JP5646211B2 - Pet food - Google Patents

Description

  The present invention relates to a pet food containing an unsaturated fatty acid-containing fat.

  Due to the pet boom, the number of pets is increasing, and with it, diseases similar to human adult diseases such as pet obesity, diabetes and liver disease are increasing due to aging of pets, lack of exercise, overnutrition and the like. In addition, dogs and cats who become obese due to hormonal imbalance after contraceptive surgery are increasing. Many pet foods for preventing such obesity and weight gain have been developed. For example, pet foods containing fats and oils with a high unsaturated fatty acid content have been proposed.

  Such pet foods contain a large amount of unsaturated fatty acids, so that they are easily oxidized depending on the storage environment, and may affect odor, palatability and the like. In view of this, the present applicant, in a pet food with a high mineral content, includes a technology for blending vitamin C derivatives (Patent Document 1), a naturally occurring antioxidant, and the content of iron ions and copper ions in the pet food. It has been proposed to improve long-term storage stability by controlling technology (Patent Document 2).

  Moreover, as an antioxidant system for food applications, a combination of a glyceride having a medium chain fatty acid as a constituent fatty acid and an antioxidant (Patent Document 3), a bayberry extract, a water-soluble antioxidant and a lipophilic antioxidant A combination (Patent Document 4), a combination of a mushroom mycelium culture filtrate and the like and an antioxidant (Patent Document 5) has been proposed.

JP 2005-204659 A JP 2007-110916 A JP 2004-115758 A JP 2007-185138 A Japanese Patent Laid-Open No. 7-59548

  In recent years, as the health-consciousness of pets has increased, fats and oils composed of fatty acids having many unsaturated bonds in the molecule, such as ω3 fatty acids and ω6 fatty acids that are expected to have various physiological effects, have been developed. There is a need for pet foods that contain a large amount. However, these fatty acids are very easy to oxidize and it is difficult to express a physiological effect over a long period of time. Accordingly, there is a demand for achieving long-term storage stability in pet foods containing oils and fats containing such highly unsaturated fatty acids as constituent fatty acids.

Therefore, the present inventors have examined the long-term storage stability of pet foods containing fats and oils containing unsaturated fatty acids having two or more double bonds as constituent fatty acids. It has been proved that the addition of a simple metal salt, particularly copper or iron, promotes the oxidation of the oil and fat, and a stable pet food containing both cannot be obtained. Therefore, various studies were conducted to improve its oxidative stability. As a result, catechin, vitamin E, lecithin, vitamin C, carotene, etc., which are considered to have an anti-oxidant effect, contained unsaturated fatty acid-containing fats and metals. It was found that the oxidation of the salt-containing pet food could not be sufficiently prevented, but the oxidation could be remarkably prevented by adding citric acid or a salt thereof in a predetermined amount or more.
As a result of studying to further improve the stabilizing action of pet food by the citric acid or its salt formulation, the present inventor unexpectedly found a rosemary extract that hardly has an antioxidant action when added alone. The present inventors have found that the stability of a pet food containing an unsaturated fatty acid-containing oil and metal salt and a metal salt can be remarkably improved if blended with a predetermined amount or more of citric acid or a salt thereof, and the present invention has been completed.

That is, this invention provides the pet food containing the following component (A)-(D).
(A) an oil or fat containing an unsaturated fatty acid having two or more double bonds as a constituent fatty acid,
(B) Mineral component selected from iron, iron compound, copper and copper compound,
(C) Citric acid and / or salt thereof The total amount is 10 times or more by molar ratio with respect to component (B),
(D) Rosemary extract

  In addition, the present invention includes (A) an oil and fat containing an unsaturated fatty acid having two or more double bonds as a constituent fatty acid, and (B) a mineral component selected from iron, an iron compound, copper, and a copper compound. (C) Citric acid and / or a salt thereof, and (D) rosemary extract are blended with the product, and a method for preventing oxidation of the composition is provided.

