ES2363957A1 - Employment of a mushroom extract in the production of foodstuffs. (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Use of an extract of madroºo in the elaboration of food products. The invention relates to a process for obtaining an extract with antioxidant properties from the arbutus (fruit of arbutus unedo l) comprising the steps: (a) extraction from the fruit crushed with a solvent selected from water, ethanol or its mixing and obtaining a supernatant (b) concentration of the supernatant resulting from step (a) by vacuum distillation. The invention also relates to said extract and to food compositions such as for example meat products containing it. (Machine-translation by Google Translate, not legally binding)

Description

Use of an extract of madroño in the Food products development.

Field of the Invention

The present invention falls within the food sector and more particularly within the sector of antioxidant additives for food in general. Specifically, the invention relates to an extract with antioxidant properties obtained from the fruit of the madroñera ( Arbutus unedo L.) and its use in the preparation of food compositions such as meat products that have improved properties in terms of their shelf life. and sensory characteristics.

Background of the invention

Synthetic antioxidants have been used for years as food additives to prolong the shelf life, especially of fats and products with a high lipid content, delaying their oxidation process. However, its use is increasingly restricted due to the potential risks and toxicity of these substances and the rejection of consumers (Nawar WW (1996). Lipids. In Food Chemistry, OR Fennema (ed.), Pp 225-319 , Marcel Dekker, Inc., New York-Basel-Hong Kong). Thus, today the trend of the food industry is focused on replacing these synthetic antioxidants with naturally occurring antioxidants, especially those from plants. A few years ago, the term antioxidant of natural origin was mainly associated with compounds such as ascorbic acid -vitamin C-, vitamin E and eventually with vitamin A. However, in recent years numerous investigations have expanded the number of species Chemicals with antioxidant activity, among which the so-called "polyphenols" stand out due to the presence in their chemical structure of one or more phenolic rings (Heinonen, M. (2007). Antioxidant activity and antimicrobial effect of berry phenolics: a Finnish perspective- Review, Mol. Nutr. Food Res ., 51, 684-691).

These phenolic compounds and in particular the present in fruits and vegetables, they have gained interest among consumers and in the scientific community because in addition to its use As antioxidants in food, numerous trials have found evidence that these compounds present, in certain conditions, antibacterial properties, as well as beneficial effects against certain pathologies cardiovascular or against certain types of cancer.

However, there are also a good number of publications and scientific trials in which the use of polyphenols as antioxidant agents did not report beneficial results or even showed themselves as pro-oxidizing agents, that is, they promote oxidation, in oxidative stability tests ( Estévez, M .; Kylli, P .; Puolanne, E .; Kivikari, R .; & Heinonen, M. (2008) Oxidation of skeletal muscle myofibrillar proteins in oil-in-water emulsions: interaction with lipids and effect of selected phenolic compounds. Journal of Agricultural and Food Chemistry , 56, 10933-10940; Salminen, H. & Heinonen, M. (2008). Plant phenolics affect oxidation of tryptophan. Journal of Agricultural and Food Chemistry, 2008, 56, 7472-81) . At present it is known that this apparent contradiction of the results obtained can be attributed to several factors that must always be taken into account when considering the use of these compounds as an antioxidant in food:

Under the term "polyphenols" a wide variety of phenolic compounds are included that are classified into: 1.-) flavonoids , formed by two aromatic rings joined by an oxygenated heterocycle, and among which are flavonols, flavones, isoflavones, anthocyanins , proanthocyanidins, flavanones, etc. and 2.-) non-flavonoids , commonly called phenolic acids, which contain an aromatic ring with different functional groups. The distribution of these compounds in plants, their polarity and solubility, as well as their antioxidant activity varies significantly among the different chemical families, so it is required a broad knowledge of what phenolic compounds and in what concentration are present in a given extract, in order to predict its potential use as an antioxidant.

In general, phenolic compounds are attributed reducing characteristics as they act as electron donor agents demonstrating their potential as free radical neutralizers, and thus acting as antioxidants. However, in more complex systems such as in a meat product, phenolic compounds are integrated into much more complex redox reactions and their reducing potential is dependent on many factors such as pH, concentration or the presence of other compounds such as metals or other antioxidants, the same compound being able to act as an antioxidant or pro-oxidant depending on the factors described above. In addition, plant phenolic compounds can also regenerate other antioxidants or act synergistically.
genetically or antagonistically with other phenolic compounds or other endogenous antioxidants such as vitamin E.

