solid content increases and the absorbance of the filtrate decreases. Therefore, by adding phytosterol to the egg yolk diluent, the protein contained in the egg yolk is combined with the phytosterol, and the protein concentration in the filtrate is reduced. On the other hand, when the egg yolk solid content of 1g of the egg yolk solid content was 4g or more, the absorbance of the filtrate was approximately constant, and thus it was found that there was protein not bound to the phytosterol in the filtrate.

In addition, when the amount of phytosterol is 4g or less based on 1g of egg yolk solid content, proteins bonded to phytosterol are present in the filtrate, and 1g of egg yolk solid content is not remained for forming a complex, and it is found that 4g or more of phytosterol is required (5 g or more of phytosterol based on 1g of egg yolk lipoprotein).

(2) The protein present in the filtrate of example 1-1 and the filtrate of example 1-6 obtained in (1) was measured not only for absorbance at 280nm as described above but also for absorbance at 440nm, and the ratio of the absorbance at 440nm to the absorbance at 280nm was determined. Here, 440nm is the absorption wavelength of the oil-soluble pigment (carotene) contained in the lipoprotein. The results are shown in Table 2.

TABLE 2

As is clear from Table 2, in examples 1 to 6, since the absorbance at 440nm was extremely low in the case where a proper amount of egg yolk was combined with phytosterol, almost no egg yolk lipoprotein remained in the filtrate. Thus, a complex is formed between the egg yolk lipoprotein and the phytosterol.

Further, as can be seen from example 1-1, the amount of egg yolk having phytosterol was excessive, the absorbance at 280nm and 440nm was high, and the ratio of the absorbance at 440nm to the absorbance at 280nm was larger than that in example 1-6, so that both egg yolk lipoproteins capable of forming complexes and proteins incapable of forming complexes were present in the filtrate, and further, the remaining egg yolk lipoproteins were more than that in example 1-6.

(3) The filtrates from example 1-1 and examples 1-6 in (1) were subjected to SDS polyacrylamide gel electrophoresis to examine the amounts of proteins that can form complexes with phytosterols and proteins that do not form complexes with phytosterols.

In this case, as the measurement condition of electrophoresis, a part of the filtrate was freeze-dried and dissolved in a sample buffer, a fixed amount thereof was put on a gel having a concentration gradient of 4 to 20%, and electrophoresis was carried out at a constant current of 20mA, and the protein was stained with Coomassie blue. (composition of sample buffer: 5.0mL of distilled water, 1.25mL of 0.5M Tris-HCl buffer, 1.0mL of glycerol, 2.0mL of 10% SDS, 0.5mL of 2-mercaptoethanol, and 0.05% bromophenol blue), the electropherogram is shown in FIG. 3.

As a result, in the electropherogram of example 1-1 in which the ratio of egg yolk to phytosterol was excessive, both the protein specific to the water-soluble fraction (molecular weight 36.5 × 1000 in fig. 3) and the protein specific to the egg yolk lipoprotein (molecular weight 200 × 1000 in fig. 3) were detected, whereas in the case of example 1-6 in which the ratio of egg yolk to phytosterol was not excessive, the protein specific to the egg yolk lipoprotein was not detected, and only the protein specific to the water-soluble fraction was detected. It is seen that in egg yolk, the protein not forming the complex is a protein specific to the water-soluble portion, and the protein forming the complex is egg yolk lipoprotein.

(4) In examples 1 to 4, the precipitate left after the separation of the supernatant was washed with physiological saline about 60 times the weight of the precipitate, centrifuged again to obtain a precipitate, freeze-dried to obtain a composite powder, the powder was dispersed on a conductive tape, carbon deposition was performed to maintain conductivity, and a photograph was taken with an electron emission scanning electron microscope (JSM-7400F, manufactured by japan electronics, inc.) at an acceleration voltage of 5kv and a magnification of 10 ten thousand. This photograph is shown in fig. 4. From the photograph, it is understood that the surface of phytosterol is covered with lipoprotein (LDL).

