JP7629686B2 - Methods for stabilizing anthocyanins - Google Patents

Description

The present invention relates to a method for stabilizing anthocyanins and an anthocyanin stabilizer that can suppress the decomposition of anthocyanins over time.

Anthocyanin is a naturally occurring antioxidant found in large amounts in berries such as blueberries, raspberries, and bilberries. It has a strong antioxidant effect and is known to be effective in relieving eye fatigue, improving eyesight, preventing eye disease, preventing metabolic syndrome, preventing hay fever, protecting and strengthening blood vessels, improving circulatory function, and as an anti-ulcer and anti-inflammatory agent, and is used in a variety of foods, beverages, and medicines.

On the other hand, anthocyanins are known to have low stability over time and are easily decomposed over time when incorporated into foods, beverages, or pharmaceuticals. Therefore, various techniques for stabilizing anthocyanins have been investigated.

For example, Patent Document 1 discloses that anthocyanins can be stabilized by adding citric acid, malic acid, and/or tartaric acid to edible oil in which anthocyanin-containing powder is dispersed. Patent Document 2 discloses that lysine and/or histidine can be used as an anthocyanin stabilizer. Patent Document 3 discloses that a composition containing anthocyanins and a specific ratio of histidine and/or ascorbic acid stabilizes anthocyanins.

Though formulation technologies aimed at stabilizing anthocyanins have been studied in the past, there has been an increasing demand in recent years for product diversification and quality improvement, and in order to meet these demands, there is a need to develop new technologies to stabilize anthocyanins.

JP 2013-135658 A JP 2016-3210 A JP 2016-96789 A

The object of the present invention is to provide an anthocyanin stabilization technology that can suppress the decomposition of anthocyanins over time.

The inventors conducted extensive research to solve the above problems and discovered that in a composition containing anthocyanin, the coexistence of anthocyanin with lecithin inhibits the decomposition of anthocyanin over time and stabilizes the anthocyanin. The present invention was completed based on this knowledge and further research.

That is, the present invention provides the following aspects.
Item 1. A method for stabilizing anthocyanin, comprising allowing the anthocyanin to coexist with lecithin in a composition containing the anthocyanin.
Item 2. The method for stabilizing anthocyanin according to Item 1, wherein lecithin is coexisted in an amount of 1 to 300 parts by weight per 100 parts by weight of anthocyanin.
Item 3. The method for stabilization according to Item 1 or 2, wherein the composition containing anthocyanin is a content of a soft capsule.
Item 4. An anthocyanin stabilizer containing lecithin as an active ingredient.

The present invention can suppress the decomposition of anthocyanins over time, thereby improving the storage stability of various products that contain anthocyanins, such as foods, beverages, and pharmaceuticals.

1. Method for stabilizing anthocyanin The stabilization method of the present invention is a method for stabilizing anthocyanin, and is characterized in that the anthocyanin and lecithin are allowed to coexist in a composition containing the anthocyanin. The stabilization method of the present invention will be described in detail below.

[Anthocyanin]
Anthocyanins are glycosides with anthocyanidin as the aglycon. There are three main types of anthocyanins, pelargodinin, cyanidin, and delphinidin, depending on the number of hydroxyl groups on the B ring of the anthocyanidin aglycon, and further, there are various classifications depending on the type of sugar bonded to them. The anthocyanins used in the present invention may have any structure.

The anthocyanins used in the present invention may be of plant origin or may be chemically synthesized, but from the standpoint of quality and productivity, plant origin is preferred.

When using anthocyanins derived from plants, the type of plant from which they are derived is not particularly limited, as long as they contain anthocyanins. Examples of such anthocyanins include blueberries, bilberries, cranberries, blackberries, raspberries, boysenberries, elderberries, lingonberries, gooseberries, asamaberries, iwakiberries, strawberries, blackcurrants, acai, grapes, prunes, haskap, red cabbage, adzuki beans, red onions, purple onions, shiso, eggplant, mallow, purple corn, sweet potatoes, potatoes, yams, black beans, black sesame seeds, red potatoes, and camellias. Anthocyanins derived from one type of plant may be used alone, or two or more types of plants may be used in combination. Among these anthocyanins, blueberries are preferred.

