RU2388320C2 - Method of extending storage life of food compounds containing polyunsaturated fatty acids - Google Patents

Abstract

FIELD: food industry.

SUBSTANCE: method involves mixing food base with at least one long chain polyunsaturated fatty acid, thermal treatment of the resultant mixture at a temperature no less than 50°C to produce a food compound, adding to the food compound a second amount of at least one long chain polyunsaturated fatty acid protected against oxidation and packaging the resultant mixture in a low oxygen environment to produce a food product. The amount of long chain polyunsaturated fatty acids jointly ensures bioefficient amount of long chain polyunsaturated fatty acid(s). The product storage life is at least 6 months. The packaged dry food product contains a compound that contains a food base and a bioefficient amount of at least one long chain polyunsaturated fatty acid in a low oxygen environment in a sealed container.

EFFECT: invention enables production of a stable food compound containing long chain polyunsaturated fatty acids whose storage life is at least 6 months.

33 cl, 5 tbl, 10 ex

Description

Description

The application has priority application US Ser. No. 60/722780 of September 30, 2005, incorporated herein by reference.

The invention relates to methods for increasing the shelf life of food compositions, in particular to methods for increasing the shelf life of food compositions containing one or more long chain polyunsaturated fatty acids.

Some long chain polyunsaturated fatty acids (LCPUFAs) are essential nutrients for animal health. The increasing popularity of LCPUFA is associated with their beneficial health effects when included in animals. Since these essential nutrients cannot be synthesized from the main substrates of most living organisms, at least in quantities sufficient to reveal the full spectrum of beneficial properties of such nutrients, LCPUFA or their precursors must be present in animal food. Typically, LCPUFAs are present in low amounts in the food of many animals, including the human diet, but they are completely absent in many types of food.

Omega-3 fatty acids, such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are the most important LCPUFAs in animal food. As important structural components of the central nervous system, they are the most important dietary components for pregnant animals and newborns. It is believed that such LCPUFAs enhance cognitive function, especially when consumed in the early stages of development. It was found that both EPA and DHA increase the density of the tubular bones, reduce the risk of cancer, reduce inflammatory reactions, and also increase visual acuity and retinal function in infants. Both acids play a role in preventing asthma and allergic reactions, as well as in alleviating the symptoms of psoriasis and arthritis. There are reports of cardiovascular activity of EPA and DHA, including improved heart rate in patients with coronary heart disease, a prolonged decrease in blood levels of LDL (low density lipoprotein) and a decrease in the incidence of sudden death in patients with coronary heart disease.

Especially large amounts of EPA and DHA are found in marine animal fat. High concentrations of such omega-3 fatty acids are found in the fat of fish living in cold waters, such as salmon, mackerel, menhaden, sardines, halibut, cod, trout, tuna, eel, herring and other varieties. Other sources of EPA and DHA include seal fat, dolphin oil, whale oil, polar bear fat, plankton, krill, algae, and microbial sources.

Given the healing properties of such substances, it is desirable to incorporate LCPUFA, in particular EPA and DHA, into food compositions. However, the considered fatty acids undergo rapid oxidation when exposed to air, metals, light and / or heat during storage of such compositions. The oxidation of LCPUFA lowers the nutritional and palatability of food compositions and increases the cost of production. In addition, compositions containing LCPUFA oxidation products may adversely affect the health and immunity of an animal consuming such substances.

Flax and linseed oil are popular sources of LCPUFA and have slightly higher oxidation stability than other sources of LCPUFA. However, flax and linseed oil are not direct sources of EPA and DHA. Flax and linseed oil contain the precursor LCPUFA, which can be metabolized in the body to form EPA and DHA.

In US Patent No. 6063414 describes dry food with a high content of soluble fiber, which has increased palatability when packaging in gas-tight bags, and not in paper bags. It is stated that the food contains flaxseed flour and is characterized by "several times higher content of unsaturated fatty acids that are oxidized than traditional animal feed." The results of studies of water activity, but not palatability of the feed when changing the atmosphere inside the bag, for example, as a result of a nitrogen purge to reduce the oxygen content to less than 2% and / or with the addition of oxygen scavengers, are presented.

In US Patent No. 6063414 describes a dry food with a high content of soluble fibers with increased palatability when packaging in gas-tight bags, and not in laminated or non-laminated paper bags. It is stated that the food contains flaxseed flour and is characterized by "several times higher content of unsaturated fatty acids that are oxidized than traditional animal feed." The results of studies of the effect of water, but not of the palatability of the feed when the atmosphere inside the bag changes, for example, as a result of a nitrogen purge to reduce the oxygen content to less than 2% and / or with the addition of oxygen absorbers, are presented.

Lytle et al. (1992) in Nutrition and Cancer 17 (2), 187-194 describe low temperature (<40 ° C) preparation of rodent food in the form of a powder or granules containing 16% fish oil. It is reported that the formulations are packaged in thermo-glued bags purged with nitrogen. Analysis of the content of fatty acids in granules dried in air, granules dried in vacuum, dried powder feed, granules after staying in air for four days at ambient temperature and granules after storage for 45 days at -20 ° C did not allow to establish statically significant differences in the composition of fatty acids.

Analytical data from short-term studies do not necessarily indicate the long shelf life of a food composition containing one or more LCPUFAs. Therefore, there is still a need to develop a method for stabilizing a food composition containing LCPUFA, in particular food compositions containing EPA and DHA, providing a shelf life of at least 6 months.