Example 2A: study on the ratio of phytosterol to yolk lipoprotein in the preparation of the Complex

The egg yolk liquid (solid content: 45%) obtained by industrially beating eggs, the amount of clear water and the amount of phytosterol were varied as shown in table 3A to prepare a dispersion of a complex of phytosterol and egg yolk lipoprotein, and from the dispersibility and the stirring property of the dispersion, the water content and the ratio of phytosterol to egg yolk required for preparing the complex of phytosterol and egg yolk lipoprotein were investigated.

In this case, clear water was added to an egg yolk solution (solid content: 45%) obtained by beating an egg, and the egg yolk solution was stirred at 2000rpm for 1 minute with a stirrer (HISCOTRON, manufactured by japan medical devices corporation), and after the egg yolk solution was blended with clear water, the temperature was raised to 45 ℃.

Further, as for the dispersibility of the dispersion, 0.5g of a dispersion of a complex of phytosterol and yolk lipoprotein was diluted with 10mL of 0.9% saline in a test tube (inner diameter: 1.6cm, height: 17.5cm), shaken by stirring with a test tube mixer (IWAKI GLASS MODEL-TM-151 type) for 10 seconds, allowed to stand at room temperature for 1 hour, placed in a vacuum drier (manufactured by Tokyo chemical Co., Ltd., VOS-450D), degassed at room temperature (20 ℃) under a vacuum degree of 10mmHg or less, and when no supernatant was observed after degassing, O was defined as a visible supernatant, and x was defined as a visible supernatant. The specific gravity of the phytosterol was determined by heating and dissolving the phytosterol, cooling the phytosterol, and immersing the phytosterol in ethanol solutions of different specific gravities to settle and float, and the specific gravity was 0.98, so that the supernatant in the dispersibility test was considered to be the phytosterol.

Table 3A shows the results thereof.

TABLE 3A

As is clear from Table 3A, in order to impart good dispersibility to the complex, 185g or less of phytosterol (about 232g of phytosterol per 1g of yolk lipoprotein) was used per 1g of yolk solid content (examples 2A to 13), in other words, the yolk solid content was only used in such a minute amount that 0.54 parts by weight or more (0.43 parts by weight or more of yolk lipoprotein) was used per 100 parts by weight of phytosterol dispersed in water.

In examples 2A-1 and 2A-2 shown in Table 3A, the viscosity increased slightly when the phytosterol was added, and stirring and mixing were required for 10 minutes or more, but in examples 2A-3 to 2A-13, stirring and mixing could be easily performed for a short time (about 5 minutes). Therefore, the moisture content in the dispersion liquid is preferably 48.9% or more.

Example 2B: investigation of the ratio of phytosterol to lysozyed egg yolk liquid when preparing the Complex

Adding into egg yolk liquid (solid content 45%) obtained by industrially beating eggAdding salt to obtain salted egg yolk solution with salt concentration of 10 wt%, and adding phospholipase A₂The resultant was subjected to enzyme treatment to obtain a hemolyzed salted egg yolk solution having a hemolysis rate of 50%.

Then, a dispersion of a complex of phytosterol and egg yolk lipoprotein was prepared by changing the amounts of the hemolyzed egg yolk liquid, the amount of fresh water and the amount of phytosterol in accordance with table 3B in the same manner as in example 2A, and from the dispersibility of the dispersion, the ratio of phytosterol to the hemolyzed egg yolk liquid required for preparing a complex of phytosterol and egg yolk lipoprotein was examined in the same manner as in example 2A. The results are shown in Table 3B.

TABLE 3B

As is clear from table 3B, in order to impart good dispersibility to the complex, 247g or less of phytosterol (which is about 1.3 times as much as the untreated egg yolk in example 2A) was used per 1g of egg yolk solid content (see examples 2B-7), in other words, in order to disperse 100 parts by weight of phytosterol in water, the egg yolk solid content was only used in such a minute amount as 0.40 parts by weight or more.

