OIL-IN-WATER EMULSIONS COMPRISING A POLYUNSATURATED FATTY ACID AND METHODS OF MAKING THE SAME
The present invention relates to stable oil-in-water emulsions comprising a polyunsaturated fatty acid, an emulsifier, water, a metal chelating agent, and an antioxidant, and processes for preparing the stable oil-in-water emulsions. The stable oil-in-water emulsions are substantially free from coalescence, flocculation, Ostwald ripening, and creaming, for a period of at least five months at a temperature of about 4° C.
1 . An oil-in-water emulsion comprising:
a) an oil containing a polyunsaturated fatty acid;
b) an emulsifier;
c) water;
d) a metal chelating agent; and
e) an antioxidant;
wherein the metal chelating agent is present in an amount from about 3% to about 20% by weight of the emulsion and wherein the antioxidant is present in an amount from about 2% to about 20% by weight of the emulsion.
2 . The emulsion of claim 1 , wherein the ratio of metal chelating agent to antioxidant is about 1:3 to about 3:1.
3 . The emulsion of claim 1 , wherein the metal chelating agent is selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), citric acid, citrate, tartaric acid, ascorbic acid, phosphoric acid, a polyphenol, a pyrophosphate, a hexmetaphosphate, whey, casein and combinations thereof.
4 . The emulsion of claim 1 , wherein the antioxidant is selected from the group consisting of vitamin C, vitamin E (tocopherols), a polyphenol, a phenol derivative, carnosic acid, lipoic acid, taurine, an aromatic carboxylic acid, salts of an aromatic carboxylic acid, and combinations thereof.
5 . The emulsion of claim 1 , wherein the emulsion comprises from about 2% to about 6% sodium ascorbate by weight of the emulsion and from about 0.05% to about 0.5% tocopherols by weight of the emulsion.
6 . The emulsion of claim 1 , wherein the polyunsaturated fatty acid is selected from the group consisting of α-linolenic acid, ω-3 eicosapentaenoic acid, ω-3 docosapentaenoic acid, ω-docosahexaenoic acid, γ-linolenic acid, linoleic acid, arachidonic acid, ω-6 docosapentaenoic acid, and combinations thereof.
7 . The emulsion of claim 1 , wherein the polyunsaturated fatty acid is present in a concentration of about 5% to about 40% by weight of the emulsion.
8 . The emulsion of claim 1 , wherein the concentration of the polyunsaturated fatty acid is about 50 mg to about 80 mg per gram of emulsion.
9 . The emulsion of claim 1 , wherein the water is present in a concentration of about 20% to about 75% o by weight of the emulsion.
10 . The emulsion of claim 1 , wherein the emulsifier is selected from the group consisting of gum acacia, modified gum acacia, a lecithin, agar, ghatti gum, modified ghatti gum, pectin, carrageenan, a xanthan gum, a modified food starch, a modified alginate, a polyoxyethylene sorbitan, a fatty alcohol, and combinations thereof.
11 . The emulsion of claim 1 , wherein the emulsifier is present in a concentration of about 5% to about 40% by weight of the emulsion.
12 . The emulsion of claim 1 , wherein the emulsion has an average particle size of about 20 nm to about 1.5 μm.
13 . The emulsion of claim 1 , wherein the emulsion has a viscosity of about 200 to about 1400 mPas at 1 s −1 at 25° C.
14 . The emulsion of claim 13 , wherein the emulsion has a viscosity of about 700 to about 1500 mPas at 1 s −1 at 25° C.
15 . The emulsion of claim 1 , wherein the emulsion has a pH of about 2 to about 7.
16 . The emulsion of claim 1 , further comprising a taste-masking agent.
17 . The emulsion of claim 1 , further comprising an excipient selected from the group consisting of an antimicrobial agent, a preservative, a flavorant, a flavor enhancer, a sweetener, a colorant, a weighing agent, a water-dispersible or oil-dispersible bioactive agent, or a folded oil.
18 . A beverage comprising the emulsion of claim 1 .
19 . A method of making an oil-in-water emulsion comprising
a) combining water and an emulsifier to provide an aqueous mixture;
b) adding to the aqueous mixture a polyunsaturated fatty acid while mixing to provide an oil-in-water emulsion; and
c) adding to the oil-in-water emulsion a metal chelating agent and an antioxidant;
wherein the metal chelating agent is present in an amount from about 3% to about 20% by weight of the emulsion and wherein the antioxidant is present in an amount from about 2% to about 20% by weight of the emulsion.
20 . The method of claim 19 , wherein the ratio of metal chelating agent to antioxidant is about 1:3 to about 3:1.
21 . The method of claim 19 , wherein the metal chelating agent is selected from the group consisting of ethylenediaminetetraacetic acid (EDTA), citric acid, tartaric acid, ascorbic acid, and combinations thereof.
22 . The method of claim 19 , wherein the antioxidant is selected from the group consisting of vitamin C, vitamin E (tocopherols), a polyphenol, a phenol derivative, carnosic acid, lipoic acid, taurine, an aromatic carboxylic acid, salts of an aromatic carboxylic acid, and combinations thereof.
23 . The method of claim 19 , wherein the emulsion comprises from about 2% to about 6% sodium ascorbate by weight of the emulsion and from about 0.05% to about 0.5% tocopherols by weight of the emulsion.
24 . The method of claim 19 , wherein the polyunsaturated fatty acid is selected from the group consisting of α-linolenic acid, ω-3 eicosapentaenoic acid, ω-3 docosapentaenoic acid, ω-3 docosahexaenoic acid, γ-linolenic acid, linoleic acid, arachidonic acid, ω-6 docosapentaenoic acid, and combinations thereof.
25 . The method of claim 19 , wherein the polyunsaturated fatty acid is present in a concentration of about 5% to about 40% by weight of the emulsion.
26 . The method of claim 19 , wherein the concentration of the polyunsaturated fatty acid is about 50 mg to about 80 mg per gram of emulsion.
27 . The method of claim 19 , wherein the water is present in a concentration of about 20% to about 75% by weight of the emulsion.
28 . The method of claim 19 , wherein the emulsifier is selected from the group consisting of gum acacia, modified gum acacia, a lecithin, agar, ghatti gum, modified ghatti gum, pectin, carrageenan, a xanthan gum, a modified food starch, a modified alginate, a polyoxyethylene sorbitan, a fatty alcohol, and combinations thereof.
29 . The method of claim 19 , wherein the emulsifier is present in a concentration of about 5% to about 40% by weight of the emulsion.
30 . The method of claim 19 , wherein the emulsion has an average particle size of about 20 nm to about 1.5 μm.
31 . The method of claim 19 , wherein the emulsion has a viscosity of about 200 to about 1400 mPas at 1 s −1 at 25° C.
32 . The emulsion of claim 31 , wherein the emulsion has a viscosity of about 700 to about 1500 mPas at 1 s −1 at 25° C.
33 . The method of claim 19 , wherein the emulsion has a pH of about 3 to about 5.
34 . The method of claim 19 , wherein the emulsion further comprises a taste-masking agent.
35 . The method of claim 19 , wherein the emulsion further comprises an excipient selected from the group consisting of an antimicrobial agent, a flavorant, a flavor enhancer, a sweetener, a colorant, a weighing agent, a water-dispersible or oil-dispersible bioactive agent, or a folded oil.
36 . An oil-in-water emulsion made by the process of claim 19 .