The invention relates to a method for producing a food product, in which:

(a) the feed base is mixed with from zero to a first amount of at least one LCPUFA;

(b) the resulting mixture is boiled at a temperature of not less than about 50 ° C to obtain a food composition;

(c) zero to a second amount of at least one oxidation protected LCPUFA is added to the food composition; and

(d) the resulting composition is packaged in a medium with a low oxygen content in an airtight container to obtain a food product;

moreover, the first and second quantities of LCPUFA, each of which, but not both, may be zero, indicated in stages (a) and (c), together provide a bioeffective amount of LCPUFA; the packaged composition is characterized by acceptable palatability for the animals to which it is proposed; the food product has a shelf life of at least 6 months when stored at ambient temperature without opening the container, and the shelf life is determined (i) by the significant conservation of the bioeffective amount of at least one LCPUFA and (ii) the significant retention of the palatability of the composition after removing from the container.

The invention provides a food product using the method described above. In addition, the invention relates to a dry food product, including a sealed container, the atmosphere of which is depleted of oxygen, in which there is a composition containing a nutritional base and a bioeffective amount of at least one LCPUFA, the food composition having an acceptable palatability for the animal to which it proposed; the food product is characterized by a shelf life of at least about 6 months when stored at ambient temperature without opening the container; otherwise, the shelf life is determined (i) by the significant conservation of the bioeffective amount of at least one LCPUFA and (ii) by significant storage the palatability of the composition after it is removed from the container.

Other objectives, features and advantages of the invention will also be apparent to those skilled in the art, as well as other fields of application of the invention, from the following detailed description.

The term “long chain polyunsaturated fatty acids” or “LCPUFA” refers to a fatty acid that is usually part of a triglyceride with a carbon chain containing at least 18, typically 18-22 carbon atoms and at least 2 olefinic double bonds.

LCPUFA includes omega-6 and omega-3 fatty acids. In omega-6 fatty acid, the first double bond is between 6 and 7 carbon atoms, counting from the terminal methyl group of the carbon chain. Examples of omega-6 fatty acids are linoleic acid (18: 2n-6), γ-linolenic acid, sometimes referred to as GLA (18: 3n-6), and arachidonic acid (20: 4n-6). In omega-3 fatty acid, the first double bond is between 3 and 4 carbon atoms, counting from the terminal methyl group of the carbon chain. Examples of omega-3 fatty acids include α-linolenic acid or ALA (18: 3n-3), eicosapentaenoic acid or EPA (20: 5n-3), and docosahexaenoic acid or DHA (22: 6n-3).

In step (a) of the method, the scheme of which is given above, the food base is mixed with from zero to a first amount of at least one LCPUFA.

The term "food base" means a composition containing one or more food ingredients and capable of providing at least part of the animal's daily needs for protein and energy sources such as carbohydrates and lipids. Typically, but not necessarily, the nutritional base also provides at least a portion of the animal's daily needs for essential amino acids, vitamins and minerals. according to one embodiment of the invention, the nutritional base comprises starch / protein / fat complex. In another embodiment, the food base is suitable for preparing a treat. According to another embodiment, the nutritional base almost completely meets the animal’s protein and energy needs.

Any feed benefits from the inclusion of at least one LCPUFA. In one embodiment, the invention provides a composition in which a food base comprises a major (at least 25%, e.g., 50% by weight) component, derived from animal protein tissues (e.g., mammals, birds, fish or seafood), including muscle tissue and / or tripe, optionally in admixture with a carbohydrate source, such as cereal granules.

In step (a), the nutritional base is mixed with at least one LCPUFA. At least one LCPUFA may be used in crude, semi-purified, purified or synthetic form, as a natural oil enriched in at least one LCPUFA, or a food ingredient containing such oil. Typically, at least one LCPUFA is present as a triglyceride component, but if necessary, at least a portion of it may be present as a free acid. Oils enriched with LCPUFA and food ingredients containing such oils are well known to those skilled in the art and are further described below.

Mixing LCPUFA (or the oil or food ingredient containing it) with the nutritional base can be carried out in any known manner, and the consistency of the resulting mixture can vary from very coarse to very fine. So, for example, the coarse mixture may contain separate pockets with LCPUFA-containing oil or food ingredient inside the matrix of the nutrient base. The thin mixture may contain at least one LCPUFA more or less uniformly distributed in the matrix.

Typically, but without specific limitations of the invention, food compositions are prepared by an extrusion process, in which, after initial mixing or compounding of the food ingredients to form a dry mixture, hydration and heat treatment are carried out in a device referred to as a pre-treatment cylinder or “pre-conditioner” "From which the hydrated and at least partially welded mixture enters the extruder. The preconditioner and extruder may be parts of the same device. according to one embodiment of the invention, at least one LCPUFA is administered in the form of a matrix formed from a starch / protein / fat complex in a nutritional basis; such administration can be carried out in a preconditioner, for example, by injecting a composition, such as an oil, containing at least one LCPUFA. During the extrusion cooking of cereals and protein mixtures, moistened granular flour materials turn into dough. The starch components are gelled, which leads to a significant absorption of moisture and an increase in the viscosity of the dough. Protein components affect the elasticity characteristic of hydrated ripened adhesive text. Fats are introduced into the matrix. At low moisture contents (<20%) and high temperatures, the formation of lipid / amylase and lipid / protein complexes is very likely. As shown by chemical analysis, LCPUFA is part of such a matrix.

The term “mixing a nutritional base with at least one LCPUFA” does not limit the order in which particular ingredients are administered. So, for example, it is not necessary to mix all the ingredients of the nutrient base first and then administer at least one LCPUFA. If necessary, some nutrient base ingredients may be administered after the addition of at least one LCPUFA. At least one LCPUFA may be added in one or more of the steps of step (a) described above, for example, as components of one or more oils or food ingredients. In the case of a composition obtained by extrusion, one part of the LCPUFA can be introduced into the preconditioner and the other part into the extruder.

As noted above, in step (a), “from zero to first amount” of at least one LCPUFA is used. In one embodiment, virtually no LCPUFA is added at this stage of the process. According to another embodiment, the “first amount” of at least one LCPUFA together with the “second amount” added in step (c) form a total bioeffective amount of at least one LCPUFA. In yet another embodiment, the “first amount” of at least one LCPUFA added in step (a) constitutes substantially all of the bioeffective amount of LCPUFA introduced into the process. The foregoing defines what is meant by a “bioeffective amount” of at least one LCPUFA.