It is presumed that the higher dispersibility of phytosterol in a hemolyzed egg yolk liquid in water is about 1.3 times that of untreated egg yolk because the phospholipid contained in the enzyme-treated egg yolk lipoprotein in the hemolyzed egg yolk liquid is lysolyzed to improve the hydrophilicity, and thus the hydrophilicity of the complex of egg yolk lipoprotein and phytosterol is improved, and the dispersibility in water is also improved.

Example 2C: study on the ratio of phytosterol to cholesterol-removed egg yolk in the preparation of the Complex

Egg yolk liquid (solid content 45%) obtained by industrially beating egg is desugarized with yeast, dried, and subjected to supercritical carbon dioxide to remove cholesterol to obtain dried egg yolk with cholesterol content of 0.25% and solid content of 95% (determined by drying at 105 deg.C).

The amounts of the cholesterol-removed dried egg yolk, fresh water and phytosterol were varied as shown in Table 3C to prepare a dispersion of a complex of phytosterol and egg yolk lipoprotein, and the ratio of phytosterol to cholesterol-removed egg yolk required for preparing the complex of phytosterol and egg yolk lipoprotein was investigated from the dispersibility of the dispersion.

In this case, clear water was added to the cholesterol-removed dried egg yolk, and the resulting mixture was stirred with a stirrer (HISCOTRON) at 5000rpm for 2 minutes to blend the cholesterol-removed egg yolk liquid with the clear water, then heated to 45 ℃, then phytosterol (same as in example 1) was slowly added thereto while stirring at 8000rpm, and after the completion of the addition, the mixture was further stirred at 10000rpm to obtain a composite dispersion of phytosterol and egg yolk lipoprotein.

Then, dispersibility was evaluated in the same manner as in example 2A. The results are shown in Table 3C.

TABLE 3C

As is clear from table 3C, in order to impart good dispersibility to the complex, it is sufficient to use not more than 211g of phytosterol (about 1.1 times as much as the untreated egg yolk of example 2A) per 1g of the dried cholesterol-removed egg yolk (in terms of solid content) (see examples 2C-6), in other words, to disperse 100 parts by weight of phytosterol in water, the amount of the dried cholesterol-removed egg yolk used is as small as not less than 0.47 parts by weight (in terms of solid content).

It is presumed that the ability of dispersing phytosterol in the cholesterol-removed dried egg yolk in water is about 1.1 times higher than that in untreated egg yolk because cholesterol and neutral lipids that do not contribute to the formation of a complex with phytosterol are removed from the egg yolk lipoproteins by the cholesterol-removal treatment of the cholesterol-removed dried egg yolk, and the concentrations of proteins and phospholipids that contribute to the formation of a complex with phytosterol are relatively high.

Example 2D: investigation of the ratio of phytosterol to lysolyzed Cholesterol-removed egg yolk in preparation of Complex

Egg yolk liquid (solid content 45%) obtained by industrially beating egg is treated with phospholipase A₂The resultant was subjected to enzyme treatment to obtain a hemolyzed salted egg yolk solution having a hemolysis rate of 55%. Then drying the egg yolk liquid, and removing cholesterol by supercritical carbon dioxide to obtain lyso cholesterol-removed dried egg yolk with cholesterol content of 0.15% and solid content of 96% (determined by drying at 105 deg.C).

The amounts of the lysogenized dried egg yolk, the fresh water and the phytosterol were varied as shown in table 3D, a composite dispersion of the phytosterol and the egg yolk lipoprotein was prepared in the same manner as in example 2C, and from the dispersibility of the dispersion, the ratio of the phytosterol to the lysogenized cholesterol-removed egg yolk required for preparing the composite of the phytosterol and the egg yolk lipoprotein was examined in the same manner as in example 2A. The results are shown in Table 3D.

