JP7766403B2 - Meat quality improver - Google Patents

Description

The present invention relates to a meat quality improving agent.

Meats, including livestock meats such as beef, pork, and chicken, as well as seafood such as fish and shellfish, are required to have a juicy texture with a soft and moist texture when eaten after cooking. However, when meats are cooked by deep frying, oven heating, frying pan heating, microwave heating, or the like, moisture and fat are lost from the inside of the meat due to scattering or leakage, and the texture of the cooked meat tends to become hard and dry. Furthermore, the proteins that make up the meat are denatured, shrink, and coagulate upon heating, which tends to make the hard and dry texture even more pronounced.
Various studies have been conducted to solve these problems, and proposals have included, for example, a food modifier containing oil- or fat-processed starch and egg white hydrolysate (Patent Document 1), a meat additive containing a water-soluble cellulose ether that gels when heated (Patent Document 2), a meat improver containing a protein-degrading enzyme such as protease (Patent Document 3), a powder composition for cooking meat products alone containing a polysaccharide such as xanthan gum (Patent Document 4), and a meat processing mix containing modified starch and sodium hydrogen carbonate (Patent Document 5).

Known pre-processing methods for deep-fried meat include injecting a protease solution to tenderize the meat and allowing the protease to act on the meat for a relatively long period of time. One such technique, known as marinating, has been used for a long time. The meat to be fried is then immersed in a seasoning liquid. Marinating is a method of soaking meat in a seasoning liquid to enhance flavor and retain juices, resulting in juicy, hearty fried foods. Another method, known as tumbling, is to allow the seasoning liquid to penetrate the meat without immersion. Other methods for achieving tenderness and juiciness include using a pickle solution for meat processing containing a polyglycerol fatty acid ester (Patent Document 6) and incorporating a protease into the marinade (Patent Document 7). Furthermore, it is known that the inclusion of specific diglycerides can result in fried products with a smooth texture (Patent Document 8).

On the other hand, it is widely known that pentacyclic triterpenes possess various physiological functions. For example, maslinic acid is known to have physiological functions such as anti-obesity effects (Non-Patent Document 1) and lipid metabolism-improving effects (Non-Patent Document 2). Attempts have been made to use pentacyclic triterpenes with such physiological functions in foods. Patent Document 9 discloses a food product containing a carbohydrate diet and at least one triterpene selected from the group consisting of corosolic acid, maslinic acid, and tormentic acid, as well as a food product containing such a food ingredient, and describes that the glycemic index can be reduced. Patent Document 10 discloses a skin-whitening food product, beverage, or oral skin-whitening agent containing as an active ingredient a compound selected from the group consisting of pentacyclic triterpenes, their physiologically acceptable salts, or their derivatives, and describes that melanin production is suppressed. Both inventions are based on the expectation that pentacyclic triterpenes will exert their physiological functions in the body, and there is no description or suggestion that pentacyclic triterpenes can improve the texture of meat.

Japanese Patent Application Laid-Open No. 2007-300918 JP 2011-087490 A JP 2015-211654 A Japanese Patent Application Laid-Open No. 2017-112852 WO2018/174229 Japanese Patent Application Laid-Open No. 2007-043949 Japanese Patent Application Publication No. 05-252911 Japanese Patent Application Laid-Open No. 2005-237391 Japanese Patent Application Laid-Open No. 2006-121949 Re-table No. 2002-043736

Liou CJ et al., FASEB J. 2019.Nov;33(11):11791-11803 Perez-Jimenez A et al., Phytomedicine. 2016. Nov 15;23(12):1301-1311

The objective of the present invention is to provide a meat quality improver that can produce tender and juicy processed meat foods even when meat, such as livestock meat or fish meat, is processed by cooking or other methods.

As a result of extensive research into solving the above-mentioned problems, the inventors discovered that by treating meats such as livestock and fish with a meat quality improver containing a pentacyclic triterpene, it is possible to obtain tender and juicy processed meat foods even when the meat is subjected to processing such as cooking, and thus completed the present invention.

That is, the present invention includes the following aspects.
[1] A meat quality improver containing a pentacyclic triterpene.
[2] The meat quality improving agent according to [1], wherein the pentacyclic triterpene is any one or more selected from the group consisting of oleanane-type triterpenes, ursane-type triterpenes, lupane-type triterpenes, and hopane-type triterpenes.
[3] A method for improving the quality of meat, comprising a step of treating meat with the meat quality improving agent according to [1] or [2].
[4] A method for producing processed meat foods, comprising the steps of treating meat with the meat quality improving agent according to [1] or [2] and heating the treated meat.

According to the present invention, by treating meats such as livestock meat, animal meat, and seafood meat with the meat quality improver of the present invention, it is possible to obtain processed meat foods that are tender and juicy, without the meat becoming dry and hard even after processing such as cooking. Furthermore, the physiological health benefits inherent to pentacyclic triterpenes, such as anti-obesity and improved lipid metabolism, can also be expected.

