(19)
(11)EP 3 323 421 B1

(12)EUROPEAN PATENT SPECIFICATION

(45)Mention of the grant of the patent:
13.01.2021 Bulletin 2021/02

(21)Application number: 16851818.1

(22)Date of filing:  29.09.2016
(51)International Patent Classification (IPC): 
A61K 8/9789(2017.01)
A23L 33/105(2016.01)
A61P 29/00(2006.01)
A61P 39/06(2006.01)
A61K 36/63(2006.01)
A61K 8/97(2017.01)
A61P 31/04(2006.01)
A61Q 19/00(2006.01)
(86)International application number:
PCT/JP2016/078955
(87)International publication number:
WO 2017/057647 (06.04.2017 Gazette  2017/14)

(54)

METHOD FOR PRODUCING AN OLIVE LEAF EXTRACT

VERFAHREN ZUR HERSTELLUNG EINES OLIVENBLATTEXTRAKTES

PROCÉDÉ DE PRODUCTION D'UN EXTRAIT DE FEUILLES D'OLIVIER


(84)Designated Contracting States:
AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

(30)Priority: 01.10.2015 JP 2015195514

(43)Date of publication of application:
23.05.2018 Bulletin 2018/21

(73)Proprietor: Shodoshima Healthy Land Co. Ltd.
Tonosho-cho Shouzu-gun Kagawa 7614-113 (JP)

(72)Inventors:
  • YAGYU Toshihiro
    Shozu-gun Kagawa 761-4113 (JP)
  • KISHIMOTO Norihito
    Shozu-gun Kagawa 761-4111 (JP)

(74)Representative: Abel & Imray 
Westpoint Building James Street West
Bath BA1 2DA
Bath BA1 2DA (GB)


(56)References cited: : 
EP-A1- 1 790 234
JP-A- 2002 128 678
JP-A- 2003 335 693
JP-A- 2011 125 301
KR-B1- 101 049 776
WO-A1-2014/140312
JP-A- 2003 210 137
JP-A- 2008 201 715
JP-A- 2012 517 824
  
      
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description

    TECHNICAL FIELD



    [0001] The present invention relates to a method of producing an olive leaf extract that is derived mainly from olive leaves, contains a high concentration of oleuropein, and has excellent functionality.

    BACKGROUND ART



    [0002] Olive leaves have been known to have a vitamin A content much higher than the olive fruit and be rich in vitamin E as an antioxidant as well as chlorophyll and others having an anti-inflammatory action and deodorant and antibacterial actions.

    [0003] It is also known that since excellent components such as vitamin A, vitamin E, and chlorophyll contained in olive leaves are efficiently incorporated in the extracted oil obtained by grinding the olive fruit and olive leaves together for extraction, the extracted oil includes a large amount of excellent components such as vitamin A, vitamin E, and chlorophyll in a natural form, compared with olive oil extract derived only from the olive fruit.

    [0004] The olive fruit and leaves contain polyphenols, and their health enhancing actions have also drawn attention nowadays. Oleuropein, which is a kind of polyphenols contained in olive leaves, particularly has a very high antioxidant potency, and the effect of preventing and ameliorating various diseases have been noted.

    [0005] As an example of the use of such olive leaves, Patent Document 1 discloses a method of producing an olive leaf extract including oleuropein by drying and grinding olive leaves, followed by extraction using water, water containing citric acid, or water containing peptide as an extraction solvent.

    Prior Art Documents


    Patent Document



    [0006] Patent Document 1: Japanese Patent Application Publication No. 2011-125301 (JP 2011-125301 A). KR 101049776B1 meanwhile discloses a cosmetic composition for preventing alopecia, which may optionally contain a small quantity of olive leaf; whilst EP-A-1790234 discloses a feed additive which may comprise a combination of olive leaf extract and wine extract.

    SUMMARY OF THE INVENTION


    Problem to be Solved by the Invention



    [0007] Unfortunately, the method disclosed in Patent Document 1 focuses on reduction in astringency and bitterness and does not disclose the optimums including extraction conditions in view of how to extract a high concentration of oleuropein.