Therefore, in view of the above, it is evident that there is still a need to provide new effective natural extracts with antioxidant capacity, as well as non-pro-oxidant, in order to be used in the food sector and extend the half-life of same. In this sense the inventors have discovered a new extract obtained from the strawberry tree, fruit of the strawberry tree ( Arbutus unedo L.), useful for its use in the elaboration in general of food products, and meat products in particular. This extract has proven its effectiveness as an antioxidant agent in raw and heat treated meat products, improving their shelf life and oxidative stability, being also a product that does not produce significant changes in the color or taste of food.

Brief description of the figures

Figure 1. Evolution of the TBA-RS content of fresh hamburgers subjected to refrigeration and made with a base formula (Control) and with the addition of an extract obtained from the fruits of Arbutus unedo L.

Figure 2. Evolution of the content in TBA-RS of cooked hamburgers subjected to refrigeration and made with a base formula (Control) and with the addition of an extract obtained from the fruit Arbutus unedo L.

Figure 3. Evolution of the carbonyl content of cooked hamburgers subjected to refrigeration and made with a base formula (Control) and with the addition of an extract obtained from the Arbutus unedo L. fruit.

Figure 4. Evolution of the a * value of the CIELa * b * system of cooked hamburgers subjected to refrigeration and made with a base formula (Control) and with the addition of an extract obtained from the Arbutus unedo L. fruit.

Description of the invention

The present invention is therefore related to an extract with antioxidant activity obtained from the fruit of Arbutus unedo L. useful for its use in the preparation in general of food products, and meat products in particular.

The extract is obtainable by means of a procedure, hereinafter procedure of the invention, which It comprises the following stages:

(a) extraction from crushed fruit with a solvent selected from water, ethanol or mixtures thereof and obtaining a supernatant

(b) concentration of the supernatant resulting from step (a) by vacuum distillation.

The Arbutus unedo L. (common name madroñera; name of the madroño fruit) is a shrub of wide distribution in the Mediterranean ecosystem. The process of the invention first comprises the collection of the fruits, their washing and cutting. The cut fruits are then contacted with the selected solvent, which in a particular embodiment is a mixture of ethanol and water, preferably in the ratio of 7: 3. The relative amount of fruit and solvent can vary between wide margins depending in part on the need to obtain a more or less concentrated extract depending on the application after which it is destined. In a particular embodiment, the fruit: solvent ratio, with the solvent being a mixture of ethanol water of 7: 3, is 1: 5. The solvent is preferably for food use since the extract obtained is useful in the preparation of food products.

The type of solvent used determines the type of phenolic compounds extracted in each case and their concentration for an obvious question of polarity or affinity chemistry. However, the inventors have shown that extraction of phenolic compounds with water, or ethanol or with mixtures of both, leads to extracts with similar antioxidant capacity and efficacy contrasted, although the mixture of ethanol: water and in particular in 7: 3 ratio has been tested as the solvent it provides higher degree of extraction. The choice of type of solvent in particular amount of ethanol is largely determined for the use to which the extract of the invention is intended as expose later.

Stage a) of the procedure is carried out in a conventional homogenization system provided with blades and provided with means that keep the temperature the same or below 35 ° C, such as a cold water bath. You get a homogenized, which is usually separated then in a solid and a supernatant. Said separation can be done by any conventional procedure for example by centrifugation followed by filtration or decantation.

The supernatant resulting from step a) it is usually filtered and can then undergo next step b) or alternatively it can be stored refrigerated after filtration until the moment of carrying out said stage b).

Step b) comprises subjecting the supernatant from step a) to vacuum distillation which can be carried out in a conventional manner by means of, for example, a vacuum column or in a rotary evaporator. The supernatant is concentrated by removal of the solvent at low temperature as a result of the vacuum which allows to preserve the antioxidant activity of the extracted compounds. The type of solvent used in the process of the invention influences the time required for step b) (the higher the water content or if it is only
Water).