1 is an HPLC analysis chart of pentacyclic triterpene powder 1 (olive fruit-derived oleanane-type triterpene powder).

<Pentacyclic triterpenes>
Triterpenes are compounds with a basic skeleton of 30 carbon atoms, and pentacyclic triterpenes are pentacyclic compounds consisting of six isoprene units. Pentacyclic triterpenes are a type of triterpene, so they basically have 30 carbon atoms, but some have a different carbon number due to rearrangement, oxidation, elimination, or alkylation during the biosynthesis process. Pentacyclic triterpenes are generally classified by their skeleton. Examples include oleanane-type triterpenes, ursane-type triterpenes, lupane-type triterpenes, hopane-type triterpenes, selatan-type triterpenes, friedelane-type triterpenes, taraxerane-type triterpenes, taraxastan-type triterpenes, multiflorane-type triterpenes, and germanican-type triterpenes.

Oleanane-type triterpenes are pentacyclic triterpenes having the structure represented by the following formula 1 as a basic skeleton, and maslinic acid (formula 2), oleanolic acid (formula 3), glycyrrhetinic acid (formula 4), etc. are classified into this group.
(Formula 1) Oleanane triterpene
(Formula 2) Maslinic acid
(Formula 3) Oleanolic acid
(Formula 4) Glycyrrhetinic acid

Ursane-type triterpenes are pentacyclic triterpenes having the structure represented by the following formula 5 as a basic skeleton, and corosolic acid (formula 6), ursolic acid (formula 7), etc. are classified into this group.
(Formula 5) Ursane triterpenes
(Formula 6) Corosolic acid
(Formula 7) Ursolic acid

Lupane-type triterpenes are pentacyclic triterpenes having the structure represented by the following formula 8 as a basic skeleton, and betulinic acid (formula 9), alphitolic acid (formula 10), etc. are classified into this group.
(Formula 8) Lupane triterpene
(Formula 9) Betulinic acid
(Formula 10) Alphitolic acid

Hopane-type triterpenes are pentacyclic triterpenes having the structure represented by the following formula 11 as a basic skeleton, and leucotic acid (formula 12) and the like are classified into this group.
(Formula 11) Hopane triterpene
(Formula 12) Leucotylic acid

In the meat quality improving agent of the present invention, the pentacyclic triterpene is preferably any one or more selected from the group consisting of oleanane-type triterpenes, ursane-type triterpenes, lupane-type triterpenes, and hopane-type triterpenes, more preferably any one or more selected from the group consisting of oleanane-type triterpenes and ursane-type triterpenes, and even more preferably any one or more selected from the group consisting of maslinic acid, oleanolic acid, and ursolic acid. When a carboxyl group is present in the molecule, it is generally referred to as a pentacyclic triterpene acid, and in this specification, pentacyclic triterpene acids are included in pentacyclic triterpenes.

Pentacyclic triterpenes are biosynthesized by various plants and are ubiquitously or locally present in the fruits, petals, cotyledons, stems, roots, etc. of those plants. For example, maslinic acid, which is classified as a group of oleanane-type triterpenes, is found in olive fruits and leaves, jujube, almonds, banaba leaves, sage, apples, cranberries, quince, etc. Oleanolic acid, which is classified as a group of oleanane-type triterpenes, is found in olive fruits and leaves, grapes, beets, jujube, almonds, banaba leaves, sage, hawthorn, raspberries, quince, rosemary leaves, guava, perilla leaves, blueberries, prunes, loquats, pomegranates, lemon balm, basil, rosehips, persimmons, and Swertia japonica. Ursolic acid, which is classified as a group of ursane-type triterpenes, is found in apples, basil, bilberries, cranberries, elderflower, peppermint, rosemary, lavender, oregano, thyme, hawthorn, prunes, etc.

Pentacyclic triterpenes can be obtained by extraction, fractionation, and purification from plants containing them using known methods, or by chemical synthesis. Commercially available products can also be used. They can also be used in the form of pharmacologically acceptable salts and/or derivatives. Pentacyclic triterpenes may be a single component or a mixture (combination) of two or more components.

Pentacyclic triterpenes may be used in the form of extracts of plants that contain them. Oleanane-type triterpenes are preferably used in the form of olive fruit extract or almond kernel extract, as their content is reasonably high, they have a long history of consumption, and they can be reused after oil extraction. Ursane-type triterpenes are preferably used in the form of apple peel extract, as they can be reused after juice extraction or food processing.