    [0008] The present invention is made in view of such a problem and an object of the present invention is to provide a method of producing an olive leaf extract containing a high concentration of oleuropein.

    Means for Solving the Problem



    [0009] In order to solve the problem above, a method of producing an olive leaf extract according to the present invention comprises a first step of grinding dried olive leaves and a second step of mixing grapes with the ground olive leaves and then extracting an olive leaf extract using an extraction solvent. In the second step, the extraction solvent is water, alcohol, or a combination thereof, and extraction is performed at 70°C or higher.

    [0010] In the method of producing an olive leaf extract according to the present invention, the amount of the olive leaves added with respect to the extraction solvent may be not less than 15% and not more than 35% by weight.

    [0011] In the method of producing an olive leaf extract according to the present invention, the cultivar of the olive leaves may be at least one selected from the group consisting of Lucca, Mission, Nevadillo Blanco, and Manzanillo.

    Effects of the Invention



    [0012] The present invention can provide a method of producing an olive leaf extract containing a high concentration of oleuropein.

    MODES FOR CARRYING OUT THE INVENTION



    [0013] The present invention provides a method of producing an olive leaf extract. The olive leaf extract is an extract derived from olive leaves and contains polyphenols such as oleuropein and hydroxytyrosol. Oleuropein and hydroxytyrosol are known as phenolic compounds having antioxidant potency, and their effects of preventing and ameliorating diseases because of the antioxidant potency have been confirmed.

    [0014] The method of producing an olive leaf extract according to the present invention comprises a first step of grinding dried olive leaves and a second step of extracting an olive leaf extract from the ground olive leaves using an extraction solvent.

    [0015] The first step is a step of grinding dried olive leaves. In the present description, "grinding" refers to physically crushing an object to reduce the size of the object, for example, physically crushing an object into fine particles, small pieces, powder, or the like. The method of drying olive leaves and the method of grinding olive leaves are not limited to particular methods, and any method can be used.

    [0016] Examples of the cultivars of olive leaves that may be used in the present invention include Lucca, Mission, Nevadillo Blanco, Manzanillo, Amellenque, Arbequina, Ascolana Terena, Ascolano, Azapa, Barnea, Barouni, Biancolilla, Bidh El Hamman, Blanqueta, Caillet Blane, Carolea, Cayonne, Chemilali, Chitoni, Cipressino, Coratina, Cornicabra, Correggiola, Cucco, Gigante di Cerignola, Frantoio, Glappolo, Gordal, Hardy's Mammoth, Hojiblanca, Itrana, Jumbo Kalamata, Kalamata, Koroneiki, Leccino, Leccio del Corno, Liani, Lucques, Manzanilla, Maurino, Michellenque, Moraiolo, Nabali Mohassan, Nab Tamri, Negral, Nocellara del Belice, Obliza, Oblonga, Paragon, Pendolino, Picual, Redding picholine, Redounan, Saurin large leaf, Saurin medium leaf, Saurin small leaf, Sevillano, Sorani, South Australian Verdale, St. Catherin, Taggiasca, Tanche, Tiny Oil Kalamata, Tsunati, Verdale, Wagga Verdale, Zarza, Olivière, and FS17. In the present invention, the cultivars of olive leaves may be used singly or in combination of two or more.

    [0017] The picking seasons for olive leaves are preferably, for example, but not limited to, the times around December when the olive fruit contains a high oil content in regions such as Japan in the Northern Hemisphere, or preferably the times after the olive fruit is fully ripe and harvested.

    [0018] The second step is a step of extracting an olive leaf extract from the ground olive leaves using an extraction solvent.

    [0019] The extraction solvent is water, alcohol, or a combination thereof. That is, the extraction solvent is water, alcohol, or water including alcohol. In the present invention, examples of the alcohol include methanol, ethanol, isopropyl alcohol, butanol, glycerol, ethylene glycol, propylene glycol, 1,3-butylene glycol, and polyethylene glycol. The alcohol may be alcohol beverages such as sake and shochu (distilled spirit). Alcohols may be used singly or in combination of two or more. The extraction solvent may be, for example, water, ethanol or 1,3-butylene glycol, or a combination thereof.