TABLE 3D

As is clear from table 3D, in order to impart good dispersibility to the complex, plant sterol (about 1.7 times as much as the untreated egg yolk of example 2A) of 313g or less (see example 2D-7) was used for 1g of the lyso-cholesterically removed dried egg yolk (in solid content conversion) (in other words, in order to disperse 100 parts by weight of plant sterol in water, the amount of the cholesterically removed dried egg yolk used was as small as 0.32 parts by weight or more (in solid content conversion).

It is thus presumed that the higher ability of the lysogenized dried egg yolk to disperse phytosterols in water is about 1.7 times higher than that of untreated egg yolk because the increased hydrophilicity of the egg yolk lipoproteins caused by the above-mentioned lysogenization treatment has a synergistic effect with the concentration of the proteins and phospholipids contributing to the formation of complexes in the egg yolk lipoproteins caused by the cholesterol-removing treatment.

Example 3: fried egg added with phytosterol

An egg was subjected to industrial egg beating to remove an egg yolk liquid (solid content 45%), and the egg yolk liquid was put into a mixer (HISCOTRON, manufactured by Nihon scientific instruments Co., Ltd.) to which 5% (0.15 g of phytosterol to 1g of egg yolk lipoprotein), 10% (0.31 g of phytosterol to 1g of egg yolk lipoprotein) or 20% (0.69 g of phytosterol to 1g of egg yolk lipoprotein) of phytosterol (the same as in example 1) was gradually added while stirring at 5000rpm, followed by stirring at 10000rpm for 5 minutes to prepare a composite dispersion of phytosterol and egg yolk lipoprotein for 3 phytosterol concentrations (examples 3-1 to 3-3). Further, according to example 1(1), since egg yolk lipoproteins remain in the dispersion when 1g of egg yolk lipoproteins are not more than 5g of phytosterols, the egg yolk lipoproteins are present in excess in examples 3-1 to 3-3.

The resulting composite dispersion was used to prepare a scrambled egg slurry in accordance with the ratio in table 4, and the scrambled eggs were scrambled to give thick eggs and tasted.

Further, as a control, the same procedure as in example 3 was repeated except that phytosterol was not mixed, and the resulting egg was fried to a thick layer and tasted.

The results are shown in Table 5.

TABLE 4

Proportion (g) of fried egg pulp

Composite dispersion	18
		Protein liquid	62
Adding white sugar	7
		Cooking wine	0.5
Soy sauce	0.5
		Clean water	12
(Total)	(100)

TABLE 5

	Amount of phytosterol to be added to the dispersion (%)	Phytosterol/egg in dispersionYellow lipoprotein (parts by weight)	Concentration of phytosterol in Stir-fried egg pulp (%)	Taste of scrambled eggs	Egg taste of scrambled eggs
						Control	0	0	0	With biting, slippery and good	Is provided with
Example 3-1	5	0.15	0.9	Same as above	Is provided with
						Examples 3 to 2	10	0.31	1.8	Same as above	Is provided with
Examples 3 to 3	20	0.69	3.6	Same as above	Is provided with

As is clear from table 5, in this example, although the plant sterol was added to the scrambled egg, since the plant sterol and the egg yolk lipoprotein formed a complex, the scrambled egg was not coarse with the plant sterol, the egg taste was good, the mouth feel was good, and the scrambled egg to which the plant sterol was added could be scrambled, as in the control to which the plant sterol was not added.