  The pet food of the present invention is remarkably excellent in long-term storage stability. Therefore, when blended with fats and oils containing a large amount of highly unsaturated fatty acids such as ω3 and ω6 as constituent fatty acids, the expected physiological function can be expressed over a long period of time. Moreover, the change of the smell accompanying the oxidation of a fatty acid, the fall of palatability, etc. can be suppressed effectively.

It is a figure which shows the result of having evaluated the antioxidant power of the various antioxidant with respect to the composition containing fats and oils and a mineral component by the rancimat test method. It is a figure which shows the time-dependent change of the electrical conductivity of a sample. It is a figure which shows the influence which the mixing | blending of a rosemary extract has on a rancimat rise time in addition to a citric acid and / or its salt.

The pet food of the present invention contains (A) an oil and fat containing an unsaturated fatty acid having two or more double bonds (hereinafter also simply referred to as a highly unsaturated fatty acid) as a constituent fatty acid. The content of polyunsaturated fatty acids in the constituent fatty acids of the fats and oils is 20 to 90% by mass (hereinafter simply referred to as%), further 23 to 80%, particularly 25 to 25% from the viewpoint of the health of pet skin and hair. 70% is preferable. Moreover, 2-45% of the content in the pet food of the fats and oils containing a highly unsaturated fatty acid as a constituent fatty acid is preferable, 2.5-40% is more preferable, 3-35% is further more preferable. Here, as a highly unsaturated fatty acid, a C18-24 highly unsaturated fatty acid is mentioned as a suitable thing. An example of an unsaturated fatty acid having two double bonds is linoleic acid. Moreover, it is preferable from the viewpoint which can expect many physiological effects to contain many unsaturated fatty acids which have three or more double bonds. As the unsaturated fatty acid, α-linolenic acid, γ-linolenic acid, arachidonic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) are preferable, and the content of the fatty acid in the constituent fatty acid of the component (A) Is preferably 3.0% or more, more preferably 3.5% or more, and even more preferably 4.0% or more.
In addition, as a fatty acid which comprises the fats and oils of a component (A), you may contain the unsaturated fatty acid and saturated fatty acid which have one double bond other than a highly unsaturated fatty acid. Here, examples of the unsaturated fatty acid having one double bond include unsaturated fatty acids having 16 to 24 carbon atoms, and oleic acid, palmitooleic acid and the like are preferable. Moreover, as a saturated fatty acid, a C12-C18 saturated fatty acid is mentioned, A palmitic acid, a stearic acid, etc. are suitable.

  In this invention, you may contain fats and oils which do not contain fats and oils other than a component (A), ie, a highly unsaturated fatty acid, as a constituent fatty acid. The content of the total fats and oils in the pet food of the present invention is preferably 6 to 50%, more preferably 6 to 45%, further preferably 6 to 40%, from the viewpoints of palatability and removal of unpleasant odor of the pet food. -35% is particularly preferred.

  As the oils and fats used in the pet food of the present invention, safflower oil, olive oil, cottonseed oil, corn oil, rapeseed oil, soybean oil, palm oil, sunflower oil, linseed oil containing the above highly unsaturated fatty acids as constituent fatty acids, Sesame oil, lard, beef tallow, fish oil, milk fat, coconut oil, coconut oil, rice bran oil, shiso oil, sesame oil, evening primrose oil, hemp seed oil and the like. Among these, linseed oil, fish oil, shiso oil, sesame oil, evening primrose oil, and hemp seed oil containing many unsaturated fatty acids having three or more double bonds as constituent fatty acids are preferable. However, it is not restricted to what was mix | blended as fats and oils, and when this is contained in other plant raw materials or animal raw materials, this is also included. Moreover, diglyceride may be contained in the fats and oils.

The pet food of the present invention also contains a mineral component selected from iron, an iron compound, copper and a copper compound as the component (B).
Examples of the iron compound include iron sulfate, ferric chloride, ferrous fumarate, ferrous carbonate, and iron oxide. The content of the iron compound in the pet food is within an acceptable range in pet food blending, 0.00001 to 1% in terms of iron, 0.00005 to 0.3%, particularly 0.0001 to 0.1%. Is preferred.