The process of the invention comprises a additional stage of characterization and titling of the activity antioxidant according to the determination of phenolic compounds totals carried out according to the method Folin-Ciocalteau (see Examples 1 and 2).

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The process of the invention has the advantage of being effective, fast, and inexpensive in addition to being environmentally friendly due to the type of solvents used, and allows obtaining an extract of the fruit of Arbutus unedo L. with antioxidant properties, which constitutes another aspect of the present invention, hereinafter referred to as an extract of the invention.

The extract of the present invention has proven effective as a particular antioxidant agent in raw and heat treated meat products tested (see example 4 and Figures 1 to 4). The results obtained have shown that also the extract improves the visual appearance of the products meat during storage, as a result of better color stability compared to a control lot as well as an effective inhibition against oxidative processes of lipids and / or proteins of meat products, improving the shelf life and oxidative stability thereof, all this, without the extract produces significant changes in color or Food flavor due to its incorporation into the products. Therefore an additional advantage of the extract of the invention is the ability not to alter the organoleptic, color properties, and taste of the food compositions to which the which obviously enhances its acceptance by the consumer.

Therefore in another aspect the invention is refers to a procedure for preparing a food composition comprising the addition thereto of the extract of the invention.

The addition can be carried out by Any conventional technique. The form of incorporation depends for example of the type of food composition, and in particular of type of meat product on which it is added. So in a preferred embodiment the addition is carried out by incorporation Direct extract in the composition of a meat product. In another particular embodiment the addition is carried out by direct incorporation to the surface of the meat product through spray micro spray. Typically before The micro-spray the extract is filtered with a suitable membrane filter (0.65 microns). Direct incorporation it can be done for example in the case of meat products not minced such as fresh or marinated meat packaged in atmospheres modified.

As mentioned above the election of the type of solvent, and in particular of the amount of ethanol in the case of an ethanol mixture: water, is largely determined by the type of food composition to which it will be added subsequently the extract of the invention as well as by the technique with which the addition of the extract is carried out. In general for get meat products in which water is added in the elaboration of its composition, such as: cooked sausages, or ham meat, an aqueous extract is preferably used diluted in the product formulation water itself, so that in the procedure for obtaining the extract is used preferably water. However, to obtain meat products in whose preparation no water is added in the composition, it is the use of ethanol or a mixture of ethanol: water with higher proportion of ethanol in the process of the invention thus facilitating the vacuum concentration stage. It should be noted no Although any solvent can be used in the procedure of the invention regardless of application concrete and the way of it. Possible variations in grade of extraction of bioactive compounds depending on the use of a greater or lesser proportion of water: ethanol are minimized by the additional step of the process of the invention of characterization and titration of the antioxidant activity in which the extracts obtained are adjusted until the concentration in antioxidant polyphenols required in each case. Similarly, other parameters, such as intrinsic variability in the composition of wild fruits (caused by harvest year, location, soil type, maturation state ...) do also that this stage of characterization and titling of the antioxidant activity should be carried out prior to its Use in food products.

In a further aspect the invention is refers to a food composition comprising the extract of the invention. Said food composition can be any type of food, food ingredient, or drink, without any limitation, such as, for example, sauces, food precooked, soups, milk, yogurt, cheeses, bread, biscuits, cookies, etc. In a particular embodiment said composition is meat product, such as for example a raw meat product, a heat treated meat product, a raw meat product Cured, a marinated meat product, among others.

The right amount of extract for each food composition and in particular for each meat product, it can vary within wide margins, and be determined in each easily case by the expert in the field. That amount depends especially of the nature of the food composition, and in particular of the meat product to which it is intended, specifically the composition, technological treatment, content and type of fat present therein, etc., In a preferred embodiment the extract is present in the food composition, and in particular in a meat product, in an amount characterized by be able to inhibit the oxidative processes of lipids and / or proteins In a particular embodiment the amount of extract in a meat product is such that the total polyphenol content which is 200-400 mg equivalent of gallic acid per kg of meat product, having been determined said content of the phenolic compounds according to the method Folin-Ciocalteau (see Example 1).