In step (b) of the above method, the mixture from step (a) is subjected to heat treatment at a temperature of not less than about 50 ° C to obtain a food composition.

It should be borne in mind that steps (a) and (b) do not have to be carried out sequentially. As indicated above, steps (a) and (b) can be carried out simultaneously, for example, in a pre-conditioner. However, step (a) should not be carried out after completion of step (b); The LCPUFA added after step (b) is processed under the conditions described below for step (c). In steps (a) and (b), at least one LCPUFA added in step (a) is subjected to high temperature treatment as a component of the mixture, which is heat treated in step (c).

Any known heat treatment method can be used to increase the temperature of the mixture by at least about 50 ° C, including, without specific restrictions, boiling, frying, roasting, steaming, baking, grilling and the like in any suitable cooking device. According to various embodiments of the invention, the mixture is heated to a temperature of not less than about 65 ° C, not less than about 80 ° C, or not less than about 95 ° C. The pre-treatment takes about 2 minutes. The residence time of the composition in the extruder is from 5 to 10 seconds. The preferred maximum temperature is about 110 ° C.

In one embodiment, cooking is carried out, at least in part, by injection of steam, for example superheated steam, into a dry mixture. In this case, hydration is carried out, and cooking of the mixture begins, which, as described above, can be carried out in the pre-conditioner.

In the case of food compositions prepared by extrusion, cooking can continue in the extruder, which moves the composition, now in the form of a hot plastic mass, through an appropriately perforated matrix disk. The composition in the form of threads emerging from the holes of the matrix can be cut into pieces of the desired length, for example, using a rotating knife device.

If the food composition is to be packaged in a wet or semi-moist form, it is in a state of readiness, optionally after cooling, for processing in step (c). However, according to one embodiment of the invention, the heat-treated and hydrated food composition is dried to obtain a dry food. The term "dry food" is used in the conventional sense, implying that the food contains 3-11% of water. Dry food prepared by extruding and cutting the resulting yarns into short pieces is known as granular food. Drying is usually carried out at elevated temperatures and additional heat treatment may occur at this stage.

Without specific theoretical limitations, it is contemplated that the presence of a thin boundary layer of water, such as an aqueous monolayer on the surfaces of dry food, such as granular food, can limit the contact of the food composition with atmospheric oxygen. In one embodiment, the feed water content should not be so low as to prevent the formation of the boundary layer. So, for example, the water content of dry food obtained by the described method can be 6-11%, for example 7-10%.

In step (c) of the process described above, from zero to a second amount of at least one oxidation protected LCPUFA is added to the food composition obtained in the heat treatment step. Such an addition can be made before or after drying (in the case of a dry food product), when the composition is still in a hot state, or after cooling.

According to one of the options at this stage of the process, LCPUFA is practically not added. In another embodiment, a “second amount” of at least one LCPUFA, together with a “first amount” added in step (a), form a total bioeffective amount of at least one LCPUFA. In yet another embodiment, the “second amount” of at least one LCPUFA added in step (c) constitutes substantially all of the bioeffective amount of LCPUFA introduced into the process.

LCPUFA may be added in any form as described above for step (a). However, when added in step (c), at least one LCPUFA must be “protected from oxidation”, i.e. placed in an environment that significantly limits the possibility of reaction with oxygen or strong oxidizing agents such as peroxides.

One of the following examples can illustrate the oxidative protection of at least one LCPUFA added in step (c):

(i) providing a short interval between the addition of at least one LCPUFA in step (c) and packaging in an oxygen depleted atmosphere as described below for step (d) to minimize or eliminate oxidation;

(ii) source selection of LCPUFA with low peroxide number (PV);

(iii) sealing at least one LCPUFA (for example, sealing a natural oil containing at least one LCPUFA) by encapsulating the capsule shell as an oxygen barrier; and / or

(iv) adding one or more antioxidants in conjunction with at least one LCPUFA.

The interval “short enough” to minimize or eliminate oxidation may depend on various factors, including the nature of the LCPUFA source and its fatty acid content, the temperature of the food composition to which LCPUFA is added, etc., and can be determined without additional experiments. but usually its duration should not exceed 24 hours.

PV is a criterion for the presence of hydroperoxides that initiate the autooxidation of unsaturated fatty acids. According to one embodiment of the invention, the PV value of the LCPUFA source used in the method of the invention should not be more than about 5 meq / kg, preferably for most purposes, not more than about 2 meq / kg.

Sealing involves microencapsulation. Microcapsules of any suitable size, for example, from about 100 to about 1500 microns, preferably from about 500 to about 900 microns, can be used. Microcapsules can be obtained by any known method, for example, crosslinking with glutaraldehyde. Microencapsulation makes it possible to obtain materials containing marine animal oil in the form of a dry powder.

Without specific limitations, suitable antioxidants include butylated hydroxyanisole (BHA), butylated hydroxytoluene (BHT), rosemary extracts, ethoxyquinone, ascorbic acid, tocopherols, tocotrienes, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid ( for example, Trolox ^R ), their salts and esters, as well as combinations of these substances. Many patented antioxidant preparations contain rosemary extracts in some cases, together with other antioxidants. These drugs include Duralox ™ and Naturox ™.

In the case where an unsaturated fatty acid loses a hydrogen atom, a free radical is formed in the position of unsaturation. The free radical quickly turns into a peroxide free radical of a fatty acid and then into a fatty acid hydroperoxide. Hydroperoxides can decompose to form aldehydes and ketones, which create a rancid taste and reduce palatability, and can also create other less serious side effects. Such a reaction can be anticipated if, after the formation of the primary free radical, a hydrogen atom is introduced to replace hydrogen lost by fatty acid. The antioxidants listed above primarily provide the replacement of the hydrogen atom, necessary to prevent the peroxidation of free radicals of fatty acids.