    [0020] In the second step, the extraction temperature is 70°C or higher. The extraction at 70°C or higher yields an olive leaf extract with a high oleuropein content, as illustrated in Examples later. The upper limit of the extraction temperature is, for example, but not limited to, 100°C or lower.

    [0021] The amount of olive leaves added with respect to the extraction solvent is not less than 15% by weight and not more than 35% by weight to obtain an olive leaf extract with a high oleuropein content and a high anti-glycation potency, as illustrated in Examples later.

    [0022] In the second step, extraction may be performed using an extraction solvent after fruits are mixed with the ground olive leaves. Fruit itself may be used as the fruits, or fruit skin, flesh, juice, crushed product, squeezed juice, residue, or a combination thereof may be used.

    [0023] In the present invention, examples of the fruits include grapes, oranges, tangerines, mandarins, grapefruits, lemons, limes, apples, peaches, strawberries, blueberries, cranberries, elderberries, bilberries, blackberries, raspberries, bananas, mangos, kiwis, pomegranates, persimmons, tomatoes, pears, cherries, plums, pineapples, loquats, and quinces. The fruits are preferably grapes. The grapes include, for example, red grapes, white grapes, and black grapes. In the present invention, fruits may be used singly or in combination of two or more.

    [0024] By mixing the fruits with the olive leaves, an olive leaf extract can be extracted that contains polyphenols exceeding the sum of the theoretical value of polyphenols simply extracted from the olive leaves and the theoretical value of polyphenols extracted from the fruits. The fruits are mixed with the olive leaves to acidify water or the like as the extraction solvent in the extraction process, which presumably increases the polyphenol concentration in the obtained extract.

    [0025] The olive leaf extract produced by the method of producing an olive leaf extract according to the present invention contains a higher concentration of oleuropein compared with conventional ones. The olive leaf extract produced by the method according to the present invention thus has a high antioxidant potency and can be used in a variety of medicines, foods, and cosmetics using this antioxidant potency. In addition, the olive leaf extract produced by the method according to the present invention can be used as an anti-glycation agent because of its high anti-glycation potency.

    Examples


    (Measurement Method)



    [0026] In measuring the total polyphenol content, the Folin-Ciocalteu method was used. This method uses the Folin's phenol reagent, which is reduced by phenolic hydroxy group to change color. In measuring the oleuropein content, HPLC analysis was conducted. This is called high-performance liquid chromatography and is a process for separating a certain substance in a system including a stationary phase and a mobile phase.

    [0027] In measuring the anti-glycation potency, the samples were reacted with a BSA-fructose solution to produce AGEs (Advanced Glycation End Products) solution, and the amount of AGEs in the AGEs solution was measured through the competitive method.

    [0028] Furthermore, in measuring the antioxidant potency, ORAC (Oxygen Radical Absorbance Capacity) was determined (reference: Wu, X. et al., J. Agric. Food Chem., m 2004, 52, 4026-4037. The activity exhibited by 1 µmol of Trolox was used as a unit).

    (Olive Leaf and Extraction Solvent)



    [0029] Tables 1 to 3 list the polyphenol concentration and the like of the olive leaf extracts produced through extraction from olive raw leaves, steamed leaves, and dried leaves with water, a 1,3-butylene glycol solution, or an ethanol solution. Leaves ground after drying were used as the dried leaves. The cultivar of the olive leaves used here was Mission, the extraction temperature was 50°C-60°C, the extraction time was 5 hours, and the amount of leaves added was 10% by weight with respect to the extraction solvent. Then, the total polyphenol content (mg/100g), the oleuropein content (mg/100g), and the anti-glycation potency (IC50) of the olive leaf extract produced through extraction using each of water, 30% BG (BG is butylene glycol), 50% BG, 80% BG, 50% EtOH (EtOH is ethanol), and 100% EtOH were measured.
    [Table 1]
    Use of raw leavesTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    Water 127 20 0
    30% BG 239 25 0
    50% BG 216 25 0
    80% BG 207 26 0
    50% EtOH 257 29 20
    100% EtOH 163 27 11
    [Table 2]
    Use of steamed leavesTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    Water 190 29 14
    30% BG 307 109 26
    50% BG 279 59 27
    80% BG 259 59 13
    50% EtOH 347 109 30
    100% EtOH 243 99 18
    [Table 3]
    Use of dried leavesTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    Water 248 39 26
    30% BG 378 46 33
    50% BG 414 238 29
    80% BG 423 329 30
    50% EtOH 502 314 33
    100% EtOH 339 292 21