Example 4: beverage containing phytosterol

(1) Preparation of the composite

The eggs were beaten and 18g of yolk liquid (yolk solid content: 50%, yolk lipoprotein content in the yolk liquid: about 7.2g) was taken out, 9982g of clear water was added, and the mixture was stirred at 5000rpm for 3 minutes by a stirrer (TK high speed mixer, manufactured by speciality industries, Ltd.) to homogenize the mixture, and then 1500g of phytosterol (same as in example 1) (208 parts by weight of phytosterol per 1 part by weight of yolk lipoprotein) was slowly added while stirring at 12000rpm, and further stirring was continued for 5 minutes. Then, the mixture was heated at 61 ℃ for 4 minutes by a propeller mixer for a ship to sterilize at low temperature, thereby preparing a composite dispersion of phytosterol and egg yolk lipoprotein.

Part of the obtained dispersion was freeze-dried, pulverized in a mortar, and sieved through a 30-mesh sieve to obtain a powder containing a complex of phytosterol and egg yolk lipoprotein (complex content: 99.88%).

(2) Beverage containing composite dispersion

To 17g of each of commercially available milk (pH6.72) and commercially available lactic acid bacteria beverage (pH3.67), 3.07g (0.4 g in terms of phytosterol) of the dispersion of phytosterol and yolk lipoprotein prepared in (1) was added, and the mixture was stirred at 10000rpm for 2 minutes by a stirrer (HISCOTRON, manufactured by Nihon-Denko Co., Ltd.) to prepare a beverage containing the phytosterol. The test tube (inner diameter: 1.6cm, height: 17.5cm) was filled with the dispersion medium, and the mixture was allowed to stand at 5 ℃ for 3 hours, 20 hours or 2 days, and the dispersion state of each was observed to determine the height of the supernatant formed in the test tube.

As a control, 0.4g of phytosterol (same as in example 1) was dispersed directly in each beverage in place of the complex of phytosterol and egg yolk lipoprotein.

The results are shown in Table 6.

TABLE 6

As can be seen from table 6, the lactic acid bacteria beverage and milk to which the composite dispersion liquid was added did not show an upward floating substance and were uniformly dispersed when each was stored at 5 ℃ for 2 days or 20 hours, and when phytosterol was directly added to the beverage without being converted into a composite, the phytosterol floated within 3 hours, and it was considered that the dispersion was unstable.

Example 5: redispersion of composite powder

0.9% saline was added to test tubes (inner diameter: 16mm, height: 17.5cm) each containing 0.202g, 0.405g, and 1.52g of the powder of a complex containing phytosterol and egg yolk lipoprotein obtained in example 4(1) until 10g of the powder was obtained, the powder was subjected to ultrasonic irradiation with an ultrasonic wave washer (model name: Sine Sonic100, manufactured by International Electrical ERTEC corporation) for 1 minute, and the dispersion state and the presence or absence of an upper layer of the complex were observed after standing at room temperature for 1 hour.

As a control, 0.2g, 0.4g, and 1.5g of phytosterol (same as in example 1) was directly dispersed in saline instead of the powder containing the complex, and the dispersion state and the presence or absence of the supernatant layer were observed. The results are shown in Table 7.

TABLE 7

As shown in Table 7, the phytosterols in the control were not dispersed at all, and no matter what amount of addition, the supernatant was visible, and the subbing liquid was transparent. On the other hand, when the composite powder of example 5 was redispersed, the whole dispersion was cloudy and some precipitates were observed regardless of the amount added.

Reference example 1: mayonnaise-like emulsified food

Complexes of phytosterols and egg yolk lipoproteins were prepared as follows according to the formulation of table 8. First, clear water was added to egg yolk liquid (manufactured by yobi corporation, salted egg yolk (10% salt, 40.5% egg yolk solid content)) and the mixture was stirred at 5000rpm for 3 minutes in a mixer (TK high speed mixer, manufactured by speciality industries) to mix the clear water with the egg yolk. Then, while stirring was continued at a stirring speed of 14000rpm, phytosterol (the same as in example 1) was slowly added thereto and stirred for 20 minutes to obtain a composite dispersion of phytosterol and egg yolk lipoprotein.