Olive fruit extract can be obtained using starting materials such as dried or moist semi-dried or undried olives, olive oil pomace generated during the oil extraction process, or defatted material from which oil has been removed with a fat-soluble organic solvent such as n-hexane. Specifically, when olive oil pomace is used as the starting material, pentacyclic triterpenes can be extracted with a lower alcohol capable of extracting oleanane triterpenes (e.g., ethanol, methanol, n-propanol, isopropanol, n-butanol, etc.) or a hydrous lower alcohol containing such an alcohol, optionally followed by saponification or neutralization, followed by fractionation and purification using adsorbents such as octadecyl silica (ODS), silica gel, or synthetic adsorbents, to obtain a mixture of pentacyclic triterpenes containing oleanane triterpenes as the main component. The pentacyclic triterpene fraction extracted from olive oil pomace in this way generally contains maslinic acid and oleanolic acid in a ratio of 4:1, but depending on the growing conditions and region of the olive fruit, as well as the oil extraction conditions, this ratio can range from 1:1 to 7:1. Further advanced fractionation and purification can yield individual oleanane-type triterpenes such as maslinic acid and oleanolic acid, either individually or as fractions containing trace amounts of other pentacyclic triterpenes. There are no particular limitations on the variety of olives used, and they can be used regardless of origin (domestic or foreign), for food, oil extraction, or ornamental purposes.

In the case of almond kernel extract, the starting materials can be dried or moist, semi-dried, or undried almond kernels, almond oil press cake, by-products from the manufacture of processed foods such as snacks, or by-products such as the shells and husks from almond threshing. Pentacyclic triterpenes are extracted with lower alcohols or hydrous lower alcohols, and optionally saponified or neutralized. The extract can then be fractionated and purified using adsorbents such as octadecyl silica (ODS), silica gel, or synthetic adsorbents to obtain a mixture of pentacyclic triterpenes containing maslinic acid and/or oleanolic acid as the main components. Note that almond shells are generally used as fuel, and the husks as compost.

In the case of apple peel extract, by-products such as apple juice pomace or peeled apple peels at food factories, etc., can be used as starting materials to extract pentacyclic triterpenes with lower alcohols or hydrous lower alcohols, and the extract can then be optionally saponified or neutralized, followed by fractionation and purification using adsorbents such as octadecyl silica (ODS), silica gel, or synthetic adsorbents, to obtain a mixture of pentacyclic triterpenes containing ursolic acid as the main component.

When using plants other than olive fruit, almond, or apple peel as the starting material, pentacyclic triterpenes can be obtained using a method appropriate for the plant used as the starting material. Furthermore, the types and composition ratios of the components in the resulting pentacyclic triterpenes depend on the plant used as the starting material.

Pentacyclic triterpenes have functional groups such as hydroxyl, carboxyl, aldehyde, and ketone groups, and within the plant, these functional groups are modified by various compounds or exist as intramolecularly cross-linked compounds. For example, glycyrrhizin, which is found in licorice and used as a sweetener, is a glycoside in which two glucuronic acids are ether-linked via the 3β-hydroxyl group of glycyrrhetinic acid, which is classified as an oleanane-type triterpene. Generally, compounds that modify such functional groups are eliminated during the extraction, fractionation, and purification processes, and the pentacyclic triterpenes obtained through the extraction, fractionation, and purification processes are generally in the free form.

Physiologically acceptable salts of pentacyclic triterpenes include, for example, salts with inorganic acids such as hydrochloric acid, sulfuric acid, phosphoric acid, hydrobromic acid, hydroiodic acid, nitric acid, pyrosulfuric acid, and metaphosphoric acid; salts with organic acids such as citric acid, benzoic acid, acetic acid, propionic acid, fumaric acid, maleic acid, and sulfonic acid; and alkali metal salts such as sodium salts and potassium salts.

<Meat quality improver>
The meat quality improving agent of the present invention contains a pentacyclic triterpene as an active ingredient. Preferably, the pentacyclic triterpene is any one or more selected from the group consisting of oleanane-type triterpenes, ursane-type triterpenes, lupane-type triterpenes, and hopane-type triterpenes, more preferably any one or more selected from the group consisting of oleanane-type triterpenes and ursane-type triterpenes, and even more preferably any one or more selected from the group consisting of maslinic acid, oleanolic acid, and ursolic acid.

The meat quality improving agent of the present invention may consist of a pentacyclic triterpene, and can be mixed with other ingredients to form powder, granules, tablets, liquid, etc., depending on the purpose or mode of use.
When used in the form of powder, granules, tablets, or the like, other ingredients include thickening polysaccharides such as agar, gelatin, carrageenan, gellan gum, xanthan gum, locust bean gum, tamarind seed gum, sodium alginate, pectin, curdlan, and cellulose derivatives; excipients such as dextrin, lactose, mannitol, and starch (raw starch and modified starch); anti-caking agents such as ammonium iron citrate, anhydrous sodium phosphate, calcium phosphate, anhydrous magnesium sulfate, magnesium chloride, calcium chloride, magnesium carbonate, calcium carbonate, fine silicon dioxide, and magnesium oxide; and inclusion compounds such as cyclodextrin and highly branched cyclic dextrin, and one or more of these may be appropriately selected and used.

