Polyunsaturated fatty acid-enriched oil composition

Abstract

The present invention relates to a polyunsaturated fatty acid-enriched oil composition consisting of an emulsion of a source of polyunsaturated fatty acids in the form of majority triglycerides and a stabilizing agent, characterized in that the oil composition comprises at least one natural chelating agent.

Description

Oil composition enriched with polyunsaturated fatty acids Technical field of the invention

[0001] The present invention relates to the field of highly unsaturated oils and in particular oil compositions enriched with polyunsaturated fatty acids, in particular in the form of a stable emulsion suitable for incorporation into foodstuffs or dermo-cosmetics. These oils are in particular fish oils, algae oils or vegetable oils. They are obtained by a cold-pressed extraction process.

[0002] Highly unsaturated oils are very sensitive to oxidation induced by the presence of oxygen, heat, metals, water, etc. It is therefore essential to protect them against oxidation in order to preserve their nutritional and organoleptic qualities and their shelf life.

[0003] Docosahexaenoic acid (DHA), for example, is subject to a natural process of oxidative degradation of lipids occurring when an unsaturated lipid is in the presence of oxygen or light. To counteract this degradation process and to preserve the beneficial effects of DHA, the applicant has already developed a process for stabilizing oils rich in polyunsaturated fatty acids against oxidation. This process combines the destruction of lipoxygenases present in the oil and the addition of antioxidant compounds in order to preserve the nutritional and organoleptic qualities of the oil and to delay the initiation of oxidation. Comparison of induction times (time at the end of which oxidation reactions begin to propagate) evaluated by the Rancimat method shows that the oils having undergone this process known under the trademark "Qualitysilver ®» have a stability 2 to 7 times greater than standard oils containing a natural mix of antioxidants (tocopherols) State of the art

[0004] Known in the state of the art is patent application EP1905425 which relates to vesicles which comprise a hydrophobic internal cavity essentially free of organic solvent and at least one bilayer consisting of two layers of amphiphilic lipids defining between them a hydrophilic interstitial space. The aim is to form uni- or multivesicular structures and not emulsions. This document does not disclose a composition consisting of an emulsion, and not a liposomal composition. In this solution, there is no chelation reaction, since the compound of interest is protected by the fatty phase formed by the lipid bilayers.

[0005] Patent application US2011 / 105433 relates to the prevention and / or inhibition of the generation of off-flavors in food products. In particular, the present invention relates to the formulation of mixtures of lipid raw materials and food products containing long-chain polyunsaturated fatty acids, and to compositions and methods for stabilizing these products against the formation of off-flavors, such as off-flavors of fish. In particular, this patent application provides a composition comprising an oil-containing LC-PUFA and lecithin, the weight ratio of lecithin to LC-PUFA being at least about 25:75. In particular, it provides a composition comprising an oil-containing LC-PUFA and lecithin, the weight ratio of lecithin to LC-PUFA being at least about 25:75.

[0006] This document does not concern emulsions but etherogenic fatty acids

[0007] Patent application US2013 / 059768 describes lipid compositions comprising phospholipids having a high content of docosahexaenoic acid (DHA), these compositions preferably being extracted from natural sources. The lipid compositions are excellent sources of highly bioavailable DHA and can be used in oral carriers, dietary supplements, functional foods, etc.

[0008] Patent application US2007 / 298083 describes a stable aqueous emulsion containing water, an ester mixture containing esters of polyunsaturated fatty acids, such as omega-3 fatty acids, emulsifiers and stabilizers. The emulsion can be used as a beverage or as an additive that can be added to a beverage or food product. The emulsion provides available and stable omega-3 fatty acids without an undesirable rancid odor.

[0009] Patent application US2016 / 345618 relates to an aqueous omega-3 fatty acid composition comprising: a) water; b) a high HLB non-ionic emulsifier with HLB > 10; and c) a marine oil, an algal-derived oil or a vegetable oil rich in omega-3 fatty acid and comprising a total of glycerides having a monoglyceride (MG), a diglyceride (DG) and a triglyceride (TG) of the omega-3 fatty acid, the TG of the omega-3 fatty acid content in the composition being less than 80% of the total glycerides. Disadvantages of the prior art

[0010] The emulsions thus prepared according to the solutions of the prior art and in particular according to the Qualitysilver (TM) process are generally satisfactory. However, when they are subsequently added to food or dermo-cosmetic products whose preparation requires a step where they are subjected to a high temperature (typically around 120° and / or prolonged (typically more than 60 seconds), a degradation is observed resulting in organoleptic qualities that are difficult to accept for qualitative products.