  Examples of the copper compound include copper sulfate, copper chloride, copper oxide, copper carbonate, copper sulfide, copper chlorophyll and the like. The content of the copper compound in the pet food is within an acceptable range in the pet food formulation, 0.00001 to 0.1% in terms of copper, 0.00005 to 0.03%, particularly 0.0001 to 0.00. 01% is preferred.

  Of these mineral components, iron or an iron compound and copper or a copper compound are preferably used in combination. In the present invention, the total content of these mineral components is preferably 0.0005 to 1%, more preferably 0.0005 to 0.5% in terms of mineral (in terms of iron and copper), and 0.001 to 0.001. 0.1% is more preferable.

  The pet food of the present invention may contain manganese, cobalt, calcium, phosphorus, sodium, potassium and the like as a mineral component in addition to iron and copper. These mineral components are blended as, for example, manganese oxide, cobalt carbonate, calcium carbonate, calcium phosphate, sodium chloride, potassium chloride and the like.

  The pet food of the present invention further contains citric acid and / or a salt thereof as component (C), and the total amount thereof is 10 times or more in molar ratio with respect to component (B). Here, examples of the citrate include alkali metal salts and alkaline earth metal salts, and alkali metal salts are particularly preferable. The alkali metal salt means a normal salt of citric acid (trialkali metal salt), a monohydrogen dialkali metal salt, and a dihydrogen alkali metal salt. Examples of the alkali metal salt of citric acid include sodium salt and potassium salt, and sodium salt is particularly preferable. In the present specification, unless otherwise specified, sodium citrate represents trisodium citrate (dihydrate).

  When the total amount of citric acid and its salt is 10 times or more in molar ratio to the metal of component (B), the antioxidant effect by the combined use of citric acid and / or its salt and rosemary extract is synergistic. (See FIG. 3). As shown in FIG. 3, even when the same molar ratio is less than 10 times (2 to 8 times in the figure), an increasing tendency of the antioxidant effect can be seen, but the increase is dependent on the amount of rosemary extract added. Variations are likely to occur. In the present invention, the molar ratio is set to 10 times or more from the viewpoint of stably increasing the antioxidant effect. The total amount of the component (C) is more preferably 11 times or more and particularly preferably 12 times or more in terms of a molar ratio to the component (B). Further, the total amount of citric acid or a salt thereof is preferably 60 times or less in terms of molar ratio with respect to component (B) from the viewpoint of palatability.

Moreover, it is preferable that 0.2% or more of component (C) is contained in pet food in conversion of citric acid. Here, “in terms of citric acid” means that when component (C) contains citric acid and an alkali metal salt of citric acid (hereinafter also referred to as citric acid), or component (C) is an alkali of citric acid. When it is only a metal salt, it means that the alkali metal content is replaced with hydrogen, and the mass is converted with the molecular weight of citric acid.
The pet food of the present invention preferably contains citric acids in an amount of 0.5% or more, further 0.7% or more, particularly 1.0% or more in terms of citric acid from the viewpoint of storage stability and palatability. . The upper limit of the citric acid content is preferably 5.0%, particularly 4.0% in consideration of palatability and odor during storage.

  In the pet food of this invention, a rosemary extract is contained as a component (D) with a component (C). As in the present invention, the rosemary extract has a low effect when used alone in a blended system of fats and oils containing a highly unsaturated fatty acid as a constituent fatty acid and a mineral component. It does not reach the oxidizing power (see FIG. 1). On the other hand, in a system containing 1.0% citric acid alone, the antioxidant power is restored to the level of a system not containing a mineral component. In the present invention, by allowing a predetermined amount of citric acid and rosemary extract to coexist with the oil and fat of component (A), the antioxidant power is improved to a level that cannot be imagined from the effects of each. It is what I found. In fact, when δ-tocopherol, which is another commonly known antioxidant, was coexistent with citric acid, a phenomenon was observed in which the antioxidant power was lower than citric acid alone (FIG. 1). . In other words, this improvement in antioxidant power can be said to be a unique phenomenon by combining citric acid and rosemary extract.