When used in liquid form, the agent is obtained by selecting a liquid as the other ingredient and dissolving or dispersing the agent in that liquid. Such liquids include water, ethanol, propylene glycol, starch syrup, honey, etc., and may be a mixture of one or more of these.

In addition, the pentacyclic triterpene may be dissolved or dispersed in an edible oil or fat composition, or may be a W/O or O/W emulsion composition of an edible oil, water, and an emulsifier. Examples of such edible oils and fats include soybean oil, cottonseed oil, safflower oil, rice oil, corn oil, rapeseed oil, perilla oil, perilla oil, linseed oil, olive oil, sesame oil, wheat germ oil, rice bran oil, sunflower oil, peanut oil, avocado oil, egg yolk oil, fish oil, whale oil, chicken oil, lard, beef tallow, milk fat, cocoa butter, shea butter, coconut oil, palm oil, palm kernel oil, etc., as well as processed oils and fats obtained by subjecting these to one or more of the following processes: hydrogenation, fractionation, and interesterification. Examples of emulsifiers include natural emulsifiers such as lecithin (derived from soybeans, egg yolk, etc.), saponin (derived from quillaja, soybeans, etc.), and sodium caseinate (derived from milk); and food-grade synthetic emulsifiers whose lipophilic group is composed of saturated and/or unsaturated fatty acids having 8 to 22 carbon atoms and whose hydrophilic group is composed of glycerin, polyglycerin, sucrose, propylene glycol, sorbitan, etc. When making an emulsion composition, the pentacyclic triterpene, oil, water, and emulsifier can be produced by known methods using a high-pressure homogenizer, high-speed mixer, etc.

The meat quality improving agent of the present invention can be used in combination with various quality improving agents and additives other than those mentioned above, as long as the effects of the present invention are not impaired. Such ingredients include sweeteners such as glucose, fructose, sucrose, maltose, sorbitol, trehalose, and stevia; umami seasonings such as monosodium glutamate and sodium inosinate; vitamins such as ascorbic acid, thiamine, pantothenic acid, niacin, and folic acid; organic acids such as acetic acid, lactic acid, and citric acid; antioxidants such as tocopherol, propyl gallate, chlorogenic acid, sodium sulfite, butylhydroxyanisole, and catechin; colorings such as beta-carotene, caramel, and red koji pigment; extracts such as consomme, bouillon, bonito stock, and yeast extract; fermented seasonings such as yogurt, cheese, and soy sauce; enzymes such as amylase, protease, cellulase, lipase, and transglutaminase; flavorings; alcoholic beverages; oligosaccharides; stabilizers; eggs; dairy products; preservatives; fruit juice; and spices.

The content of the pentacyclic triterpene in the meat quality improving agent of the present invention is not particularly limited and can be appropriately adjusted so as to obtain the effects of the present invention when a processed meat food is produced. For example, it may be 1% by mass or more, preferably 5% by mass or more, and more preferably 10% by mass or more, based on the total amount of the meat quality improving agent.
The meat quality improving agent of the present invention can be produced by mixing and/or dissolving the pentacyclic triterpene together with the above-mentioned optional components, and there are no particular limitations on the production method.

There are no particular limitations on the type of meat to which the meat quality improving agent of the present invention can be applied, and any commonly eaten meat can be suitably applied.
Examples of such meat include mammals such as beef, pork, horse, sheep, goat, rabbit, boar, and deer; birds such as chicken, quail, duck, goose, wild goat, turkey, and ostrich; fish such as tuna, salmon, cod, sea bream, swordfish, sardines, mackerel, horse mackerel, saury, eel, carp, and crucian carp; marine mammals such as whales, dolphins, seals, and walruses; reptiles such as crocodiles, turtles, and snakes; amphibians such as frogs and salamanders; mollusks such as octopus and squid; shellfish such as scallops, clams, and hard clams; and crustaceans such as spiny lobster and prawn. These meats may be used alone or in combination of two or more types.
There are no particular limitations on the part of the meat, and examples thereof include beef sirloin, fillet, loin, belly, rib roast, rump, etc., pork loin, fillet, belly, thigh, etc., and chicken breast, thigh, wing, chicken fillet, etc. There are also no particular limitations on the shape of the meat, and examples thereof include meat chunks in the form of blocks, fillets, dices, sticks, slices, minced meat, surimi, etc.

<Meat quality improvement method>
The meat quality improving method of the present invention comprises a step of treating meat with a meat quality improving agent containing the pentacyclic triterpene of the present invention. Here, "treating meat with a meat quality improving agent" is not particularly limited as long as it is a treatment method that can bring the pentacyclic triterpene into contact with the meat, and examples include injection (mechanical injection of a seasoning or the like into meat), tumbling (mechanical penetration of a seasoning or the like into meat), marinating (adding a seasoning or the like to meat and allowing it to stand for marinating), spraying (mechanical spraying of a seasoning or the like onto meat), coating (applying a seasoning or the like onto meat with a brush or the like), sprinkling (coating meat with a powdered seasoning or the like), and stewing (stewing meat with stock or the like), and one or more methods selected from these methods can be used.