Using the obtained composite dispersion liquid, mayonnaise-like emulsified foods were prepared in the following proportions according to table 9. Firstly, adding a composite dispersion liquid of phytosterol and yolk lipoprotein into a household stirrer, adding protein liquid and clear water, stirring for 1 minute, then adding table salt, processed starch, chilli powder, xanthan gum, white sugar and sodium glutamate, stirring for 1 minute, slowly adding rapeseed oil, stirring for 3 minutes, slowly adding table vinegar, stirring for 1 minute under the vacuum degree of 0-10mmHg, degassing, and preparing the yolk sauce-like emulsified food.

As a control, in the formulation shown in table 10, the plant sterol was dispersed in rapeseed oil in advance, and then the mayonnaise-like emulsified food was prepared. That is, the phytosterol was added to rapeseed oil, and the mixture was stirred in a mixer (TK high speed mixer, manufactured by Special mechanical Co., Ltd.) at 10000rpm for 10 minutes to prepare a phytosterol dispersed oil. Then, egg yolk (manufactured by churian corporation, salted egg yolk (salted 10%)), egg white liquid and clear water were added to a home mixer and stirred for 1 minute, salt, processed starch, chili powder, xanthan gum, white sugar, and sodium glutamate were added and stirred for 1 minute, phytosterol dispersed oil was slowly added and stirred for 3 minutes, vinegar was slowly added and stirred for 1 minute, and stirring was carried out under a vacuum of 0 to 10mmHg for 1 minute to degas, thereby preparing an egg yolk sauce-like emulsified food.

The mayonnaise-like foods of reference example 1 and the control were tasted and the mouthfeel was measured. Further, each mayonnaise-like emulsified food was filled in a flexible bottle made of 200g of filling polyethylene by 120g, and the separation test was repeated 10 times by pressing the center of the flexible bottle with a hand without capping, and the emulsified state of the mayonnaise-like emulsified food immediately after the separation test and stored for 1 day after the separation test was observed. The results are shown in Table 11.

TABLE 8

Ratio (parts by weight) of phytosterol to yolk lipoprotein complex dispersion liquid

Yolk liquid (10% salted) (yolk lipoprotein)	11.04(3.6)
		Plant sterol	6.33
Clean water	12.63
		(Total)	(30.00)

TABLE 9

Formulation of mayonnaise-like emulsified food in referential example 1 (%)

Rapeseed oil	28
		Composite dispersion liquid of phytosterol and yolk lipoprotein	30
Protein liquid	3
		Vinegar	7
Salt	1.3
		Processing starch	3.5
Chili powder	0.2
		Xanthan gum	0.5
Adding white sugar	0.5
		Glutamic acid sodium salt	0.5
Clean water	25.5
		(Total)	(100.0)

Watch 10

Formulation of control mayonnaise-like emulsified food (%)

Rapeseed oil	28.0
		Yolk liquid (10% with salt)	11.04
Plant sterol	6.33
		Protein liquid	3.0
Vinegar	7.0
		Salt	1.3
Processing starch	3.5

Chili powder	0.2
		Xanthan gum	0.5
Adding white sugar	0.5
		Glutamic acid sodium salt	0.5
Clean water	38.13
		(Total)	(100.00)

TABLE 11

	Taste of the product	Immediately after the separation test	Storage for 1 day after separation test
				Reference example 1	Skating	Is not separated	Is not separated
Control	Is not smooth	Cracks appear, whereby oil is penetrated	Increased oil bleed compared to immediately after the separation test

As can be seen from the results in table 11, in the control in which the phytosterol was dispersed in the rapeseed oil in advance, the mouthfeel was not smooth, and cracks, oil bleeding, and the like occurred immediately after the separation test, so that a stable mayonnaise-like emulsified food could not be obtained.

On the contrary, the mayonnaise-like emulsified food of reference example 1 had a smooth texture and was free from oil bleeding and a stable emulsified state because the plant sterol and the egg yolk were mixed in advance to form a complex.