The anthocyanins used in the present invention may be in the form of a purified or crude product, or may be in the form of a plant extract containing anthocyanins.

Anthocyanin-containing plant extracts can be obtained by subjecting anthocyanin-containing plants as the extraction raw material to an extraction process. Specifically, anthocyanin-containing plant extracts can be obtained by subjecting anthocyanin-containing plant parts (for example, the fruit in the case of berries such as blueberries) to a solvent extraction process. Examples of extraction solvents used in the solvent extraction process include water; lower alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, and n-butanol; polyhydric alcohols such as propylene glycol and 1,3-butylene glycol; polyethers such as polyethylene glycol; and mixtures thereof. Among these extraction solvents, water, lower alcohols, and mixtures thereof are preferred, water, ethanol, and hydrous ethanol are more preferred, and ethanol is even more preferred.

The solvent extraction process may be carried out by immersing or refluxing the plant parts containing anthocyanins in the extraction solvent. After the extraction process, solid matter is removed by solid-liquid separation to obtain an extract containing anthocyanins. The obtained extract may be used as it is as a liquid anthocyanin-containing plant extract. The obtained extract may also be used as a solid anthocyanin-containing plant extract by subjecting it to filtration, purification, etc. as necessary and then drying.

In the stabilization method of the present invention, the content of anthocyanin in the composition may be appropriately set depending on the shape of the composition, the product form, etc., and may be, for example, 3.5 to 20.0% by weight, preferably 5.0 to 18.0% by weight, and more preferably 7.5 to 16.0% by weight. Note that, in the case where a plant extract containing anthocyanin is used, the description of the content of anthocyanin in this specification is a value converted into the amount of anthocyanin contained in the plant extract. The same applies to the description of the ratio of anthocyanin to lecithin described below.

[lecithin]
In the stabilization method of the present invention, in order to stabilize anthocyanin, anthocyanin and lecithin are made to coexist in the composition. Lecithin means phosphatidylcholine in the narrow sense, but means a lipid mixture mainly composed of various phospholipids in the broad sense, and in the present invention, the term "lecithin" is used in the latter sense.

The type of lecithin used in the present invention is not particularly limited, but examples include soybean lecithin, egg yolk lecithin, sunflower lecithin, rapeseed lecithin, lysolecithin (enzyme-treated lecithin), and the like. These lecithins may be used alone or in combination of two or more. Among these lecithins, soybean lecithin, egg yolk lecithin, sunflower lecithin, and rapeseed lecithin are preferred; soybean lecithin is more preferred.

In the stabilization method of the present invention, when anthocyanin and lecithin are present together in the composition, the ratio of these is 1 to 300 parts by weight, preferably 10 to 260 parts by weight, more preferably 30 to 260 parts by weight, even more preferably 65 to 190 parts by weight, and particularly preferably 60 to 130 parts by weight of lecithin per 100 parts by weight of anthocyanin.

In the stabilization method of the present invention, the content of lecithin in the composition may be appropriately set within a range that satisfies the above ratio, for example, 0.1 to 25.0% by weight, preferably 1.0 to 23.0% by weight, more preferably 2.0 to 23.0% by weight, and even more preferably 5.0 to 20.0% by weight.

[Liquid oil]
In the stabilization method of the present invention, the composition in which anthocyanin and lecithin coexist may contain liquid oil. When the composition in which anthocyanin and lecithin coexist contains liquid oil, the composition can be suitably used as the content of a soft capsule.

Liquid oils are oils that maintain a liquid form at 25° C. There are no particular limitations on the liquid oils, so long as they are usable in foods or internally administered medicines. Examples of liquid oils include safflower oil, macadamia nut oil, olive oil, rice germ oil, cottonseed oil, palm oil, almond oil, avocado oil, camellia oil, persic oil, soybean oil, sesame oil, corn oil, castor oil, jojoba oil, kukui nut oil, shea butter, evening primrose oil, perilla oil, tea seed oil, rapeseed oil, palm kernel oil, palm oil, peanut oil, sunflower oil, grape seed oil, meadowhoo oil,
Examples of the liquid oil include vegetable oils such as rice oil, soybean oil, rapeseed oil, and peanut oil; animal oils such as fish oil and fish egg oil; fatty acids, medium-chain fatty acids (about 6 to 12 carbon atoms) triglycerides, docosahexaenoic acid, and eicosapentaenoic acid. These liquid oils may be used alone or in combination of two or more. Among these liquid oils, vegetable oils are preferred.