The selection of the antioxidant system can be carried out by a specialist using any known method. One such method, known as the Oxidation Stability Index (OSI) method, is an automated method for determining the time taken to form oxidation products in a heated oil. If the OSI value is less than about 15 hours, this means that the selected antioxidant system is not active enough. In one embodiment, an antioxidant system with an OSI value of at least about 30 hours is selected.

The addition of at least one LCPUFA to the food composition in step (c) is usually a local operation, i.e. involves applying the added material to the surface. In the case where the food composition is a dry granule, the addition of at least one LCPUFA may be combined with the addition of other materials commonly used in coatings, for example, flavoring agents such as fats, animal extracts and flavorings.

In step (d) of the above method, the food composition is packaged in an oxygen depleted atmosphere in an airtight container to obtain a food product.

The “oxygen depleted environment” inside the container is a medium with a significantly lower partial oxygen pressure (pO ₂ ) than the environment (about 160 Torr). Thus, for example, pO ₂ in a container may have a value of less than about 80, less than about 50, less than about 30, or less than about 15 Torr. Reduced pO ₂ can be created using vacuum; on the other hand, the container or free space (the empty volume of the container above the food composition) may be purged with an inert gas such as nitrogen or a noble gas to form an oxygen depleted atmosphere. So, for example, a nitrogen purge can easily reduce the oxygen content in the atmosphere of the container to about 5% or less, for example to about 2% or less.

Standard canning methods in which the can is sealed when the wet components are heated and the empty space contains mostly water vapor also lead to an oxygen depleted environment, as water vapor condenses when cooled, creating a low vacuum.

To ensure a long shelf life, the oxygen-depleted environment must be maintained during the long-term storage of the food product, for example for at least about 6 months. Accordingly, the walls of the container should be made of a material that impedes the transport of oxygen, or at least should be lined with a layer of such material. Suitable materials for this purpose include metal (e.g. steel or aluminum), glass, and low oxygen permeability polymers such as high density polyethylene (HDPE), EVOH, film foil, metallized film, and high density polyethylene laminated film. It is also important that the container is well sealed. For a dry food product, it is usually sufficient to use standard multilayer packaging, for example paper bags with a protective layer of HDPE or laminated with metallized plastic. in one embodiment, a multilayer package is used having an inner layer or lining containing an oxygen scavenger or antioxidant.

As noted above, the first and second amounts (any of which, but not both, may be zero) indicated in steps (a) and (c) respectively provide a generally bioeffective amount of LCPUFA. The term “bioeffective amount” refers to an amount that, when consumed daily, provides good overall nutrition and improves animal health.

LCPUFAs are involved in a variety of life functions. However, the bioeffective amount of LCPUFA depends on the nature of the LCPUFA, the type of animal, the duration of feeding, and the particular aspect of the animal’s health. For example, a dietary content of only about 0.02% dry matter (DM) is effective for overall improvement in the quality of life of older dogs when feeding for a long time, while at least about 2.5 % DM may be necessary to mitigate soft tissue damage during irradiation, and at least 5% DM must be used to inhibit oncogenesis in cancer patients. The use of at least about 0.05% DM is effective for enhancing the cognitive function of dogs, at least about 0.1% DM for alleviating diarrhea, at least about 0.2% DM for improving joint activity at least about 0.2% to improve the hunting characteristics of dogs and at least about 0.5% DM to influence behavior. The maximum amount of LCPUFA in an animal’s diet is the maximum amount tolerated by an animal without manifesting negative side effects.

In the case where the food composition is a treat used in a relatively small amount to supplement the diet with one or more LCPUFAs, it is desirable to use higher concentrations of LCPUFAs than in a composition that satisfies almost all the nutritional needs of the animal.

According to various embodiments of the invention, the total amount of LCPUFA in the food product obtained by the method according to the invention can be from 0.02% DM to a maximum amount, for example from about 0.05 to about 50%, from about 0.1 to about 20% or from about 0.2 to about 10%. Similar quantitative ranges apply to any particular LCPUFA or combination of LCPUFA, for example, linoleic acid, EPA, DHA, or a mixture thereof.

In the event that at least one LCPUFA is localized, for example, in the pockets of the inside of the granules or on the surface of the granules, local concentrations may exceed the suggested values, however, the total amount in the feed will be in the above ranges.

In one embodiment, at least one LCPUFA contains EPA, DHA, or mixtures thereof. In another embodiment, at least one LCPUFA is linoleic acid. According to another embodiment of the invention, the at least one LCPUFA comprises linoleic acid, as well as at least one acid selected from EPA and DHA. So, for example, linoleic acid, contained, for example, in linseed oil, can be added in step (a), and a mixture of EPA and DHA, contained, for example, in marine animal fat, can be added in step (c).

As indicated above, at least one LCPUFA may be added as a natural oil enriched in LCPUFA. Some vegetable oils, especially oils derived from the seeds, nuts, grains and beans of certain plants, are rich sources of LCPUFA. Examples of such substances are linseed oil, rapeseed oil (including canola oil), and walnut oil (especially enriched with ALA); corn, cottonseed, safflower, soybean and sunflower oil (containing a large amount of linoleic acid); as well as blackcurrant, borage and evening primrose oil (containing a large amount of GLA). A variety of oils derived from seafood, commonly referred to as “ocean oils,” are also rich sources of LCPUFA. An example of such substances is fish oil, obtained from fish living in cold waters, such as salmon, mackerel, menhaden, sardines, halibut, cod, trout, tuna, eel and herring, which is especially rich in EPA and DHA. Oils fortified with LCPUFA can be extracted from raw sources, but in many cases sources such as flaxseed oil can be used directly.