    [0030] As listed in Tables 1 to 3, it was found that all of the total polyphenol content, the oleuropein content, and the anti-glycation potency are high when the olive leaf extract is obtained from dried leaves, compared with raw leaves and steamed leaves. When the extractions using water, water containing 1,3-butylene glycol, water containing ethanol, and 100% ethanol as an extraction solvent from the olive leaves ground after drying were compared, it was found that a sufficient total polyphenol content, a sufficient oleuropein content, and a sufficient anti-glycation potency can be obtained even using water as an extraction solvent.

    (Cultivars of Olive Leaves)



    [0031] Table 4 lists the polyphenol concentration and the like of the olive leaf extracts produced through extraction with water from various cultivars of olive leaves ground after drying. The cultivars of olive leaves used here were Mission, Lucca, Nevadillo Blanco, and Manzanillo. With the basic extraction conditions: the extraction temperature of 50°C to 60°C; the extraction time of 5 hours; and the amount of leaves added 10% by weight with respect to the extraction solvent, the total polyphenol content (mg/100g), the oleuropein content (mg/100g), and the anti-glycation potency (IC50) of the olive leaf extracts produced from various cultivars of olive leaves were measured.
    [Table 4]
    Olive cultivarTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    Mission 248 39 26
    Lucca 471 548 30
    Nevadillo Blanco 381 289 34
    Manzanillo 423 330 41


    [0032] When the polyphenol concentration and the like for various cultivars were measured in this manner, a favorable result was obtained for all of Lucca, Mission, Nevadillo Blanco, and Manzanillo. In particular, the most favorable values were obtained for Lucca. The olive leaves may be selected in view of cost effectiveness.

    (Extraction Temperature)



    [0033] Table 5 lists the polyphenol concentration and the like of the olive leaf extracts produced through extraction with water at various temperatures from olive leaves ground after drying. The cultivar of olive leaves used here was Mission, the extraction solvent was water, the extraction temperature was changed stepwise in the range from 30°C to 100°C, the extraction time was 5 hours, and the amount of leaves added was 10% by weight with respect to the extraction solvent. Then, the total polyphenol content (mg/100g), the oleuropein content (mg/100g), and the anti-glycation potency (IC50) of the olive leaf extracts produced through extraction at various extraction temperatures were measured.
    [Table 5]
    Extraction temperatureTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    30°C-40°C 221 17 24
    40°C-50°C 223 18 28
    50°C-60°C 248 39 26
    60°C-70°C 306 58 32
    70°C-80°C 380 405 28
    80°C-90°C 408 489 30
    90°C 100°C 342 312 31


    [0034] When the polyphenol concentrations of the olive leaf extracts extracted at various temperatures were compared in this manner, it was found that the oleuropein content noticeably increases at temperatures exceeding 70°C. It can therefore be said that 70°C or higher is the optimum condition as the extraction temperature.