The amount of meat quality improver used can be appropriately set taking into consideration the type, quality, size, shape, and meat quality improvement method used of the meat used. From the viewpoint of effectively improving meat quality, the amount of pentacyclic triterpene used is 0.001 parts by mass or more, preferably 0.003 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more per 100 parts by mass of meat. There is no particular upper limit to the amount of pentacyclic triterpene used, but from the viewpoint of production efficiency, it is 20 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less per 100 parts by mass of meat. By using a pentacyclic triterpene within this range, the quality of the meat can be improved satisfactorily.
The treatment time for meat with the meat quality improving agent (pentacyclic triterpene) is not particularly limited, but is preferably 10 seconds to 24 hours, more preferably 1 minute to 2 hours, and even more preferably 2 minutes to 1 hour. The longer the treatment time, the greater the meat quality improvement effect, but from the perspective of production efficiency, it is desirable to keep the treatment time to 1 hour or less.

<Method of manufacturing processed meat foods>
In the present invention, processed meat foods refer to foods in which meat is processed by heating.
The method for producing processed meat foods of the present invention comprises the steps of treating meat with the meat quality improving agent and heating the meat that has been improved with the meat quality improving agent.
The processed meat foods obtainable by the method for producing processed meat foods of the present invention are not particularly limited, and examples include fried meats and non-fried meats such as fried chicken, Tatsuta-age, fried chicken, pork cutlet, beef cutlet, fried tuna, fried salmon, fried shrimp, fried scallops, and fritters; grilled meats such as steak, roast beef, roast pork, yakitori, and grilled fish; simmered meats such as curry, stew, and pot-au-feu; salted and/or smoked meats such as boneless ham, bacon, sausage, and smoked salmon; minced meats such as hamburger steak, meatballs, meatballs, fish cakes, kamaboko, and chikuwa; and dried meats such as beef jerky and filleted horse mackerel.
Among these, from the viewpoint of obtaining the effects of the present invention well, fried foods, grilled meats, and stewed meats are preferred, and fried meats and grilled meats are more preferred. Also preferred are processed meat foods using chunks of meat that have not been ground or minced.

In the method for producing processed meat foods of the present invention, the method of treatment in the step of treating meat with a meat quality improver is not particularly limited, and examples include injection (a process of mechanically injecting a seasoning liquid or the like into meat), tumbling (a process of mechanically permeating a seasoning liquid or the like into meat), marinating (a process of adding a seasoning liquid or the like to meat and leaving it to marinate), spraying (a process of mechanically spraying a seasoning liquid or the like onto meat), coating (a process of applying a seasoning liquid or the like onto meat using a brush or the like), sprinkling (a process of covering meat with a powdered seasoning or the like), stewing (a process of stewing meat with stock or the like), and one or more methods selected from these methods can be used.
The amount of meat quality improver used can be appropriately set taking into consideration the type, quality, size, shape, and meat quality improvement method used of the meat used. From the viewpoint of effectively improving meat quality, the amount of pentacyclic triterpene used is 0.001 parts by mass or more, preferably 0.003 parts by mass or more, more preferably 0.01 parts by mass or more, even more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of meat used in the production of processed meat foods. There is no particular upper limit to the amount of pentacyclic triterpene used, but from the viewpoint of production efficiency, it is 20 parts by mass or less, preferably 10 parts by mass or less, and more preferably 5 parts by mass or less, per 100 parts by mass of meat used in the production of processed meat foods. By using a pentacyclic triterpene within this range, the quality of the meat can be improved satisfactorily.
The treatment time for meat with the meat quality improving agent is not particularly limited, but is preferably 10 seconds to 24 hours, more preferably 1 minute to 2 hours, and even more preferably 2 minutes to 1 hour. The longer the treatment time, the greater the meat quality improvement effect, but from the perspective of production efficiency, it is desirable to keep the treatment time to 1 hour or less.

The method for producing processed meat foods of the present invention further includes a step of heating the meat treated with the meat quality improving agent. The heating method is not particularly limited, and examples include frying, frying pan heating, oven heating, direct flame heating, smoking, steam heating, steam convection heating, superheated steam heating, stewing, and microwave heating. The heating temperature is also not particularly limited, and can be adjusted appropriately depending on the processed meat food being produced. For example, the temperature is 160-220°C for frying, 170-240°C for frying pan heating, 70-300°C for oven heating, 30-100°C for smoking heating, 50-100°C for steam heating, 120-300°C for steam convection heating, 100-350°C for superheated steam heating, and 50-100°C for stewing.