As noted above, the packaged composition is palatable to the animal to which it is offered. The term “palatability” refers to the case when an animal prefers one food over another, which should be established using the type test protocol, according to which the animal has equal access to both food compositions. This preference may be the result of any sensation experienced by the animal, but usually the taste and aroma are the basis for the preference. The test food obtained according to the invention and characterized by “acceptable palatability” is a product that is not particularly preferred over a standard food selected from the most popular food of the same type, for example, granular food, canned food, treats , etc. adapted for similar animals. The absence of a “strong preference” for test food is considered established if, according to the protocol, the animal consumes more than twice the amount of reference food compared to the consumption of test food (ie, the preference for the consumption of reference food does not exceed 2: 1).

As indicated above, the food product obtained by the method according to the invention must have a shelf life of at least about 6 months when stored at ambient temperature without opening the container, and the shelf life is determined (i) by the significant preservation of the bioeffective amount according to at least one LCPUFA and (ii) significantly preserving the palatability of the composition after it is removed from the container.

If significant oxidation of at least one LCPUFA occurs during storage, the bioefficiency may decrease and the palatability of the product may be impaired, for example, due to the accumulation of oxidation products. The method described above provides such a limitation of the oxidation process that leads to an unexpected increase in the shelf life, which is judged by the preservation of bioefficiency and palatability. In some embodiments, the shelf life is at least 9 months, at least 1 year, or at least 2 years.

The term "shelf life" refers to storage without opening (or other depressurization) of the container at ambient temperature. The term "ambient temperature" refers to any temperature in the traditional range for the interior of a warehouse or retail space, for example 15-25 ° C. It should be borne in mind that storage at a higher temperature can reduce the shelf life, and at lower temperatures, increase it.

Bioeffectiveness can be determined directly by in vivo testing of animals for which the composition is nutritionally and / or organoleptically adapted, or in laboratory animals representing an adequate nutritional and metabolic model of the animal species in question; bioefficiency testing can also be carried out using a model system, such as an invertebrate model, non-animal model, cell culture or ex vivo model using tissue explants. In one embodiment, bioefficiency is determined indirectly by chemical analysis of the food composition after storage, and the total LCPUFA content or the content of one or more individual LCPUFAs is measured. Various indicators of LCPUFA content are known to those skilled in the art, including a polyene index (measurement of the LCPUFA content which uses saturated C ₁₆ fatty acid, hexadecanoic acid as a standard).

Other criteria can be used to determine the shelf life, for example, an acceptable low level of oxidation products of at least one LCPUFA.

The following is an example of a method for producing a wet food product. The crushed protein tissues of animals (e.g., mammals, poultry, fish and / or seafood) are mixed with other ingredients, including, for example, animal fats and vegetable oils, cereals, other nutritionally balanced ingredients, and specialty supplements (e.g., vitamin and mineral mixtures, inorganic salts, cellulose and beet chips, fillers, etc.). Among these ingredients, there is one or more sources of at least one LCPUFA. Water is added in an amount necessary for processing. Typically, the ingredients are mixed in a vessel suitable for heating the components while mixing them. The mixture may be heated by any suitable method, for example by direct injection of steam or by using a vessel equipped with a heat exchanger. After adding the last ingredient, the mixture is heated in the pre-treatment stage to a temperature of about 100 ° C. Higher temperatures may be used, but their use is not economically viable without the use of other processing aids. Material heated to the appropriate temperature usually takes the form of a thick liquid. The thick liquid is poured into a suitable container, for example, in cans, wide-necked vessels, bags, tubes, etc. The oxygen-depleted atmosphere in each of these containers is ensured by applying a vacuum or flushing with an inert gas, followed by sealing the container. After that, the closed container is placed in a traditional device for sterilizing the contents. Typically, this operation is carried out by heating to a temperature of at least 110 ° C for an appropriate time, which depends on the temperature used and the composition of the feed. Products can also be prepared aseptically in which the contents are heated to a state of commercial sterility before being packaged in sterilized containers with an oxygen depleted atmosphere.

An example of the preparation of a wet food product is the following method. Dry ingredients, including animal protein sources, vegetable protein sources, grains, and the like, are ground and mixed together to form a dry mixture. Wet or liquid ingredients are added, including fats, oils, animal protein sources, minerals, water and the like, and the resulting system is mixed. Among the listed ingredients may be one or more sources of at least one LCPUFA. The dry mixture is hydrated in the preconditioner by steam injection, whereby the cooking of the composition begins. The hydrated composition is fed to an extruder in which the cooked or semi-cooked mixture is extruded and cut into granules using a rotating knife. After that, the granules are dried and, optionally, one or more external coatings are applied, containing, for example, perfumes, fats, oils, powders, etc., as well as a source of at least one LCPUFA. Finally, the granules are packaged in a container whose atmosphere is depleted of oxygen, for example, by flushing with an inert gas such as nitrogen, and the container is sealed.

Dry food can also be obtained from the LCPUFA-containing dough using a baking process. The dough can be placed in a mold before being treated with dry heat to form a lump product of a special shape, such as treats for cats and dogs. Product packaging in an oxygen depleted atmosphere is carried out according to the method described above.

The described method can be used to obtain a food product containing a composition that is nutritionally and / or organoleptically adapted for feeding a human or non-human animal. According to various embodiments of the invention, the food composition is adapted for feeding invertebrates, for example fish, birds, reptiles or mammals. Examples of mammals are members of the Carnivora order, which includes, but is not specifically limited to, dogs and cats. The food composition can be nutritionally and / or organoleptically adapted for feeding various animals, including wild animals, such as primates (e.g. monkeys, chimpanzees, etc.), domestic animals (e.g. dogs, cats, horses, etc.). ), farm animals (e.g. goats, sheep, pigs, cattle, etc.), laboratory animals (e.g. mice, rats, etc.), birds (e.g. poultry such as canaries, parrots etc., commercial birds such as chickens, ducks, geese, turkeys, etc.), rodents (e.g. hamsters, mo pigs, gerbils, rabbits, porcupines, ferrets, chinchillas, etc.), as well as wild, exotic and zoological animals (for example, wolves, bears, deer, etc.).