    (Extraction Time)



    [0035] Table 6 lists the polyphenol concentration and the like of the olive leaf extracts produced through extraction with water from olive leaves ground after drying for various extraction times. The cultivar of olive leaves used here was Mission, the extraction solvent was water, the extraction temperature was from 50°C to 60°C, the extraction time was changed stepwise from 0.5 hour to 12 hours, and the amount of leaves added was 10% by weight with respect to the extraction solvent. Then, the total polyphenol content (mg/100g), the oleuropein content (mg/100g), and the anti-glycation potency (IC50) of the olive leaf extract produced through extraction with various extraction times were measured.
    [Table 6]
    Extraction timeTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    0.5 hour 235 ND 16
    1 hour 243 84 13
    2 hours 242 42 15
    3 hours 262 32 27
    5 hours 248 39 26
    7 hours 274 36 27
    12 hours 253 37 22


    [0036] When the polyphenol concentrations and the like of the olive leaf extracts extracted with the extraction time changed stepwise, such as 0.5 hour, 1 hour, 2 hours, 3 hours, 5 hours, 7 hours, and 12 hours were compared in this manner, it was found that any extraction time equal to or longer than 1 hour yields a favorable result in respect of the total polyphenol, the oleuropein content, and the anti-glycation potency.

    (Amount of Olive Leaf Added)



    [0037] Table 7 lists the polyphenol concentration and the like of the olive leaf extracts produced through extraction with water from various added amounts (%) of olive leaves ground after drying. The cultivar of olive leaves used here was Mission, the extraction solvent was water, the extraction temperature was from 50°C to 60°C, the extraction time was 5 hours, and the amount of leaves added was changed stepwise with respect to the extraction solvent. The total polyphenol content (mg/100g), the oleuropein content (mg/100g), and the anti-glycation potency (IC50) of the olive leaf extracts produced through extraction from various amounts of leaves added were measured. In conversion into the amount of raw leaves, given that the weight is reduced to 50% to 55% in the drying process, the dried leaf weight is considered as the raw leaf × 0.5 to 0.55.
    [Table 7]
    Amount of leaves added*Total polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    5% 133 89 ND
    10% 248 39 26
    20% 493 279 29
    30% 685 318 58
    40% 735 53 52


    [0038] It was confirmed that the total amount of polyphenols significantly increases as the amount of olive leaves added increases. Then it was proven that when the amount of leaves added is 20% by weight, the rate of increase of the oleuropein content is extremely high compared with when the amount of leaves added is 10% by weight. It was also found that when the amount of leaves added is 20% by weight to 30% by weight, a favorable result can be obtained in respect of the oleuropein content and the anti-glycation potency. It can therefore be said that not less than 15% by weight to not more than 35% by weight is the optimum condition for the amount of leaves added.

    [0039] Based on the foregoing, in the method of producing an olive leaf extract according to the present invention, the optimum conditions for obtaining an extract that contains a high concentration of polyphenols and also achieves sufficient effects in respect of the anti-glycation potency are as follows.

    - First condition: extraction solvent



    [0040] Water, alcohol, and a combination thereof can be used as the extraction solvent. For example, water, 1,3-butylene glycol, ethanol, and any combination thereof can be used. Even when water is used, a sufficient total polyphenol content, a sufficient oleuropein content, and a sufficient anti-glycation potency can be obtained.

    - Second condition: cultivar of olive leaves



    [0041] At least Lucca, Mission, Nevadillo Blanco, or Manzanillo can be used as the olive cultivar, although not limited thereto. In particular, Lucca is most suitable in view of a high concentration of the polyphenol content.

    - Third condition: extraction temperature



    [0042] It is found that the oleuropein content significantly increases at the extraction temperature exceeding 70°C, and 70°C or higher is most suitable.

    - Fourth condition: extraction time



    [0043] When the extraction time is, but not limited to, 1 hour or longer, a sufficient total polyphenol content, a sufficient oleuropein content and a sufficient anti-glycation potency can be obtained.

    - Fifth condition: the amount of leaves added



    [0044] When the amount of leaves added is, but not limited to, 15% by weight to 35% by weight, a favorable result can be obtained in respect of the oleuropein content and the anti-glycation potency.

    [0045] By satisfying at least one or any combination of two or more of the first condition to the fifth condition above, or all of them, an olive leaf extract can be produced that has a sufficiently high total polyphenol content, a sufficiently high oleuropein content, and a sufficiently high anti-glycation potency.