The resulting processed meat food can be flash-frozen and stored frozen, and reheated with or without thawing. For example, in the case of fried chicken, chicken thigh meat to which the meat quality improving agent has been applied can be coated with a batter, fried in a heated oil bath, allowed to cool, and then flash-frozen at -40°C to produce frozen fried chicken, which can then be stored in the freezer compartment of a household refrigerator/freezer for 10 days and re-fried in a heated oil bath without thawing, or heated in a microwave oven to produce fried chicken.

Furthermore, in the present invention, after treatment with a meat quality improving agent, frozen processed meat or refrigerated processed meat can be produced without heating. For example, in the case of fried chicken, chicken thigh meat treated with a meat quality improving agent can be coated with a coating material, placed in a container, and then quickly frozen at -40°C to produce frozen, unfried fried chicken. After storing the chicken in the freezer compartment of a household refrigerator-freezer, the chicken can be deep-fried in a heated oil bath, either thawed or unthawed.

The following examples are provided to specifically explain the present invention, but the present invention is not limited to the following examples.

<Production Example 1: Production of Pentacyclic Triterpene Powder 1>
(1) Olive oil was extracted from olive fruits by cold pressing to obtain olive fruit oil cake.
(2) 250 parts by mass of 90% aqueous ethanol (v/v) was added to 100 parts by mass of olive fruit oil press cake, and the mixture was heated at 70°C for 2 hours with stirring. The liquid portion obtained by solid-liquid separation was distilled under reduced pressure using an evaporator to obtain a concentrated liquid.
(3) The concentrate was dispersed in water and subjected to column chromatography using a synthetic adsorption resin, Amberlite XAD4 (Organo Corporation), as a carrier. A triterpene-rich fraction was isolated by stepwise elution in 10% increments from 50% aqueous ethanol to 100% ethanol.
(4) The triterpene-rich fraction was distilled under reduced pressure to prepare an oily olive fruit-derived triterpene-containing liquid.
(5) 100 parts by mass of this triterpene-containing liquid was added with 100 parts by mass of 20% aqueous ethanol, mixed thoroughly to dissolve, and left to stand overnight at 4°C to cause precipitation. The precipitate was collected by filtration, washed, dried under reduced pressure, and then powdered using a pin mill to obtain pentacyclic triterpene powder 1.
(6) 1 g of Pentacyclic Triterpene Powder 1 was dissolved in methanol and subjected to HPLC analysis. Figure 1 shows the HPLC chart, with peak A representing maslinic acid and peak B representing oleanolic acid. Peak identification was performed by comparison of retention times with those of a standard and LC/MS analysis, and quantitative values were calculated based on the peak area of the standard. As a result, it was found that Pentacyclic Triterpene Powder 1 contained 50% by mass of maslinic acid and 30% by mass of oleanolic acid (both oleanane-type triterpenes derived from olive fruit).

<Production Example 2: Production of Pentacyclic Triterpene Powder 2>
(1) An oil-like liquid containing olive fruit-derived triterpene was prepared in the same manner as in Production Example 1, except that gradient elution from 50% aqueous ethanol to 100% ethanol was carried out instead of the stepwise elution, and the liquid was powdered to obtain Pentacyclic Triterpene Powder 2.
(2) The obtained pentacyclic triterpene powder 2 was subjected to HPLC analysis (HPLC chart omitted), and the content of oleanane-type triterpenes was 90% by mass, the content of maslinic acid was 90% by mass, and the content of oleanolic acid was 0% by mass.

<Production Example 3: Production of marinade liquid>
0.2 parts by mass of table salt, 0.3 parts by mass of sodium glutamate, and 13.6 parts by mass of water were added to a mixer and dissolved, and then 0.2 parts by mass of pentacyclic triterpene powder 1 was added and mixed until homogeneous to produce a marinade (meat quality improver).

<Production Example 4: Production of fried chicken>
(1) A 250 g chunk of chicken thigh meat was cut into 10 pieces of chicken thigh meat, each about 25 g.
(2) The entire amount of the marinade obtained in Production Example 3 (14.3 parts by mass) was combined with 100 parts by mass of chicken thigh pieces and tumbled for 30 minutes (0.2 parts by mass of Pentacyclic Triterpene Powder 1 per 100 parts by mass of chicken thigh pieces). After tumbling, almost no marinade remained in the tumbler.
(3) The seasoned chicken thigh pieces were placed in a batter (Nippon Co., Ltd., Paris soy sauce) to coat the chicken thigh pieces with the batter, yielding fried chicken pieces. The weight of the batter before and after coating was measured, and it was found that each chicken thigh piece was coated with 10 g of batter.
(4) The obtained uncooked fried chicken pieces were placed in an oil bath preheated to 170°C and fried for 4 minutes, then arranged in a metal oil drainer tray so as not to overlap, and the oil was drained to obtain fried chicken pieces.