In some embodiments, the food composition is nutritionally and / or organoleptically adapted for feeding domestic animals. The term “pets” refers to an animal of any kind that a person is caring for, such as domestic animals, or any kind of domesticated animal, including dogs and cats, regardless of whether such animals are exclusively or partially kept for mutual communication. Thus, the term "domestic animals" refers to working dogs, farm cats, regulating the number of rodents, etc., as well as to domestic dogs and cats.

Another embodiment of the invention is a dry food product comprising a closed container containing, in an oxygen-depleted atmosphere inside the container, a food composition comprising a food base and a bioeffective amount of at least one LCPUFA, which composition has an acceptable palatability to the animal to which it is offered; the food product has a shelf life of at least about 6 months when stored at room temperature without opening the container, the shelf life being determined (i) by the significant retention of the bioeffective amount of at least one LCPUFA and (ii) by the significant retention of palatability food composition after extraction from the container.

A dry food product can be obtained as described above and can be modified as a result of any optional process changes to the extent that they correspond to a dry product.

The product may optionally contain information or instructions regarding animal feeding. Such media may include, for example, a document, such as a label, brochure, advertisement or advertising insert, a computer-readable digital or optical medium, such as a floppy disk or CD, an audio presentation, such as an audio film or a CD, a visual presentation on a videotape or DVD, or combinations thereof, or may link to additional information contained elsewhere on one or more pages of the website.

The invention is not limited to the described methodology, protocols and reagents, as they are subject to change. The accepted terminology is used only to describe specific embodiments of the invention and does not limit its scope. Used in the description and claims, the singular also include the plural, if this is not contrary to the context, for example, a reference to “method” includes many such methods. The words “comprising” and “including” should be understood in a broad, non-exclusive sense.

Unless otherwise indicated, all technical and scientific terms, as well as their acronyms, have the meanings known to those skilled in the art to which the invention relates. Although any composition, methods, products, and other similar or equivalent devices or materials can be used to practice the invention, the preferred compositions, methods, products, and other devices or materials are described in the text.

All cited patents, patent applications, publications, and other references or references to them are part of the invention to the extent permitted by law. A discussion of such references is provided solely to summarize the allegations made. No assumptions are made that patents, patent applications, publications or references, as well as any parts thereof, are a relevant prototype of the invention, and the applicant reserves the right to challenge the veracity and relevance of such patents, applications, publications and other links.

Examples

The invention is illustrated below by way of examples of preferred embodiments thereof, it should be borne in mind that these examples are provided for purposes of illustration only and, unless expressly agreed, do not in any way limit the scope of the invention.

Example 1

A nutritionally balanced dog feeding composition was prepared by the extrusion method described below. A dry mix containing 52% cornmeal, 13% poultry flour, 9% rice, 9% sifted soybean, 9% peanut husk, 4% flaxseed oil, 2% wheat gluten, 1% dry egg and 2% minerals, vitamins and other nutrients, prepared using standard dosing equipment, in which the desired concentrations of ingredients were measured, mixed in a batch device, crushed by passing through a standard sieve with a 4/64 inch hole size, and fed into the dispenser with loss-in weight feeder) Acrison. The dry mixture from the dispenser was supplied at the desired speed to the DDC-7 pre-treatment cylinder, in which the dry mixture was preconditioned before extrusion by supplying water and steam to increase the temperature of the dry mixture. This operation initiates the hydration and cooking of the starch components of the dry mix.

The preconditioned dry mix is transferred to the Wenger X-35 extruder, which further heat treats the dry mix using steam, water and friction to provide the desired characteristics regarding density, moisture content and ductility. The obtained bioplastic melt is forcibly passed through a matrix disk equipped with dies of the desired size and shape. After the cooked and formed extrudate leaves the spinnerets, the material expands and is cut into granules of the desired size using a rotating knife device.

The granules are then fed into a multi-stage horizontal belt dryer and dried to a desired moisture content, typically less than 11% by weight. After drying, the granules were sieved to remove fine particles. Thereafter, the sieved granules are coated in a continuous double-mixing screw conveyor using a mixture containing additional liquid and dry ingredients. The mixture used contained 35% linseed oil, 26% animal hydrolyzate, 10% animal fat and a natural flavor, and 29% seafood fat was added to the mixture in a tank equipped with a variable speed top mixer. Seafood oil (2.25%) contained 18% EPA and 12% DHA and was stabilized with an antioxidant. The topical mixture was supplied at the required speed as a single stream to the coating device and uniformly applied to the granules. The coated granules were fed into a cooling device and then packaged in sealed, nitrogen-purged bags with a low level of residual oxygen, resulting in a finished dog food product. Seafood oil was stabilized by the introduction of an antioxidant. Product packaging was carried out for 1 hour.

In the manner described above, numerous batches of food product were prepared. Samples of the finished composition were analyzed to determine the initial content of EPA and DHA, which are presented in Table 1.

Table 1
The initial content of EPA and DHA in the feed The consignment % DM EPA Dha one 0.37 0.31 2 0.34 0.29 3 0.41 0.33 four 0.50 0.34 5 0.36 0.24 6 0.41 0.27 7 0.40 0.25

Example 2

The dog food obtained according to Example 1 was tested for palatability using a two-pronged feeding protocol to confirm approval of the animals. The palatability was determined in comparison with four commercially available dog foods for 2 days using 20 dogs. Tests were carried out for two days, providing simultaneous access to equal amounts (approximately 500 g per dog) of each test composition and one of the dog feeds available in the commercial mixture. After 45 minutes, the food compositions were collected and weighed to determine the amount of each of the consumed compositions. After eating food, the dogs showed no signs of food intolerance. The results obtained are presented in Table 2. From the data presented it follows that dogs usually have a preference for the test composition compared to commercial dog food.

table 2
The results of the study of palatability The total amount of each food composition consumed per dog Test 1 Test Composition 225 g Purina dog chow 81 g Test 2 Test Composition 250 g Pedigree mealtime 156 g Test 3 Test Composition 176 g Iams chunks 109 g Test 4 Test Composition 217 g Scince diet diet canine senior 59 g

Example 3

The dog food obtained according to Example 1 was analyzed to determine the loss of EPA as a measure of stability. The feed was stored in nitrogen-purged sealed bags at 72 ° F and 65% relative humidity. As follows from the results presented in Table 3, for more than one year, there was no decrease in the EPA content in the feed product.