Reference example 2: in mayonnaise-like emulsified food, the difference in emulsion stability of a composite dispersion of phytosterol and yolk lipoprotein and a dispersion of phytosterol and phospholipid was compared

Mayonnaise-like emulsified food products using a composite dispersion of phytosterol and egg yolk lipoprotein and mayonnaise-like emulsified food products using a dispersion of phytosterol and phospholipid were prepared separately as follows, and their emulsion stability was compared.

(1) Preparation method of mayonnaise-like emulsified food

First, a composite dispersion of phytosterol and egg yolk lipoprotein was prepared in the same manner as in reference example 1, according to the formulation of table 12. In this case, the yolk is a yolk liquid (solid content 45%) obtained after beating eggs with eggs.

TABLE 12

Ratio (parts by weight) of phytosterol to yolk lipoprotein complex dispersion liquid

Yolk liquid (yolk lipoprotein)	2.2(0.8)
		Plant sterol	6.0
Clean water	15.8
		(Total)	(24.0)

On the other hand, as a control, a dispersion of phytosterol and phospholipid was prepared as follows according to the formulation in table 13. That is, first, after the egg yolk liquid (yolk solid content: 45%) obtained by beating the eggs is spray-dried to prepare dried egg yolk, lipids are extracted in ethanol, the ethanol is removed, and neutral lipids are removed by acetone to obtain phospholipids (powder).

Clean water was added to the phospholipid, and the mixture was stirred at 5000rpm for 2 minutes by a stirrer (HISCOTRON, manufactured by hitachi medical science corporation), after which the clean water was blended with the phospholipid, the mixture was heated to 45 ℃, and the phytosterol (same as in example 1) was slowly added while stirring at 5000rpm, and after the completion of the addition, the mixture was further stirred at 10000rpm for 5 minutes to prepare a dispersion of the phytosterol and the phospholipid.

Watch 13

Ratio of Complex of phytosterol and phospholipid (parts by weight)

Phospholipid (powder)	1.2
		Plant sterol	6.0
Clean water	16.8
		(Total)	24.0)

Using each of the obtained dispersions, mayonnaise-like emulsified foods were prepared according to the compounding ratios shown in tables 14 and 15. This preparation method was the same as in reference example 1 except that the egg yolk liquid (solid content: 45%) was first stirred together with the dispersion liquid, the protein liquid and clear water in a home mixer.

TABLE 14

Formulation of mayonnaise-like emulsified food in referential example 2 (%)

Rapeseed oil	28.0
		Composite dispersion liquid of phytosterol and yolk lipoprotein	24.0
Egg yolk liquid	8.0

Protein liquid	3.0
		Vinegar	7.0

Salt	1.3
		Processing starch	3.5
Chili powder	0.2

Xanthan gum	0.5
		Adding white sugar	0.5
Glutamic acid sodium salt	0.5
		Clean water	23.5
(Total)	(100.0)

Watch 15

Formulation of control mayonnaise-like emulsified food (%)

Rapeseed oil	28.0
		Dispersion of phytosterols and phospholipids	24.0
Egg yolk liquid	8.0
		Protein liquid	3.0
Vinegar	7.0
		Salt	1.3
Processing starch	3.5
		Chili powder	0.2
Xanthan gum	0.5
		Adding white sugar	0.5
Glutamic acid sodium salt	0.5
		Clean water	23.5
(Total)	(100.0)

(2) Comparison of emulsion stability

The emulsion stability of mayonnaise-like emulsified food using a composite dispersion of phytosterol and egg yolk lipoprotein and mayonnaise-like emulsified food using a dispersion of phytosterol and phospholipid was investigated as follows.

200g of each mayonnaise-like emulsified food was filled in a flexible bottle made of 200g of filling polyethylene, and the resulting product was stored at 30 ℃ for 1 day with a lid and at 30 ℃ for 3 months with a lid, respectively, and subjected to a separation test (emulsion stability test).