In the stabilization method of the present invention, when liquid oil is contained in a composition in which anthocyanin and lecithin coexist, the content of the liquid oil in the composition is, for example, 15 to 85% by weight, preferably 20 to 80% by weight, and more preferably 25 to 75% by weight.

[Surfactant]
In the stabilization method of the present invention, the composition in which anthocyanin and lecithin coexist may contain a surfactant other than lecithin as necessary. In particular, when the composition in which anthocyanin and lecithin coexist contains liquid oil, it is preferable that the composition contains a surfactant other than lecithin in order to solubilize, disperse, or emulsify the water-soluble anthocyanin.

The type of surfactant is not particularly limited, so long as it is usable in foods or internally administered medicines, and may be any of nonionic surfactants, anionic surfactants, cationic surfactants, and zwitterionic surfactants. The surfactants may be used alone or in combination of two or more types.

Among these surfactants, nonionic surfactants are preferable. Specific examples of nonionic surfactants include glycerin fatty acid esters, polyoxyethylene hydrogenated castor oil, sucrose fatty acid esters, maltose fatty acid esters, maltitol fatty acid esters, lactol fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan monostearate, polyoxyethylene higher alcohol ethers, polyoxyethylene polyoxypropylene copolymers, polyoxyethylene polyoxypropylene fatty acid esters, polyglycerin fatty acid esters, etc.

In the stabilization method of the present invention, when a surfactant is contained in a composition in which anthocyanin and lecithin coexist, the content of the surfactant in the composition is, for example, 0.5 to 8.0% by weight, preferably 1.0 to 6.5% by weight, and more preferably 3.0 to 5.0% by weight.

[Other ingredients]
In the stabilization method of the present invention, the composition in which anthocyanin and lecithin coexist may contain various pharmacological ingredients, food materials, additives, etc., in addition to the above-mentioned ingredients, depending on the shape of the composition and the product form. The types of such ingredients may be appropriately selected depending on the shape of the composition in which anthocyanin and lecithin coexist and the product form, and examples thereof include water, pharmacological ingredients, refreshing agents, waxes, fatty acids, higher alcohols, monohydric lower alcohols, pH adjusters, buffers, excipients, binders, flow agents, lubricants, disintegrants, antioxidants, UV inhibitors, preservatives, powders, thickeners, acidulants, sweeteners, flavorings, and colorants. These ingredients may be used alone or in combination of two or more. The concentrations of these ingredients are appropriately set depending on the types of ingredients used, the shape of the composition, the product form, etc.

[Form of composition, product form, etc.]
In the stabilization method of the present invention, the form of the composition in which anthocyanin and lecithin coexist is not particularly limited, and may be any of solid, semi-solid, and liquid.

In the stabilization method of the present invention, the product form of the composition in which anthocyanin and lecithin coexist is not particularly limited, and examples include foods and beverages, oral medicines, etc.

The food and drink is preferably in the form of a health food, a functional food, a food for specified health uses, or the like. Specific examples of the food and drink include supplements such as salt capsules, hard capsules, syrups, jellies, tablets, granules, powders, suspensions, and the like that contain the composition; and beverages such as soft drinks, alcoholic beverages, energy drinks, coffee, tea, milk, fruit juice drinks, and refreshing drinks. A composition that contains anthocyanin and lecithin is suitable as a supplement, particularly as the content of a soft capsule.

Examples of pharmaceutical preparations for internal use include salt capsules, hard capsules, liquid powders, granules, tablets, pills, etc., which contain the composition.

2. Anthocyanin Stabilizer The anthocyanin stabilizer of the present invention is characterized by containing lecithin as an active ingredient.