[0011] The problem of oxidation of additives according to the state of the art also appears when they are added to certain types of foods containing iron, for example dairy products or when adding water, which results in the addition of minerals which can lead to a degradation of the solutions of the prior art and a phenomenon of rancidity.

[0012] The present invention aims to address these drawbacks. To this end, the invention relates to an oil composition enriched with polyunsaturated fatty acids having the characteristics set out in claim 1.

[0013] The composition consists of an emulsion of a source of polyunsaturated fatty acids in the majority triglyceride form and a stabilizing agent characterized in that it contains a natural chelating agent.

[0014] The subject matter of the present invention may also have one or a compatible combination of the following characteristics.

[0015] The oil composition includes: Glycerol 99.5% Algal oil rich in DHA; more generally an oil from microorganisms or micro-algae rich in DHA Sucro-esters and / or lyso-phosphatidylcholine and / or lecithin Chelating agent.

[0016] Advantageously, the composition further comprises DPAn-6 and in that its content is between 0.1% and 20% by mass relative to the total weight of the oil in the composition. DPAn-6 denotes omega-3 docosapentaenoic acid or Osbond acid / C22:5 n-6)

[0017] According to a particular embodiment, said algae oil provides a concentration greater than 50 mg of DHA and / or EPA per g of emulsion.

[0018] Advantageously, said chelating agent consists at least in part of citric acid and / or tartaric acid, preferably solubilized in glycerol, in the presence of phospholipids.

[0019] According to another variant, said chelating agent consists of a phosphatidylcholine.

[0020] According to another variant, said chelating agent consists of a lysophosphatidylcholine.

[0021] According to another variant, said chelating agent consists of ascorbic acid.

[0022] According to another variant, it is made up of polyphenols, e.g. green tea

[0023] Advantageously, the composition is formed of lipid globules surrounded by Lyso PC molecules.

[0024] The invention also relates to a food enriched with omega 3 consisting of providing a food with a composition in accordance with one of the preceding claims.

[0025] Description of non-limiting examples of implementation

[0026] The present invention will be better understood on reading the following description, concerning a non-limiting example of embodiment illustrated by the appended drawings where:

[0027] The figure represents a schematic view of the skin of a lipid droplet obtained by the method according to the invention. General principle of the invention

[0028] The aim of the invention is to provide additives for enriching food or dermo-cosmetic products with polyunsaturated fatty acids which are resistant to intermediate treatments at high temperatures, by means of a composition and in particular a pre-emulsion prepared in accordance with the process of the prior art, with the addition of a chelating agent, in particular a phosphatidylcholine, optionally in a form derived from lyso-phosphatidylcholine or citric acid solubilized in glycerol.

[0029] The result of the invention is to strengthen the micellar membrane surrounding the oily phase containing DHA, which has several advantages:

[0030] First, this strengthening reduces the degradation of the oil containing DHA, and thus avoids the rancidity observed with the prior art solutions.

[0031] The presence of a chelating agent at the membrane-oil interface reduces oil degradation and the resulting rancid sensation.

[0032] Finally, the strengthening and structure of this membrane slows down its destruction during digestion of the enriched product and during passage of stomach barriers, which improves the availability of DHA at the plasma and lymphatic level.

[0033] The lymphatic bioavailability study investigating the overall absorption of DHA expressed in mg / mL*h of DHA in rats subjected to lymphatic duct fistulation (n=6 rats / group) and receiving an equivalent of 300mg of DHA over a period of 6 hours shows that this absorption is significantly higher for the DHA pre-emulsion (24 mg / ml*h) compared to the same oil composing this emulsion (17 mg / ml*h). First example of preparation

[0034] The first example of preparation concerns a composition comprising a sucro-ester alone or combined with lyso-phosphatidylcholine (Lyso-PC).

[0035] The first step consists of preparing a polar phase by mixing a proportion of 60% glycerol and 4% sucroester; and heating this preparation to a temperature of 80° until the mixture reaches this temperature. This step is advantageously carried out in a vacuum reactor or under a nitrogen atmosphere.

[0036] At the same time, an oily apolar phase containing DHA and a chelating agent, for example lyso-phosphatidylcholine, is prepared by heating it to a temperature of 80°C, in the absence of air, for example under vacuum or nitrogen atmosphere.

[0037] Alternatively, the chelating agent can be introduced, depending on its water-soluble nature, into the polar phase whereas it will rather be introduced into the apolar phase when it is liposoluble, or indifferently in amphiphilic media.