The separation test was conducted by opening the cap, taking out 80g of the content, opening the cap, pressing the center of the flexible bottle with hand, separating, and repeating this 10 times, and observing the emulsified state immediately after the repetition. The results are shown in Table 16.

TABLE 16

	After 1 day (30 ℃ C.)	After 3 months
			Composite dispersion liquid of phytosterol and yolk lipoprotein	Stable emulsion state without change	Stable emulsion state without change
Dispersion of phytosterols and phospholipids	Oil bleed out in small amounts	Cracking and oil separation

From the results shown in table 16, it is assumed that mayonnaise-like emulsified food products using a dispersion of phytosterol and phospholipid were prepared as general mayonnaise, and although a sufficient amount of mayonnaise was used (about 3 to 15% of the amount of mayonnaise in commercially available mayonnaise-like emulsified food products), oil leaked in only 1 day, and cracks appeared after 3 months, and further oil separation appeared. The reason for this oil separation is that the oil adheres to the surface of the hydrophobic phytosterol particles because the phytosterol and the phospholipid do not form a complex, thereby promoting the breakdown of the emulsification.

On the contrary, the mayonnaise-like emulsified food using the composite dispersion of phytosterol and egg yolk lipoprotein did not separate after 3 months, and the emulsion stability was good. This is presumably because a complex of phytosterol and egg yolk lipoprotein was formed.

Claims (20)

1. The complex of the phytosterol and the yolk lipoprotein, wherein the composition ratio of the phytosterol to the yolk lipoprotein is as follows: the phytosterol is 5-232 parts by weight relative to 1 part by weight of egg yolk lipoprotein, the egg yolk lipoprotein covers the phytosterol in the complex, and the complex is dispersed in water.

2. The complex as claimed in claim 1, wherein in manufacturing the complex, a flaky or powdery phytosterol is used.

3. The complex as claimed in claim 1, wherein the yolk lipoprotein is a lipoprotein contained in a lyso-yolk, a decholesterolized yolk or a lyso-decholesterolized yolk.

4. The composite body according to any one of claims 1 to 3, which is a dry powder.

5. A food product to which the complex according to any one of claims 1 to 4 is added.

6. An egg-processed product to which the complex according to any one of claims 1 to 4 is added.

7. A beverage to which the complex according to any one of claims 1 to 4 is added.

8. An aqueous emulsion product comprising the complex of any one of claims 1-4.

9. A meat-processing product comprising the complex as defined in any one of claims 1 to 4.

10. Seasoning comprising the complex according to any one of claims 1 to 4.

11. A snack comprising the complex of any of claims 1-4.

12. Noodles comprising the complex according to any one of claims 1 to 4.

13. Ice cream comprising a complex according to any one of claims 1 to 4.

14. A method for producing the composite body according to any one of claims 1 to 4, characterized in that: mixing egg yolk lipoprotein and phytosterol in an aqueous medium under stirring.

15. The method for producing a complex according to claim 14, wherein 232 parts by weight or less of the phytosterol is used based on 1 part by weight of the lipoprotein, except for the case where the phytosterol is 0.

16. The method for producing a complex according to claim 14 or 15, wherein egg yolk liquid is used as the egg yolk lipoprotein.

17. The method for producing a complex according to claim 14 or 15, wherein an egg yolk diluent is used as the egg yolk lipoprotein.

18. The method for producing a complex according to claim 14 or 15, wherein 185 parts by weight or less of phytosterol is used based on 1 part by weight of the egg yolk solid content, except that the amount of phytosterol is 0.

19. The method for producing a complex according to claim 14 or 15, wherein the average particle size of the phytosterol is 50 μm or less.

20. The method for producing a complex according to claim 14 or 15, wherein the phytosterol in the form of a sheet or powder is mixed by stirring.