  The rosemary extract used in the present invention is a water and / or organic solvent extract of the leaves of rosemary, which is a plant of the family Lamiaceae, and has a unique aroma that is generally an herb. More specifically, it can be obtained by drying, pulverizing, and extracting rosemary leaves with water, hot water, hexane, ethanol, acetone, ethyl acetate, or a mixed solvent thereof. In the present invention, in addition to the above-mentioned extract with water and / or an organic solvent, oleoresin formulations formulated with the same or formulations such as rosmanol, carsonol, isorosmalol, which are constituents, may be used. Those obtained by deodorizing these extracts by a depressurization method, a heating depressurization method, a supercritical extraction method, a column adsorption method or the like (hereinafter referred to as a deodorized product) are particularly preferred in terms of flavor. Here, as a commercially available product of rosemary extract, Harbor Rocks Type O, Type HT-O, Type 25, Duolite NMH, NM-1 (above, manufactured by Calsec Co., Ltd.), Leomile E, Leomile IO ( As mentioned above, Lion Corp.) RM Keeper (above, manufactured by Mitsubishi Chemical Foods) and the like can be mentioned.

Component (D) is contained in an amount of 0.04% or more based on the fat of component (A) from the viewpoint of the antioxidant effect. From a higher antioxidant effect, flavor and economical viewpoint, it is preferably 0.04% or more and 0.4% or less, particularly preferably 0.08% or more and 0.2% or less.
Moreover, it is preferable to contain a component (D) 0.004% or more in the pet food whole quantity of this invention from a viewpoint of an antioxidant effect and flavor, 0.008% or more, especially 0.01% or more.

  The pet food of the present invention preferably has a pH of 3.5 to 7.0. Within this range, oxidation of the component (A) by the component (B) is more effectively suppressed, and the palatability is also improved. It is preferable that the pH is 4.0 to 7.0, more preferably 4.5 to 6.8, since the effect of suppressing oxidation is further enhanced and the odor during storage is improved. In order to include citric acids and make the pH within such a range, there is a method of adding a pH adjusting agent in addition to citric acid. Among such methods, a method using citric acid and citrate in combination is preferable because it is easy to adjust the pH, has good palatability, and has a uniform taste. In particular, it is preferable to use the above-mentioned alkali metal citrate as the citrate.

In addition, "pH of pet food" means pH when pet food is measured by the following method.
<Method for measuring pH of pet food>
Qualitative filter paper (10 g of pet food) was added to 60 mL of ion exchange water at 45 ° C. (preferably ion exchange water having an electric conductivity of 0.01 mS / m or less at 25 ° C.) and allowed to stand for 1 hour. No. 1, manufactured by Advantec) and the pH of the filtrate was measured at 25 ° C.
In addition, when the property of pet food is solid, it is preferable to perform the said stirring operation after grind | pulverizing finely using a mortar etc.

  The pet food of the present invention preferably further contains a carbohydrate. Examples of the carbohydrate source include monosaccharides, oligosaccharides, polysaccharides, dietary fibers, and starches. Starches include waxy corn starch, corn starch, wheat starch, rice starch, glutinous rice starch, potato starch, honeydew starch, tapioca starch, sago starch, or those that have been chemically treated or chemically modified. Can be mentioned. Carbohydrates may be contained as cereals, and examples of cereals include corn, wheat, rye, sorghum, rice, fin, awa, amarasansus, quinoa and the like. Carbohydrates are contained in pet food in an amount of 10 to 70%, further 20 to 60%, especially 30 to 50%, so that the health, the anti-obesity effect, intake, stool condition, and appearance are healthy and beautiful. It is preferable from the point.

In the pet food of the present invention, it is preferable that animal or plant protein is further included from the viewpoint of preventing obesity, ingestion, nutritional balance, and the appearance of healthy, beautiful animals. Sex proteins are particularly preferred. Examples of animal protein include milk protein such as casein, but animal meat protein is preferable from the viewpoint of obesity prevention effect and ingestion. Such animal meat proteins include cattle, pigs, sheep, rabbits, kangaroos and other meats and beef, and by-products and processed products thereof; chicken, turkey, quail and other meats and by-products and houses. Articles: Fish meat such as fish and white fish, and by-products and processed products thereof; lettering of the above raw materials such as meat meal, meat bones, chicken meal, portary meal, fish meal, and the like. Among these, chicken and fish are particularly preferable from the viewpoint of preventing obesity. In the case of using a mixture of a plurality of meat proteins, it is preferable to contain 30 to 100%, particularly 50 to 100%, of chicken and / or fish meat in the meat.
As the vegetable protein, soybean protein, wheat protein, wheat gluten, corn gluten and the like are preferable.