[0038] The polar phase is then introduced into the reactor under vacuum or under a nitrogen atmosphere containing the apolar phase at 80°C by progressive incorporation with stirring by a rotor-stator stirrer for emulsion to obtain a homogeneous product. For example, stirring of a 3.6 kg mixture is carried out for a period of 10 minutes at a speed of 10,000 to 15,000 revolutions per minute. The reactor is maintained at a temperature of 80°C during this emulsification step.

[0039] The rotor-stator is then stopped and the mixer is kept active, and, in the case of a vacuum reactor, nitrogen is introduced to restore atmospheric pressure and prevent the introduction of oxygen into the reactor.

[0040] The emulsion thus prepared is then taken and packaged in an opaque container under an inert atmosphere.

[0041] When the composition thus prepared is introduced into water, a homogeneous dispersion of stable micelles is obtained, the oily phase rich in DHA being encapsulated in a membrane formed by the phospholipid, with a diameter of the order of 0.4 µm.

[0042] This composition remains stable even when the product in which it is found is in the presence of iron, the phospholipid membrane remaining closed and limiting the migration of the oily phase. The chelating agent introduced during the preparation of the composition will be found at the interface between the membrane and the oily core containing the DHA, and will ensure the chelation of the iron preventing the penetration of iron into the oily phase.

[0043] When the chelating agent is formed by lyso-phosphatidylcholine, a strengthening of the membrane is observed, giving the micelles better envelope stability and improved resistance when the product is heated, thereby delaying the phenomenon of rancidity due to denaturation of the oily phase.

[0044] Composition with alyso-phosphatidylcholine without sugar ester

[0045] An alternative embodiment consists of preparing a polar and / or apolar phase containing lyso-phosphatidylcholine (1) alone or in a mixture with phosphatidylcholine (2) or more broadly lecithin. The rest of the process is unchanged. The droplets obtained according to this alternative have a skin illustrated by the.

[0046] The use of lyso-phosphatidylcholine, i.e. with one less hydrophobic tail, allows for better closure of lipid droplets by optimizing the curvature.

[0047] This variant is more resistant for applications in the preparation of acidic foods, for example drinks, generally acidic (fruit juices, syrups, etc.).

[0048] In addition, the use of lyso-PC allows the formation of smaller particles, even without using pressure when making the emulsion (often at more than 400 bars, or even 1000 bars).

[0049] The emulsion particle size corresponds to a particle size of approximately 0.2 µm with lyso-PC as emulsifier (emulsion made in the vacuum reactor). The reduced size of the lipid droplets allows for an increase in the contact surface. This counteracts the desired oxidative stabilization effect, but the oil droplets are better closed with Lyso-PC and more stable (no coalescence).

[0050] With Lyso-PC, the addition of additional surfactant for emulsion stabilization is not necessary.

[0051] Example of preparing a food enriched with omega 3

[0052] The above-mentioned composition is for example intended for the preparation of a syrup enriched with omega 3. The process consists of adding 10% of emulsion containing DHA to a syrup, which contains citric acid reinforcing the chelating action of the composition according to the invention.

[0053] Lipid oxidation is more important at acidic pH. The addition of citric acid provides a chelating effect on metals (iron), and reinforces the chelating effect of phospholipids.

[0054] Example of preparing a food enriched with omega 3

[0055] Another example of application concerns the preparation of milk enriched with omega-3; the above-mentioned composition is added to milk at room temperature. The micelles disperse and intercalate between the casein micelles in the milk, without the oily phase rising to the surface. Nature of enriched oils

[0056] The process and composition is applicable to different types of natural microalgae oils containing approximately 40% DHA, or enriched, in particular with DHA, and / or EPA. Preparation of a yogurt enriched with DHA:

[0057] The following example concerns the preparation of a yogurt enriched with DHA according to the invention.