The inventors have carried out comparative tests that show the antioxidant efficacy of the extract of the invention incorporated into meat products (see Example 4). Thus, figures 1 and 2 show the results of the evolution of the TBA-RS content of fresh and cooked hamburgers subjected to refrigeration. The determination of the content in TBA-RS (thiobarbituric acid reactive substances) is one of the most widespread methods for the study of lipid oxidation in food (Raharjo, S. & Sofos, JN (1993). Methodology for measuring malonaldehyde as a product of lipid peroxidation in muscles tissues: a review. Meat Science , 35: 145-169; Estévez, M., Morcuende, D. & Ventanas, S. (2009). Determination of oxidation. In "Handbook of Muscle Foods Analysis "13, 221-239. CRC Press. Taylor & Francis Groups). This determination was made following the method described by Tarladgis et al. (1960). The rationale for this method is that malondialdehyde (a product resulting from lipid oxidation) reacts with thiobarbituric acid in an acidic medium resulting in a colored pigment that is spectrophotometrically measurable at 532 nm; therefore an increase in the content in TBA-RS is related to an increase in the development of oxidative processes of food lipids.

Figure 3 shows the results of the evolution of the carbonyl content of cooked hamburgers under refrigeration. The increase of carbonyls is a measure that indicates the development of oxidative processes of food proteins. The measurement of carbonyl content is one of the most widely used and widespread methods for determining the oxidation of meat and meat products (Estévez, M., Morcuende, D. & Ventanas, S. (2009). Determination of oxidation. In "Handbook of Muscle Foods Analysis" 13, 221-239. CRC Press. Taylor & Francis Groups). This determination of the carbonyl content shown in this example of the test of the antioxidant activity of the extract of Arbutus unedo L. was carried out according to the method described by Oliver et al. (Oliver, CN; Ahn, B.-W-; Moerman, EJ; Goldstein, S .; & Stadtman, ER (1997) Aged-related changes in oxidized proteins, J. Biol. Chem ., 262, 5488) whose basis it consists in that the carbonyls (products resulting from the oxidation of the proteins) react with the DNPH reagent (2,4-dinitrophenylhydrazine) producing a spectrophotometrically measurable pigment proportional to its concentration.

Figure 4 shows the evolution of the a * value of the CIELa * b * system of cooked hamburgers under refrigeration. Instrumental color measurement is widespread in the study of the visual characteristics of meat and meat products (Faustman, C. & Cassen, RG (1990). The biochemical basis for discoloration in fresh meat: A review. Journal of Muscle Food , 1: 217-243). In this test, the instrumental color of the hamburgers was determined by a Minolta colorimeter model Chroma Meter CR-300 equipped with diffuse xenon lamp illumination and with a measuring area of 8 mm. A D65 illuminant with observation geometry with an angle of 0 ° was used. The device was calibrated using a white calibration plate model CR-A43. The measurements were made in the CIEL * a * b * (CIE, 1976) color space from which the chromaticity coordinates L * (luminosity), a * (red-green axis) and b * (yellow-blue axis) are obtained . The results in Figure 4 show the evolution of the a * value (range -60, pure green; +60, pure red) of the CIELa * b * system, which is a measure that mainly indicates the evolution of the red color of food, this fact being of special interest in meat products. The reduction of the red coloration of meat and meat products during refrigeration is related to the oxidation of pigments present in meat (myoglobin).

Finally an additional advantage of the present invention resides in that the extract is obtained from the fruit of a bush with wide distribution and accessibility in the ecosystem Mediterranean.

Below are examples illustrative of the invention set forth for a better understanding of the invention and in no case should be considered a Limitation of its scope.

Examples Example 1 1.- In vitro characterization of the antioxidant potential of the fruits of Arbutus unedo L. as well as its functional components by means of techniques for determining total phenolic compounds

The antioxidant potential of the fruits was characterized by techniques that quantify the total phenolic compound content and antioxidant activity in vitro :