  In the pet food of the present invention, the animal or vegetable protein is preferably contained in an amount of 5 to 70%, more preferably 10 to 60%, and particularly preferably 15 to 40% in terms of loss on drying.

  The pet food of the present invention may further contain a plant sterol. The plant sterol is preferably contained in the pet food in an amount of 0.1% or more, more preferably 0.5% or more from the viewpoint of cholesterol lowering effect. Moreover, the upper limit of plant sterol content should just be the range of 0.1 to 30%. Examples of plant sterols include free forms such as α-sitosterol, β-sitosterol, stigmasterol, campesterol, α-sitostanol, β-sitostanol, stigmasteranol, campestanol, and cycloartenol, and the like. And fatty acid esters, ferulic acid esters, cinnamic acid esters and the like.

  The pet food of the present invention can further contain bran, potatoes, vegetables, vitamins, other antioxidants, and the like. As rice bran, rice bran, bran or the like is used, and as rice cake, soybean meal is used. Examples of vegetables include vegetable extracts. Examples of vitamins include A, B1, B2, D, E, niacin, pantothenic acid, carotene and the like, preferably 0.05 to 10%. In addition, a gelling agent, a shape-retaining agent, a pH adjuster, a seasoning, an antiseptic, a nutrition reinforcing agent and the like that are generally used in pet foods can also be contained.

  The pet food of the present invention can be produced by mixing the above ingredients into a desired form, but it is preferable to add the fat component of component (A) last. For example, citric acid and citrate are mixed together with grains, meat meal, and mineral components such as iron and copper, and after sufficient mixing, they are extruded by an extruder while being hydrated with water or steam. Thereafter, it is preferably dried with hot air until the water content becomes 10% or less. It is desirable to coat fats and oils whose double bonds are rich in two or more fatty acids after drying with hot air.

  In addition, the pet food of the present invention may be in any form such as dry type, wet type, semi-moist type, jerky type, biscuit type, gum type, granular, powdery, soup, etc. Is preferable from the viewpoint of easy storage. Usually, in the case of a dry type, a plurality of times of pet food is contained in a laminate package. However, after opening, the environment is easy to come into contact with air, so that oxidation tends to proceed. Therefore, it can be said that the pet food of the present invention is more effective in the dry type.

Examples of dry-type pet foods include kibble shapes, flat plate shapes, and bone shapes. From the viewpoint of pet chewability and shape, the bulk density is preferably 100 to 900 kg / m ³ , particularly 300 to 700 kg / m ³ . However, with such a bulk density, the surface area is increased and a large number of voids are likely to be present on the surface, so it can be said that the oxidation of fats and oils in pet food is likely to proceed. However, even in such a case, since the pet food of the present invention has a high antioxidant power, it is possible to take advantage of the advantages described above. For this reason, it is excellent in the palatability of a pet, a flavor etc. do not deteriorate over a long period of time, and can also receive the benefit of the desired physiological effect resulting from a highly unsaturated fatty acid.

<Preparation of sample>
(A) Oil and fat shown in Table 1, (B) Mineral component, (C) Citric acid + Sodium citrate (mass ratio 1: 2; hereinafter referred to as citric acid mixture), (D) Rosemary extract, (X) Various combinations of other antioxidants were tested. In the test, (A) 3 g of fats and oils were blended with (D) rosemary extract and (X) other antioxidants, and (B) mineral components and (C) citric acid / citrate were dissolved in a small amount of water. Things were added.