[0058] The preparation process involves the following steps:

[0059] a) Bring 1L of whole cow's milk to a boil (this recipe can also be adapted with plant-based milks and suitable texturizers)

[0060] b) Let the milk cool to 50°C

[0061] c) Add 12.5g of emulsion containing 160mg / g of DHA (the content of the emulsion and the percentage added can be adapted according to the desired content per yogurt)

[0062] d) Homogenize the mixture

[0063] e) Add a sachet of commercial lactic ferments (at a temperature of approximately 45°C)

[0064] f) Homogenize the mixture

[0065] g) Divide 125g of preparation per yogurt pot

[0066] i) Starting the fermentation of yogurts in a classic yogurt maker, 12-hour fermentation cycle

[0067] At the end of the cycle, the yogurts are placed in the refrigerator for at least 4 hours before tasting. Preparation of a DHA-enriched syrup:

[0068] Another example of implementation of the invention concerns the preparation of a syrup enriched with DHA. The initial syrup can be prepared from different sugar bases, for example:

[0069] Sucrose incorporated into water at 70°C to obtain a clear final solution and Brix of 55%

[0070] Agave syrup diluted directly with cold water to obtain a brix of 55%

[0071] To obtain 1L of syrup containing 20mg / g of DHA, add 130g of emulsion containing 160mg / g of DHA and citric acid for chelating action. The emulsion content and the percentage added can be adjusted according to the desired content in the syrup. The emulsion is then dissolved in the syrup by gentle homogenization and then stored at 4°C under an inert atmosphere. Green tea extract

[0072] Another example of implementation of the invention concerns the preparation of a green tea extract (rich in polyphenols) which binds to the interface of the lipid particle.

[0073] The composition is as follows:

[0074] Emulsion base with emulsifying agent Lyso-Phosphatidylcholine

[0075] The stability time is analyzed with a Rancimat ™ bench by adding iron to the emulsion to mimic the foods likely to be enriched with the DHA emulsion and to study the chelating effect of the antioxidants alone or in synergy tested.

[0076] The stability time in the presence of iron (300µM fe2+) is 5.3 hours for a control sample (without treatment according to the invention)

[0077] With an emulsion according to the invention containing 0.057% of Liposoluble catechins, the stability period increases significantly and reaches 11.4 hours, including in the presence of iron.

[0078] With an emulsion according to the invention at 0.057% of Liposoluble catechins + 0.5% citric acid, the stability duration increases significantly and increases to 15.1 hours.

[0079] The addition of 0.5% Citric Acid or 0.2% Green Tea Extract or 0.45% Ascorbyl Palmitate doubles the stability time (approximately 11 hours) thus demonstrating their chelating effects.

[0080] The combination of citric acid 0.5% + ascorbyl palmitate 0.45% has a synergistic effect by reinforcing the chelating effect, i.e. a stability time of 18 hours despite the presence of iron. Other variants

[0081] In order to improve encapsulation (in two phases), a variant consists of preparing a primary emulsion from glycerol + sucrose + oil to obtain stable globules, then stabilizing these globules by adding lecithins in a second step, also with ultra turrax in order to obtain better oxidative stability in the food matrix)

Claims

Oil composition enriched with polyunsaturated fatty acids, consisting of an emulsion of a source of polyunsaturated fatty acids in the form of predominantly triglycerides and at least one stabilizing agent characterized in that it comprises at least one natural chelating agent. Composition according to claim 1, characterized in that the composition further comprises DPAn-6 and in that its content is between 0.1% and 20% by mass relative to the total weight of the oil in the composition. Composition according to any one of the preceding claims, characterized in that it is constituted by the following formulation: Glycerol Microorganism oil rich in DHA and / or EPA Sucro-esters and / or lyso-phosphatidylcholine and / or lecithin Chelating agent. Composition according to claim 3 characterized in that said algae oil provides a concentration greater than 50 mg of DHA and / or EPA per g of emulsion. Composition according to claim 1 or 2, characterized in that said chelating agent consists at least in part of citric acid. Composition according to claim 1, 2 or 5 characterized in that said chelating agent consists at least in part of tartaric acid. Composition according to claim 1 or 2, characterized in that said chelating agent consists of a phosphatidylcholine. Composition according to claim 1 or 2, characterized in that said chelating agent consists of a lysophosphatidylcholine. Composition according to claim 1 or 2, characterized in that said chelating agent consists of ascorbic acid. Composition according to claim 1 or 2, characterized in that said chelating agent consists of polyphenols. Composition according to the preceding claim, characterized in that polyphenols are extracted from green tea. Composition according to claim 1 or 2, characterized in that said chelating agent consists of ascorbyl palmitate. Composition according to claim 1 or 2 characterized in that it forms lipid globules surrounded by Lyso PC molecules. Composition according to claim 1 or 2, characterized in that said chelating agent consists of phytic acid. Composition according to claim 1 or 2, characterized in that it comprises an emulsifying agent consisting of mono-diglycerides of citric acid. Food or food supplement enriched with omega 3 consisting of providing a food with a composition in accordance with one of the preceding claims.

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