Table 3
Feed storage stability measured by EPA content The number of days after preparation EPA (% DM) 0 0.39 fourteen 0.36 28 0.36 56 0.37 84 0.38 112 0.36 140 0.37 168 0.39 196 0.35 224 0.38 252 0.33 280 0.36 308 0.39 336 0.34 364 0.34 392 0.36

Example 4

A nutritionally balanced dog food was prepared according to the method of Example 1 except that the marine animal fat was stabilized and combined with the dry mixture by injection into the cylinder for pre-treatment instead of adding to the coating mixture. The fat of marine animals was stabilized by the administration of 10,000 ppm of a commercial antioxidant.

Testing showed that the injection of marine animal fat into a pre-treatment device prior to extrusion prevents oxidation of the material. Such protection occurs as a result of introducing the oil into the matrix of the starch / protein / fat complex during the preconditioning of the feed composition. The fat of marine animals was stabilized by an antioxidant.

Example 5

A dog food was prepared containing 4% salmon fat in the coating, to which 500 ppm commercial antioxidant was added. The food was prepared according to a method similar to the method of Example 4, and it was packaged in a multilayer paper bag laminated with a plastic lining in order to obtain a finished dog food product.

The product was stored under forced conditions at 105 ° F and 65% relative humidity (assuming that under forced conditions the storage week corresponds to one month of shelf life). A measure of stability was the peroxide value (PV) (an indicator of oxidation, determined by the level of hydroperoxides) and the polyene index (the ratio of the total content of EPA and DHA to the amount of n-hexadecanoic acid). The criterion for the end of the shelf life was the value PV> 50 meq / kg of oil or a decrease in the polyene index by 20%. As follows from the data presented in Table 4, for 20 weeks of forced storage, the PV value increased from 6.7 to 19 mEq / kg of oil, which is significantly less than the maximum value of 50 mEq / kg of oil. Over the course of 14 weeks, there was a slight decrease in the polyene index, from 0.42 to 0.40, which corresponds to about a 5% decrease in EPA and DHA. The results show that the food in question is stable under ambient conditions for more than 12 months.

Table 4
Forced storage and polyene index of dog food for forced storage Storage time (weeks) PV (mEq / kg oil) Polyene Index The decrease in the content of polyenes,% 0 6.7 0.4213 3 6.4 Nd Nd 6 15.0 0.3918 7.0 9 10.0 0.3918 7.0 12 15.0 0.4034 4.2 fourteen 16,0 0.4000 5.1 fifteen 16,0 Nd Nd 16 17.0 Nd Nd eighteen 19.3 Nd Nd twenty 19.0 Nd Nd ND not determined

Example 6

Using a method similar to that described in Examples 1 and 4, a dog food was prepared containing 7% salmon oil, to which 5,000 ppm industrial antioxidant was added. Salmon oil was added as a coating to the outside of the granules or introduced into the feed during extrusion. In one embodiment, the oil is applied as a coating. In another embodiment, the oil was applied as a coating, injecting it during pretreatment. The resulting product was packaged by the method according to Example 5.

The PV value of both feeds increased during the first 6 weeks of forced storage, after which it decreased and stabilized. It is assumed that the initial increase in PV reflects the load during pretreatment. All PV values remain below the maximum criterion of 50 mEq / kg oil until 16 weeks after preparation. Measuring the polyene index of the feed, the surface of which is covered with salmon oil, gave conflicting results, but did not reveal a strong tendency to degradation during forced storage. The results obtained are presented in Table 5. The data obtained suggest that both feeds will be stable for at least 12 months of storage under ambient conditions.

Example 7

A nutritionally balanced animal feed was prepared in the form of a dry mixture containing 40-49% corn flour, 12% poultry flour, 8-11% rice, 8-11% soy flour, 6-8% peanut husks, 4% linseed oil , 1-2% egg powder, 1-2% wheat gluten and 2% minerals, vitamins and other nutrients. After mixing and grinding to reduce particle size, 0-10 wt.% Microencapsulated marine animal fat containing 25-60% omega-3 fatty acids was added. After that, the mixture was extruded and dried, following the procedure described in Example 1. The resulting granules were coated with 3% linseed oil, 2% animal hydrolyzate and 1% animal fat. The product was packaged following the procedure of Example 5.

Example 8

Nutrient-balanced dog food was prepared according to the procedure described in Example 7, except that the encapsulated marine animal oil was added to the coating rather than to the dry mix.

Example 9

Nutrient-balanced dog food was prepared according to the procedure described in Example 7, except that the dry encapsulated oil was added to the dry mixture after mixing and grinding in order to reduce particle size. The mixture was extruded as described in Example 1. 0-5% marine animal oil was added during extrusion. This example illustrates the addition of encapsulated marine animal oil at one stage in the process: after grinding the ingredients for extrusion. The addition of fish oil is also illustrated at two additional stages: during pretreatment and during coating. After extrusion and drying, the obtained granules were coated with 0-10% marine animal oil, 3% linseed oil, 2% animal hydrolyzate and 1% animal fat.

Example 10

A nutritionally balanced dog food was prepared according to the procedure described in Example 7, except as noted below. After mixing and grinding, in order to reduce the size, 0-10% of dry encapsulated marine animal oil containing 10-70% omega-3 fatty acids was added. 0-5% marine animal oil liquid was added to the preconditioner. After extrusion and drying, the obtained granules were coated with 0-10% marine animal oil, 3% linseed oil, 2% animal hydrolyzate and 1% animal fat.