Details of the materials used in the test are shown below.
(A) Fat and oil The fatty acid composition is as shown in Table 2.
(B) Mineral component Ferric chloride: Reagent, Wako Pure Chemicals Cupric chloride: Reagent, Wako Pure Chemicals (C) Citric acid mixture Sodium citrate (dihydrate): Reagents, Wako Pure Chemicals Quen Acid (anhydrous): Reagent, Wako Pure Chemicals (D) Rosemary extract Product name Harbalox HT-OC (Rosemary extract content 40%) Product made by Kalsec Inc RM Keeper (Rosemary extract content 20% (Mitsubishi Chemical Foods, Inc. (X) Other antioxidants Catechin preparations: Product name Polyphenon Mitsui Norin Co., Ltd.)
(Tea extract: 30% content)
δ-tocopherol: manufactured by Tama Seikagaku Co., Ltd. mix-tocopherol: manufactured by Archer Daniels Midland Company

<Method for evaluating antioxidants>
The prepared sample is attached to an automatic oil and fat stability test apparatus (“Rancimat 743”, manufactured by Metrohm), kept at 120 ° C. while bubbling air under the condition of 20 mL / min, and the electrical conductivity is measured. The electric conductivity with respect to time is plotted, the rise time (unit: time) is obtained as shown in FIG. 2, and the stability is evaluated. This is an evaluation based on the principle that electrical conductivity increases due to oxidation, and a long rise time means high resistance to oxidation.

<How to read Rancimat rise time>
The effect of the antioxidant was determined based on whether the rise time was extended as compared with the composition before adding the antioxidant. In addition, from the experience so far, it is considered that the fat and oil used in the pet food preferably has a rise time of rancimat (hereinafter referred to as a rise time) exceeding 3 hours, so this was evaluated as a preferable composition. Moreover, the graph produced based on a part of these results is shown in FIG.

<Material that further enhances the effect of citric acid mixture>
Test Nos. 12, 17, 20, and 22 are systems in which fats and oils, minerals, and citric acid are blended, respectively, and show the results of adding 1.0% by mass of the respective fats and oils in the form of antioxidants. In contrast to Test No. 4, an effect of further enhancing the effect of the citric acid mixture was observed only in the rosemary extract.

Rosemary extract is generally more expensive and has a unique aroma compared to citric acid mixtures. Therefore, it is necessary to adjust the amount of the citric acid mixture in order to obtain the maximum effect with the minimum addition amount. In test numbers 5-9 and 11, the concentration of the citric acid mixture was examined, and the results are shown in FIG. It was found that the antioxidant effect when the rosemary extract was added can be stably and maximized by adding the citric acid mixture more than 10 moles of the mineral.
In addition, when the concentration of the rosemary extract is changed at 10 mol times or more of the mineral in the citric acid mixture, the addition of 0.04% exceeds the stability of the citric acid mixture alone, and the addition of the rosemary extract The effect was confirmed. Moreover, sufficient oxidation stability (rise time more than 3 hours) as a pet food was shown by adding 0.08% or more.

<Evaluation of antioxidant power in pet food>
A cylindrical pet food (kibble) having a diameter of 10 mm and a length of about 10 mm was manufactured by adding the components shown in Table 6 using the raw materials having the composition shown in Table 4 and mixing extrusion molding with an extruder. . The bulk density was 472 g / m ² .

  Tables 5 to 7 show the glyceride or fatty acid composition of fats and oils extracted from the pet food of Reference Example and the unsaturated fatty acid content having two and three or more double bonds.

  The total fat and oil contained in pet food is 15%, the content of unsaturated fatty acids with 2 or more double bonds in pet food is 28.2%, and the content of unsaturated fatty acids with 3 or more double bonds Was 7.45%.

<Evaluation method of odor of fats and oils>
It was stored at room temperature (about 20 ° C.) for 4 weeks, and the change in the odor of fats and oils was evaluated by sensory evaluation by 5 humans. The number of people who answered “I hardly feel a deodorized odor” was expressed as “4 or more”, “2 to 3” as Δ, and “1 or less” as “X”.