1.1. Determination of total polyphenols

The determination of phenolic compounds in the extracts of the fruit of Arbutus unedo L. was carried out by the Folin-Ciocalteu method described by Singleton and Rossi (Singleton, VL, & Rossi, JA (1965). Colorimetry of total phenolics with phosphomolybdic-phosphotungstic acid reagents Am. J. Enol. Vitic ., 144-158) with modifications Pantelidis et al. (Pantelidis, GE, Vasilakakis, M., Manganaris, GA, & Diamantidis, Gr. (2007). Antioxidant capacity, phenol, anthocyanin and ascorbic acid contents in raspberries, blackberries, red currants, gooseberries and Cornelian cherries. Food Chemistry , 102 , 777-783). The results are shown in Table 1. The rationale for this determination is based on the phenolic compounds of the fruits oxidized by the Folin-Ciocalteu reagent, giving a blue coloration directly proportional to the polyphenol content. Briefly, a 0.5 mL aliquot of the ethanol extract was taken in a test tube; subsequently 2.5 mL of 10% Folin-Ciocalteu reagent (in water) and 2.0 mL of 7.5% sodium carbonate (w / v) were added. The mixture was incubated at room temperature in the dark for 60 minutes. After this period of time the absorbency was measured immediately at 740 nm, against a blank in which the sample was replaced by the same amount of water. Quantitative measurements were performed by contrasting the results with a calibration curve using gallic acid as standard. The results were expressed as mg of gallic acid equivalents (GAE) / 100 g of fruit.

1.2 Tests of antioxidant activity in vitro using radical scavenging techniques

The determination of the in vitro antioxidant activity of the fruits was carried out by testing with the radical, 2,2-diphenyl-1-picrylhydrazyl -DPPH- and with the determination of the equivalent antioxidant capacity of TROLOX (TEAC) using the radical ABTS. These techniques are based on the ability of substances with antioxidant activity to reduce a synthetic radical that has a spectrophotometrically measurable coloration, its in vitro antioxidant activity being proportional to the discoloration produced to the radical.

1.2.1 Determination of antioxidant activity by method radical-2,2-diphenyl-1-picrylhydrazyl (DPPH)

The antioxidant activity of the ethanolic extract of the arbutus was determined by the DPPH radical technique described by Turkmen et al. (Turkmen, N., Sari, F., & Velioglu, YS (2006). Effects of extraction solvents on concentration and antioxidant activity of black and mate tea polyphenols determined by ferrous tartrate and Folin-Ciocalteu methods. Food Chemistry , 99, 835-841); The results are shown in Table 1. A solution of 6 x 10-5M DPPH in methanol was prepared. This intense violet solution has a maximum absorption at 517 nm. Solutions with increasing concentrations of the ethanolic extract of Arbutus unedo L. were prepared. Thus, an aliquot of each of the solutions was mixed with 1,950 mL of the DPPH radical in methanol. The mixture was allowed to incubate at room temperature and in the dark for 90 minutes. The absorbance of the violet solution of the DPPH radical was measured at 517 nm against a methanol blank (Initial DPPH Absorbance) presenting values close to 0.700. To calculate the percentage of DPPH radical inhibition for each extract concentration, the following equation was used:

% inhibition = [(Initial DPPH Abs - Remaining DPPH Abs) / DPPH Abs initial] * 100

The antioxidant capacity of each sample was expressed as the amount of sample (concentration of antioxidant) necessary to decrease the initial concentration of 50% DPPH (EC50). To calculate this parameter it is necessary develop a standard curve for each fruit extract where face increasing concentrations of the antioxidant (extract of fruit) with the percentage inhibition of the radical obtained for said concentration

1.2.2. Determination of antioxidant capacity Trolox equivalent (TEAC) using ABTS radical

The analysis of the equivalent antioxidant capacity of Trolox (TEAC) of the extract of the fruit of Arbutus unedo L. was performed using the method of the radical 2,2'-azinobis- (3-ethylbenzothiazoline-6-sulfonic acid) -ABTS- according to the method described by Re et al. (Re R., Pellegrini, N., Proteggente, A., Pannala, A., Yang, M., & Rice-Evans, C. (1999). Antioxidant activity applying an improved ABTS radical cation decolorization assay. Free Radical Biol Med ., 26, 1231-1237).

First, the ABTS + cation radical was generated in vitro by reacting equal amounts (5 mL) of 7 mM ABTS (in water) and 2.45 mM of potassium persulfate (in water). The mixture was then incubated at room temperature and in the dark for 15 hours (a dark navy solution is obtained). This solution was subsequently diluted with ethanol until the absorbance reached (initial ABTS + Abs).