Typical preferred embodiments of the invention are disclosed in the description and, despite the use of specific terms, they are used exclusively in a general and descriptive context and do not limit the invention, the scope of which is defined in the claims. From the foregoing, the possibility of many modifications and variations of the invention follows. Therefore, it should be borne in mind that within the scope of the attached claims, its practical implementation is possible, which differs from the specific options described.

Claims (33)

1. A method of obtaining a food product, comprising:
(a) mixing the food base with at least one long chain polyunsaturated fatty acid;
(b) heat treatment of the resulting mixture at a temperature of at least 50 ° C to obtain a food composition:
(c) adding to the food composition a second amount of at least one oxidation protected long chain polyunsaturated fatty acid; and
(d) packaging the resulting composition in an environment with a low oxygen content to obtain a food product;
wherein the amounts of long chain polyunsaturated fatty acid added in steps (a) and (c) together provide a bioeffective amount of long chain polyunsaturated fatty acid (s), the food product having a shelf life of at least 6 months. 2. The method according to claim 1, in which the shelf life is additionally determined by (iii) an acceptable low level of oxidation products of at least one long chain polyunsaturated fatty acid. 3. The method according to claim 1, in which the first of these amounts is a total amount of a long chain polyunsaturated fatty acid, comprising from about 0.1 to about 10 wt.% Of the composition on a dry matter basis. 4. The method according to claim 1, in which the first of these amounts is a total amount of long chain polyunsaturated fatty acid, comprising from about 0.2 to about 5 wt.% On a dry matter basis. 5. The method according to claim 1, in which the second of these amounts is a total amount of long chain polyunsaturated fatty acid, comprising from about 0.1 to about 10 wt.% On a dry matter basis. 6. The method according to claim 1, in which the second of these amounts is a total amount of long chain polyunsaturated fatty acid, comprising 0.2 to about 5 wt.% On a dry matter basis. 7. The method according to claim 1, in which the food composition is nutritionally and / or organoleptically adapted for feeding carnivores. 8. The method according to claim 1, in which the heat-treated food composition is nutritionally and / or organoleptically adapted for feeding dogs or cats. 9. The method according to claim 1, in which the prepared food composition is a dry animal feed. 10. The method according to claim 9, in which the feed is in the form of granules. 11. The method according to claim 10, in which the second of these quantities of at least one oxidatively protected long chain polyunsaturated fatty acid is added to the coating applied to the food granules. 12. The method according to claim 1, in which the first of these amounts of at least one long chain polyunsaturated fatty acid is added to the food base by introducing at least a portion of the first amount into the starch / protein / fat complex matrix. 13. The method according to item 12, in which the specified introduction is carried out by injection of at least part of at least one long chain polyunsaturated fatty acid into the preconditioner. 14. The method according to claim 1, in which the antioxidant protection, at least partially, is provided by encapsulating a second amount of the specified at least one long chain polyunsaturated fatty acid. 15. The method according to claim 1, wherein the antioxidant protection is at least partially provided by the addition of at least one antioxidant together with a second amount of at least one long chain polyunsaturated fatty acid. 16. The method according to clause 15, wherein said at least one antioxidant is selected from the group consisting of butylated hydroxyanisole, butylated hydroxytoluene, rosemary extracts, ethoxyquin, ascorbic acid, tocopherols, tocotrienes, 6-hydroxy-2,5, 7,8-tetramethylchroman-2-carboxylic acid, their salts, esters and mixtures. 17. The method according to claim 1, in which the first and / or second of these quantities of at least one long chain polyunsaturated fatty acid is added in a form containing at least one marine animal oil. 18. The method of claim 17, wherein the marine animal oil is fish oil. 19. The method of claim 18, wherein the fish oil is obtained from fish selected from the group consisting of salmon, mackerel, menhaden, sardines, halibut, cod, trout, tuna, eel, herring, and combinations thereof. 20. The method according to claim 1, in which at least one long chain polyunsaturated fatty acid in the first and / or second amount is an omega-3 fatty acid. 21. The method according to claim 20, in which the omega-3 fatty acid is selected from eicosapentaenoic acid, docosahexaenoic acid and mixtures thereof. 22. The method according to claim 1, in which at least one long chain polyunsaturated fatty acid in the first and / or second amount is linoleic acid. 23. The method according to item 22, in which linoleic acid is added in a form containing vegetable oil. 24. The method according to item 23, in which vegetable oil contains linseed oil. 25. The method according to claim 1, wherein the oxygen-depleted environment is provided by vacuum sealing the container. 26. The method according to claim 1, wherein the oxygen-depleted environment is an oxygen-depleted atmosphere over a heat-treated composition inside the container. 27. The method according to p. 26, in which the oxygen-depleted environment is provided by purging the container with inert gas before sealing it. 28. The method according to item 27, in which the inert gas is nitrogen. 29. The method according to claim 1, in which the container is a multilayer packaging. 30. The method according to clause 29, in which the multilayer packaging includes an inner layer comprising or bearing at least one antioxidant. 31. The food product obtained by the method according to claim 1. 32. A packaged dry food product containing a composition that contains a nutritional base and a bioeffective amount of at least one long chain polyunsaturated fatty acid in an oxygen-depleted environment in a sealed container, the composition exhibiting an acceptable taste for the animal to which it is offered for consumption; wherein said product has a shelf life of at least about 6 months when stored at ambient temperature without opening the container, wherein the shelf life is determined (i) by substantially preserving the bioeffective amount of at least one long chain polyunsaturated fatty acid and (ii ) to significantly preserve the taste of the composition after extraction from the container. 33. The food product of claim 32, further comprising means for providing information or instructions regarding feeding the animals with said composition.