<Stability test method>
It preserve | saved at room temperature (about 20 degreeC), took out in the 0th week and the 4th week, respectively, and measured POV (peroxide number) of the fats and oils to contain. Table 4 shows the POV increase during this period.

<Measurement method of POV (peroxide value)>
The peroxide value (POV) was analyzed in accordance with 2.4.12.2-94 “Peroxide Value” of “Standard Oil and Fat Analytical Test Method” established by the Japan Oil and Fat Chemical Society.
(1) Extraction of fats and oils from pet food 50 g of kibble was pulverized, passed through a 1 mm sieve, the sample was filled into a cylindrical filter paper, and set in an open column with a cock. With the cock closed, 150 mL of diethyl ether was dropped from above with a dropping funnel, and after completion of dropping, the column cock was opened to collect diethyl ether. Next, the same operation was performed with 50 mL diethyl ether. The recovered diethyl ether was removed by an evaporator to obtain an extracted fat from pet food.

(2) POV measurement of fats and oils 0.5 g of fats and oils extracted from pet food were weighed into a 250 ml tall beaker, and 20 ml of a solution of acetic acid / isooctane = 3/2 (volume ratio) was dissolved. 0.1 mL of saturated potassium iodide solution was added to the tall beaker and shaken well for 1 minute. Thereafter, 30 mL of distilled water was added to obtain a titration sample. The titration sample was titrated with 0.01N sodium thiosulfate. At this time, a POV automatic titrator, DMP Titorino 785 type, manufactured by Metrohm Shibata Co., Ltd. was used.

(3) Evaluation of antioxidant effect Table 4 shows that the POV increase value (4 weeks) of fats and oils is 10 or less, ◯ is over 10 and 15 or less, Δ is over 15 and x is over. In addition, POV in the case of no addition was about 35.

<Method of measuring citric acid equivalent value>
Add 5 mL of 5% perchloric acid to kibble (3.0 g) crushed with a mixer and shake for 10 minutes. After shaking, the volume is adjusted with a 50 mL volumetric flask. Ultrasonic treatment is performed for 10 minutes, and measurement is performed by a high performance liquid chromatograph (HPLC) method using the filtered solution. The HPLC measurement conditions are as follows.
Column: 2 Shodex Rspak KC-811, diameter 8mm x length 300mm (made by Showa Denko KK)
Column temperature: 40 ° C
Mobile phase: 3 mmol / L perchloric acid aqueous solution Reaction solution: 0.2 mmol / L bromothymol blue-containing 15 mmol / L disodium hydrogen phosphate aqueous solution Flow rate: mobile phase 1.0 mL / min, reaction solution 1.4 mL / min Measurement wavelength : 445 nm

  As shown in Table 4, the pet food of the example showed high oxidative stability after storage for 4 weeks.

Claims (7)

A pet food containing the following components (A) to (D).
(A) Oils and fats containing unsaturated fatty acids containing two or more double bonds as constituent fatty acids,
(B) Mineral component selected from iron, iron compound, copper and copper compound,
(C) Citric acid and / or salt thereof The total amount is 10 times or more of component (B) in molar ratio,
(D) Rosemary extract Content is 0.08% or more and 0.4% or less with respect to a component (A) .   The pet food according to claim 1, wherein the salt of citric acid is an alkali metal citrate.   The pet food according to claim 1 or 2, wherein the component (C) contains both citric acid and a salt of citric acid.   The pet food according to any one of claims 1 to 3, wherein the component (A) is an oil containing 3% by mass or more of a ω3 or ω6 unsaturated fatty acid as a constituent unsaturated fatty acid.   The pet food according to any one of claims 1 to 4, which has a pH of 3.5 to 7.0.   The pet food according to any one of claims 1 to 5, which is a dry type. (A) A composition containing an oil containing an unsaturated fatty acid containing two or more double bonds as a constituent fatty acid, and (B) a mineral component selected from iron, an iron compound, copper and a copper compound. Citric acid and / or a salt thereof as a total amount is blended in a molar ratio of 10 times or more of component (B) , and (D) rosemary extract is 0.08% or more with respect to component (A) 0 A method for preventing oxidation of the composition, characterized by comprising 4% or less .

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