One milliliter of the diluted ABTS + solution (initial absorbance: 0.700 at 734 nm) was mixed with 10 µL of a diluted extract (1:10) of the Arbutus unedo L. fruit. The reaction mixture was incubated in the dark at room temperature for 6 minutes The absorbances of the ABTS + radical solution and of the test samples (fruit extracts + ABTS +) were measured immediately at 734 nm, against an ethanol blank. It was calculated as a percentage of inhibition according to the following formula:

% inhibition = [(Abs ABTS + initial - Abs ABTS + remaining) / Abs ABTS + initial] * 100

The percentages of inhibition obtained for the problem samples are extrapolated in the calibration curve which allows us to present the results as TEAC (Trolox equivalent antioxidant activity) that is, antioxidant activity equivalent to that of Trolox (mM Trolox / milligram extract fresh fruit).

TABLE 1 Total phenolic compounds (CFT) content and antioxidant activity against DPPH and ABTS radicals of the ethanol extract from the fruit of Arbutus unedo L

one

1.3 Determination of the profile of phenolic compounds by HPLC

Once the in vitro antioxidant capacity of the extract was tested, the profile of phenolic compounds was determined by HPLC in order to know the main compounds to determine their potential use.

For this, an analysis was performed according to the methods described by Kähkönen et al. (Kähkönen, M., Hopia, A. & Heinonen, M. 2001. Berry Phenolics and Their Antioxidant Activity. Journal of Agricultural and Food Chemistry . 49: 4076-4082) and Kylli et al (Kylli, P., Nousiainen, P ., Biely, P., Sipilä, J., Tenkanen, T & Heinonen, M. 2008. Antioxidant Potential of Hydroxycinnamic Acid Glycoside Esters. Journal of Agricultural and Food Chemistry , 56: 4797-4805) via HPLC coupled to diode array detectors and fluorescence. The results obtained appear in table 2.

TABLE 2 Profile of phenolic compounds of the fruits of Arbutus unedo L. obtained by HPLC. Content expressed in mg of equivalents / 100 grams of fruit (dry matter)

2

Example 2 Procedure for obtaining an extract with antioxidant activity from Arbutus unedo L.

The procedure began with the washing and pre-cutting of the fruits of Arbutus unedo L. collected at their optimum ripening time. The pre-cut fruits were mixed with a 7: 3 water: ethanol mixture in a 1: 5 ratio in a nalgene® centrifuge bottle.

The extraction was carried out in a system of homogenization of Sorvall Omni Mixer blades for 5 minutes at 3000 r.p.m. During the chopping procedure the boat for centrifuge was introduced in ice water to prevent the content temperature would rise to 35 ° C. After the process of chopped the canister with the homogenate was subjected to centrifugation (2000 r.p.m. 5 minutes) to separate the resulting solids from the homogenization process.

The supernatant obtained was passed through a filter paper and was cooled to its concentration by vacuum distillate.

Once the supernatant is obtained hydro-alcoholic of the madroño of the previous phase This was subjected to a concentration by vacuum distillation. The vacuum concentration and low temperatures allows to preserve the antioxidant activity of the extracted compounds. The process of concentration was carried out on a rotary vacuum evaporator (Heidolph model W2000) coupled to a Büchi vacuum pump V-700 with Büchi vacuum controller V-850.

Then the characterization and titration of antioxidant activity until level determined for application in meat products by the determination of total phenolic compounds (method Folin-Ciocalteau).

As described in the " state of the art " section of this report, the efficacy of antioxidant extracts in meat systems depends on multiple factors such as the product matrix, the concentration of phenolic compounds or the presence of other antioxidants. For this reason, a series of initial tests were carried out to determine the optimum level of incorporation of the extract with antioxidant activity obtained from Arbutus unedo L. On the other hand, due to the nature of the source of extraction of the active compounds (wild fruits) It is necessary to characterize the effectiveness of the extracts obtained, as there may be variations depending on the place or time of collection. After a series of initial experimental tests on various meat products, it was determined that the optimal use of the extract of Arbutus unedo L. is between 200-400 ppm (parts per million; mg / kg of meat product), expressed in acid equivalents Gallic as described in Example 1.1.