<Evaluation Example 1: Sensory evaluation of fried chicken>
The resulting fried chicken pieces were evaluated by 10 experienced panelists according to the following criteria: The fried chicken pieces (Reference Example 1) produced using a marinade liquid that did not contain the pentacyclic triterpene powder by replacing the pentacyclic triterpene powder with water was given a score of 3.

Texture (tenderness of meat)

Texture (juicy meat)

Test Example 1: Effect of Pentacyclic Triterpenes on the Texture of Fried Chicken
A marinade was prepared according to Production Example 3, except that the pentacyclic triterpene powder was used in the parts by mass shown in Table 1, and fried chicken was produced according to Production Example 4 and evaluated according to Evaluation Example 1. SD stands for standard deviation. In preparing the marinade, the pentacyclic triterpene powder was added as an external blend to the total amount of ingredients other than the pentacyclic triterpene powder.
As a result, in Example 1, which used 0.008 parts by mass of olive-derived oleanane triterpene (pentacyclic triterpene) per 100 parts by mass of chicken thigh meat, meat tenderness and juiciness were slightly improved, and both improved depending on the amount of olive-derived oleanane triterpene used. Similarly, in Examples 6 and 7, in which the olive-derived oleanane triterpene was the only maslinic acid used, meat tenderness and juiciness also improved with increasing amount. Example 4, in which the olive-derived oleanane triterpene consisted of maslinic acid and oleanolic acid, and Example 6, in which the olive-derived oleanane triterpene consisted of maslinic acid, were evaluated to be equivalent in terms of meat tenderness and juiciness, demonstrating that the texture of fried chicken can be improved if the marinade contains an oleanane triterpene.

Table 1

5TT stands for pentacyclic triterpene.
OTT is an abbreviation for oleanane-type triterpene.
*: Tumbling amount (parts by mass) per 100 parts by mass of chicken thigh pieces.

<Test Example 2: Investigation of tumbling treatment time>
Fried chicken was produced according to Production Example 4 except for the tumbling time shown in Table 2, and evaluated according to Evaluation Example 1. The amount of marinade remaining in the tumbler was determined by removing the chicken from the tumbler after tumbling, measuring the weight of the tumbler together with the remaining marinade, and subtracting the weight of the empty tumbler.
As a result, the meat's tenderness and juiciness improved depending on the amount of marinade remaining in the tumbler. This indicates that the texture of the meat improves depending on the amount of olive fruit-derived oleanane triterpene attached to or absorbed by the meat (chicken). The slight improvement in meat tenderness in Example 11 compared to Example 2 is due to the loosening of meat fibers caused by the impact of tumbling.

Table 2

<Production Example 5: Production of beef steak>
(1) Water was added to the marinade liquid of Production Example 3 to make the total amount 20 parts by mass, and this was used as a pickling liquid (meat quality improving agent).
(2) Australian beef lean meat was trimmed into approximately rectangular parallelepiped shapes with a thickness of 2 cm.
(3) The beef lean meat was laid out tightly on a tray, and 20 parts by mass of pickle liquid was injected per 100 parts by mass of beef lean meat.
(4) The beef lean meat injected with the pickle liquid was placed on an iron plate preheated to 220°C and grilled to medium rare to obtain beef steaks.

<Test Example 3: Effect of Pentacyclic Triterpenes on the Texture of Beef Steak>
Beef steaks were produced according to Production Example 5, except that the amounts of pentacyclic triterpene used were as shown in Table 3, and evaluated in accordance with Evaluation Example 1. When preparing the pickle solution, the pentacyclic triterpene powder was included. In the evaluation, beef steaks (Reference Example 2) injected with a pickle solution in which the pentacyclic triterpene was replaced with water were scored 3 points for tenderness and juiciness.
As a result, the tenderness and juiciness of the beef lean meat improved with an increase in the amount of oleanane-type triterpenes injected. Example 14, which contained maslinic acid and oleanolic acid but had the same oleanane-type triterpene content, and Example 15, which contained only maslinic acid, were comparable in both tenderness and juiciness.

Table 3

5TT stands for pentacyclic triterpene.
OTT is an abbreviation for oleanane-type triterpene.
*: Amount injected (parts by mass) per 100 parts by mass of lean beef.

<Production Example 6: Production of fried squid>
(1) The squid was opened, the internal organs and thin skin removed, and the water was thoroughly wiped off. A grid-like cut was made on both sides, and the squid was cut into 5 cm x 2 cm strips to obtain squid fillets.
(2) 97.5 parts by mass of soft flour, 1.5 parts by mass of powdered chicken stock, and 1 part by mass of pentacyclic triterpene powder 1 were added to a mixer and mixed until homogeneous to obtain a coating powder (meat quality improver).
(3) 100 parts by mass of squid fillets and 5 parts by mass of coating powder were placed in a plastic bag and tapped for 1 minute until the coating powder was evenly adhered to the squid fillets.
(4) The squid fillets with the coating powder attached were placed in an oil bath preheated to 170°C and fried for 2 minutes, then lined up in a metal oil drainer tray so as not to overlap, and the oil was drained to obtain fried squid.