    (Example 1)



    [0046] Table 8 lists the total polyphenol content, the oleuropein content, and the anti-glycation potency in the olive leaf extract extracted under the first to fifth conditions above. More specifically, on the premise that the olive leaves ground after drying are used, the cultivar of olive leaves used was Lucca, Mission, Nevadillo Blanco, or Manzanillo, the extraction solvent was water, the extraction temperature was from 70°C to 80°C, the extraction time was 3 hours, and the amount of leaves added was 20% by weight with respect to the extraction solvent. The total polyphenol content (mg/100g), the oleuropein content (mg/100g), and the anti-glycation potency (IC50) of the olive leaf extracts produced through extraction under such conditions were measured.
    [Table 8]
    Optimum conditionsTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)Anti-glycation potency (IC50)
    Mission 670 73 43
    Lucca 1360 1857 72
    Nevadillo Blanco 960 1000 66
    Manzanillo 1221 1334 88


    [0047] As illustrated above, under the conditions above, for all of the four cultivars, the total polyphenol content has a high value, and the oleuropein content has a high value, especially for Lucca. All of the four cultivars exhibit high values for the anti-glycation potency. By comparison with Table 4 listing the result of measurement obtained under the basic extraction conditions, all of the total polyphenol content, the oleuropein content, and the anti-glycation potency are increased, which proves that the effect of the extraction under the extraction conditions above is extremely high.

    (Example 2)



    [0048] In Example 2, with the first to fifth conditions above as extraction conditions, the olive leaves ground after drying were mixed with red grape skin and subjected to extraction with water. The cultivar used was Mission, the extraction temperature was from 70°C to 80°C, the extraction time was 3 hours, the amount of leaves added was 20% by weight with respect to the extraction solvent, and the amount of grape skin added was 10% by weight with respect to the extraction solvent. The result is listed in Table 9.
    [Table 9]
    Mixture extraction/WaterTotal polyphenol content (mg/100g)
    Red grape skin 226
    Olive leaves 499
    Red grape skin + olive leaves 853


    [0049] As illustrated above, the extraction of the olive leaf extract was confirmed that it contains polyphenols exceeding the sum of the theoretical value of polyphenols simply extracted from olive leaves and the theoretical value of polyphenols extracted from the skin of grapes as fruit.

    (Example 3)



    [0050] In Example 3, with the first to fifth conditions above as extraction conditions, the cultivar used was changed to Lucca, and the olive leaves ground after drying were mixed with the skin of red grapes and subjected to extraction with water. The extraction temperature was from 70°C to 80°C, the extraction time was 3 hours, the amount of leaves added was 20% by weight with respect to the extraction solvent, and the amount of grape skin added was 10% by weight with respect to the extraction solvent. The result is listed in Table 10.
    [Table 10]
    Mixture extraction/WaterTotal polyphenol content (mg/100g)Oleuropein content (mg/100g)
    Olive leaves 1199 1888
    Red grape skin + olive leaves 1648 2765


    [0051] Also in this case, the extraction of the olive leaf extract was confirmed that it contains polyphenols exceeding the sum of the theoretical value of polyphenols simply extracted from olive leaves and the theoretical value of polyphenols extracted from the skin of grapes as fruit.

    (Example 4)



    [0052] In Example 4, with the first to fifth conditions above as extraction conditions, the cultivar used was changed to Lucca, and the olive leaves ground after drying were mixed with the skin of red grapes and subjected to extraction with 30% 1,3-butylene glycol. The extraction temperature was from 70°C to 80°C, the extraction time was 3 hours, the amount of leaves added was 20% by weight with respect to the extraction solvent, and the amount of grape skin added was 10% by weight with respect to the extraction solvent. The result is listed in Table 11.
    [Table 11]
    Mixture extraction/30% BGTotal polyphenol content (mg/100g)
    Red grape skin 465
    Olive leaves 1106
    Red grape skin + olive leaves 3235


    [0053] Also in this case, the extraction of the olive leaf extract was confirmed that it contains polyphenols exceeding the sum of the theoretical value of polyphenols simply extracted from olive leaves and the theoretical value of polyphenols extracted from the skin of grapes as fruit.