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Example 3 Application in meat products by incorporation into the formula or by direct spray micro spray

The form of application of the extract of the fruit of Arbutus unedo L varied depending on the type of meat product to which it was intended.

The effectiveness of the extract has been tested by direct surface application by Spray micro-spray prior filtration with 0.65 micron membrane filter; This method of application has been tested on non-minced products such as fresh or marinated meat packaged in modified atmospheres.

The results are shown below. obtained through a fresh and treated meat product thermally incorporated directly into the product mass at a 300 ppm concentration.

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Example 4 Test conditions of the data presented in figures 1 to 4

The data shown in Figures 1 to 4 correspond to an example of the use of the extract of the fruit of Arbutus unedo L. made in hamburgers (control batches and with addiction of the extract of the present invention) fresh and cooked that were subjected to a period of refrigeration. The manufacturing and storage procedure is briefly described below.

Preparation of hamburgers : The initial composition of hamburgers per kilo of fresh dough was as follows:

725 grams of pork tenderloin

250 grams of Water

25 grams of Salt

The processing of the product began with a crude chopping of the meat. In the bowl of a cutter, the chopped meat, salt and concentrated extract (except in the control lot) of the Arbutus unedo L. (300 ppm relative to the final product) diluted in the water of the product formula were added. The dough was subjected to a finely chopped process for 6 minutes in a vacuum cutter until a fine and homogeneous paste was obtained; Subsequently, hamburgers (weight 100 grams) were made using an apparatus for this purpose.

Burger cooking: Part of the hamburger obtained (control batches and extract of the invention) underwent a cooking process in a convection oven (180ºC / 15 minutes).

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Period of refrigeration of the hamburgers : Subsequently to the elaboration of the hamburgers (fresh and cooked) they underwent a commercial refrigeration process of 12 days, at a temperature of 2ºC under fluorescent lighting with a light / dark cycle of 12 hours. The objective of this procedure was to simulate the storage conditions of a commercial linear. On days 1, 4, 8 and 12 of the cooling period burgers were extracted and stored at -80 ° C until analysis to track oxidative phenomena during the cooling period.

Claims (15)

1. Procedure for obtaining an extract with antioxidant properties from the fruit of Arbutus unedo L. which comprises the following stages: (a) extraction from crushed fruit with a solvent selected from water, ethanol or mixtures thereof and obtaining a supernatant (b) concentration of the supernatant resulting from step (a) by vacuum distillation.

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2. The procedure according to the claim 1, wherein the solvent used is a mixture of ethanol and water in the ratio of 7: 3. 3. The method according to claim 1 or 2, in which step (a) is carried out in a system of homogenization and at a temperature equal to or less than 35 ° C. 4. The procedure according to a any of the preceding claims, wherein the distillation of the extract is carried out in a vacuum column or in an evaporator rotary. 5. The procedure according to any of the preceding claims, comprising an additional step characterization and titration of antioxidant activity according to the determination of the total phenolic compounds carried out according to the Folin-Ciocalteau method. 6. Extract of the fruit of Arbutus unedo L. with antioxidant properties obtainable by the method according to any one of the preceding claims. 7. Procedure to prepare a composition foodstuff comprising the addition thereto of an extract according to claim 6. 8. Method according to claim 7, in that the food composition is a meat product. 9. Method according to claim 8, in which the addition is carried out by direct incorporation of the extract in the composition of the meat product. 10. Method according to claim 8, in which the addition is carried out by direct incorporation into the surface of the meat product by spray micro spray. 11. Food composition comprising the extract according to claim 6. 12. Food composition according to claim 11, characterized in that it is a meat product. 13. Food composition according to claim 12, wherein the meat product is selected from group formed by a raw meat product, a meat product heat treated, a cured raw meat product, a product Marinated meat and its mixtures. 14. Food composition according to claim 12 or 13, wherein the extract is present in an amount characterized by being able to inhibit the oxidative processes of lipids and / or proteins in a meat product. 15. Food composition according to claim 14, wherein said amount is such that the content of total polyphenols presented is 200-400 mg of equivalents of gallic acid per kg of meat product, said content of the phenolic compounds having been determined according to the Folin-Ciocalteau method.