The anthocyanin stabilizer of the present invention is an additive used in a composition containing anthocyanin to inhibit the decomposition of the anthocyanin over time and stabilize the anthocyanin.

In the anthocyanin stabilizer of the present invention, the type and amount of lecithin used, the type and content of the anthocyanin to be stabilized, the shape and product form of the composition containing the anthocyanin, etc. are as described in the above section "1. Method for stabilizing anthocyanin."

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

Test Example 1
An anthocyanin-containing composition (content of a soft capsule) was prepared according to the composition shown in Table 1. Specifically, a predetermined amount of glycerin fatty acid ester and soybean lecithin were first dissolved in safflower oil by heating. The resulting solution was cooled to 40°C or less, and then a predetermined amount of blueberry fruit extract was added. The mixture was finely dispersed in a homomixer to obtain an anthocyanin-containing composition.

20 g of the obtained anthocyanin-containing composition was filled into a 50 ml light-shielding glass bottle and stored at 40°C for one month. The anthocyanin content of the anthocyanin-containing composition before and after storage for one month was quantified, and the anthocyanin residual rate was calculated according to the following calculation formula.

The anthocyanin content was quantified by colorimetry. Specifically, 0.5 g of the anthocyanin-containing composition before storage and after one month of storage was first added to 60 ml of an ethanol solution containing 2% by weight of hydrochloric acid, mixed, and heated under reflux at 80-90°C for 30 minutes to hydrolyze the anthocyanin and convert it to anthocyanidin. After heating under reflux, the solution was cooled to room temperature, filtered, appropriately diluted, and then the visible absorption spectrum (350-600 nm) was measured using a spectrophotometer, and the anthocyanidin content was calculated as the amount of delphinidin from the absorbance value at the maximum absorption wavelength.

The results are shown in Table 1. As a result, when anthocyanin and lecithin were allowed to coexist, the residual rate of anthocyanin was improved after storage at 40°C for one month, confirming that lecithin has the effect of improving the stability of anthocyanin.

Test Example 2
An anthocyanin-containing composition (contents of soft capsules) having the composition shown in Table 2 was prepared. Specifically, a predetermined amount of glycerin fatty acid ester, beeswax, and soybean lecithin were first dissolved in safflower oil by heating. The obtained solution was cooled to 35°C or less, and then a predetermined amount of β-carotene, marigold pigment, and vitamin E-containing vegetable oil were added and mixed by stirring. Next, blueberry fruit extract and blackcurrant extract were added, and fine dispersion was performed using a homomixer to obtain an anthocyanin-containing composition. Next, 350 mg of the obtained anthocyanin-containing composition was coated with a soft capsule shell (containing gelatin and glycerin) to prepare a soft capsule.

The obtained soft capsules were stored for 4 months at 40°C. The anthocyanin concentration of the anthocyanin-containing composition was quantified before and after storage for 4 months, and the anthocyanin remaining rate was calculated according to the above-mentioned calculation formula. The anthocyanin concentration of the anthocyanin-containing composition (contents of the soft capsules) was quantified before and after storage for 4 months, and the anthocyanin remaining rate was calculated according to the above-mentioned calculation formula. The anthocyanin concentration was quantified by HPLC.

The results are shown in Table 2. As a result, it was confirmed that soft capsules containing a content in which anthocyanin and lecithin coexist showed a high residual rate of anthocyanin after storage for 4 months at 40°C, depending on the concentration of lecithin.

Claims (4)

A method for inhibiting decomposition of anthocyanin, comprising allowing the anthocyanin to coexist with lecithin in a composition containing the anthocyanin and 25 to 85% by weight of liquid oil. The method for inhibiting decomposition according to claim 1, in which lecithin is coexisted in an amount of 1 to 300 parts by weight per 100 parts by weight of anthocyanin. The method for inhibiting decomposition according to claim 1 or 2, wherein the composition containing anthocyanin is the content of a soft capsule. An anthocyanin decomposition inhibitor used to inhibit decomposition of anthocyanin in a composition containing anthocyanin and 25 to 85% by weight of liquid oil, comprising:
An anthocyanin decomposition inhibitor whose active ingredient is lecithin.