    (Example 5)



    [0054] In Example 5, the antioxidant potency of the olive leaf extract obtained from olive leaves alone and that of the olive leaf extract (mixture extract) obtained from the mixture of olive leaves and red grape skin were measured. Each of the ORAC value (µmol TE/g) obtained through the measurement is listed in Table 12.
    [Table 12]
     ORAC value (µmol TE/g)
    Olive leaf extract 98
    Mixture extract of red grape skin and olive leaf 140


    [0055] As illustrated above, it was confirmed that the mixture extract of red grape skin and olive leaves has an antioxidant potency significantly higher than the olive leaf extract.

    INDUSTRIAL APPLICABILITY



    [0056] The present invention can be used in production of an olive leaf extract containing a high concentration of oleuropein, and medicines, foods, and cosmetics containing the same.


    Claims

    1. A method of producing an olive leaf extract, the method comprising:

    a first step of grinding dried olive leaves; and

    a second step of mixing grapes with the ground olive leaves and then extracting an olive leaf extract using an extraction solvent, wherein

    in the second step, the extraction solvent is water, alcohol, or a combination thereof, and extraction is performed at 70°C or higher; and wherein the amount of the olive leaves added with respect to the extraction solvent is not less than 15% by weight and not more than 35% by weight.


     
    2. The method of producing an olive leaf extract according to claim 1, wherein a cultivar of the olive leaves is at least one selected from the group consisting of Lucca, Mission, Nevadillo Blanco, and Manzanillo.
     


    Ansprüche

    1. Verfahren zur Herstellung eines Olivenblätterextrakts, wobei das Verfahren enthält:

    einen ersten Schritt des Mahlens der getrockneten Olivenblätter; und

    einen zweiten Schritt des Mischens von Trauben mit den gemahlenen Olivenblättern und des darauffolgenden Extrahierens des Olivenblätterextrakts mit einem Extraktionslösemittel, wobei

    das Extraktionslösemittel im zweiten Schritt Wasser, Alkohol, oder eine Kombination davon ist, und die Extraktion bei 70 °C oder höher durchgeführt wird; und wobei die Menge der zugegebenen Olivenblätter nicht weniger als 15 Gewichtsprozent und nicht mehr als 35 Gewichtsprozent bezogen auf das Extraktionslösemittel ist.


     
    2. Verfahren zur Herstellung eines Olivenblätterextrakts nach Anspruch 1, wobei die Sorte der Olivenblätter mindestens eine der Sorten ausgewählt aus der Gruppe bestehend aus Lucca, Mission, Nevadillo Blanco, und Manzanillo ist.
     


    Revendications

    1. Procédé de production d'un extrait de feuilles d'olivier, le procédé comprenant :

    une première étape de broyage de feuilles d'olivier séchées et

    une seconde étape de mélange de raisins avec les feuilles d'olivier broyées puis d'extraction d'un extrait de feuilles d'olivier à l'aide d'un solvant d'extraction, dans lequel

    lors de la seconde étape, le solvant d'extraction est de l'eau, un alcool, ou une combinaison de ceux-ci, et l'extraction est effectuée à 70 °C ou plus, et dans lequel la quantité des feuilles d'olivier ajoutées par rapport au solvant d'extraction n'est pas inférieure à 15 % en poids et pas supérieure à 35 % en poids.


     
    2. Procédé de production d'un extrait de feuilles d'olivier selon la revendication 1, dans lequel le cultivar des feuilles d'olivier est au moins l'un sélectionné à partir du groupe constitué de Lucca, Mission, Nevadillo Blanco et Manzanillo.
     






    Cited references

    REFERENCES CITED IN THE DESCRIPTION



    This list of references cited by the applicant is for the reader's convenience only. It does not form part of the European patent document. Even though great care has been taken in compiling the references, errors or omissions cannot be excluded and the EPO disclaims all liability in this regard.

    Patent documents cited in the description




    Non-patent literature cited in the description