<Test Example 4: Effect of Pentacyclic Triterpenes on the Texture of Fried Squid>
Fried squid was produced according to Production Example 6, except that the pentacyclic triterpene powder shown in Table 4 was used, and evaluated in accordance with Evaluation Example 1. In producing the coating powder, the pentacyclic triterpene powder was substituted for soft flour. In the evaluation, the softness and juiciness of the fried squid meat using coating powder that did not contain pentacyclic triterpene (Reference Example 3) were scored as 3 points.
As a result, the tenderness and juiciness of the squid meat improved with increasing amounts of olive fruit-derived oleanane triterpenes (pentacyclic triterpenes). The improvement was comparable to that of the fried chicken in Test Example 1 and the beef steak in Test Example 3.

Table 4

5TT stands for pentacyclic triterpene.
OTT is an abbreviation for oleanane-type triterpene.
*: Content (parts by mass) per 100 parts by mass of dusting powder.
**: Amount of adhesion per 100 parts by mass of squid fillets (content per 5 parts by mass of dusting powder, unit: parts by mass).

Test Example 5: Effect of Pentacyclic Triterpenes on the Texture of Various Fried Foods
Beef fillets, duck fillets, filleted horse mackerel, scallops, and vannamei shrimp were used as fried ingredients to produce fried foods in the same manner as in Test Example 4. As with the squid fillets, the tenderness and juiciness of the meat improved with an increase in the amount of olive fruit-derived oleanane-type triterpene (pentacyclic triterpene) attached to each of the fried foods.

<Production Example 7: Production of Pentacyclic Triterpene Powder 3>
(1) Apple skins were peeled from apples and placed in a tabletop mixer to obtain pulverized apple skins.
(2) Pentacyclic triterpene powder 3 was obtained in accordance with Production Example 2, except that pulverized apple peel was used as the starting material.
(3) The obtained pentacyclic triterpene powder 3 was subjected to HPLC analysis (HPLC chart omitted), and the content of ursane-type triterpenes was found to be 90% by mass, and the content of ursolic acid was found to be 90% by mass.

Test Example 6: Effect of ursane-type triterpenes on the texture of fried chicken
A marinade was prepared according to Production Example 3, except that the pentacyclic triterpene powder was used in the amounts shown in Table 5, and fried chicken was produced according to Production Example 4 and evaluated according to Evaluation Example 1. The results are shown in Table 5. Examples 2 and 3 are repeated.
As a result, even when ursolic acid, an ursane-type triterpene, was used, the meat became softer and juicier depending on the amount used, and the texture improvement effect was almost the same as in Examples 2 and 3, which used oleanane-type triterpenes.

Table 5

5TT stands for pentacyclic triterpene.
*: Tumbling amount (parts by mass) per 100 parts by mass of chicken thigh pieces.

From the above results, although it will take some time to clarify the mechanism by which pentacyclic triterpenes exert their meat quality improving effect, it is believed that the meat quality improving effect is brought about by the amphipathic properties of the lipophilic pentacyclic triterpene skeleton and the hydrophilic functional groups, such as hydroxyl and carboxyl groups, attached to the skeleton, combined with the properties of the pentacyclic triterpene skeleton itself. Since pentacyclic triterpenes generally possess hydrophilic groups, such as hydroxyl and carboxyl groups, it is inferred that the meat quality improving effect shown in this test example is possessed by all pentacyclic triterpenes.

Claims (7)

A meat quality improver containing a plant extract containing a pentacyclic triterpene , wherein the plant extract is a lower alcohol or a hydrous lower alcohol extract, and contains 10% by mass or more of the pentacyclic triterpene relative to the total amount of the meat quality improver . The meat quality improving agent according to claim 1, wherein the plant extract containing a pentacyclic triterpene is selected from the group consisting of olive fruit extract, almond pit extract, and apple peel extract. The meat quality improver according to claim 1 or 2, wherein the pentacyclic triterpene is one or more selected from the group consisting of oleanane-type triterpenes, ursane-type triterpenes, lupane-type triterpenes, and hopane-type triterpenes. A method for improving the quality of meat, comprising the step of treating meat with the meat quality improving agent according to any one of claims 1 to 3. The method for improving meat quality according to claim 4, wherein the amount of pentacyclic triterpene used is 0.001 to 20 parts by mass per 100 parts by mass of meat. A method for producing processed meat foods, comprising the steps of treating meat with the meat quality improving agent according to any one of claims 1 to 3 and heating the treated meat. The method for producing a processed meat food product according to claim 6, wherein the amount of pentacyclic triterpene used is 0.001 to 20 parts by mass per 100 parts by mass of meat.