PIGMENT-LOADED SOLID LIPID NANOPARTICLES
Solid lipid nanoparticles (SLNs) and suspensions thereof in an aqueous phase are provided, in which the SLNs have high content of oil-soluble pigment and high stability. A food product, such as a beverage, comprising said SLNs is also provided.
1 . A solid lipid nanoparticle (SLN) comprising:
(a) a core comprising:
(i) a lipid having a melting point above 40° C., and
(ii) an oil-soluble pigment
(b) a dual surfactant system comprising:
(i) a polysorbate, and
(ii) a phospholipid
wherein the ratio of polysorbate:phospholipid (i:ii) in said dual surfactant system is between 10:1 and 1:10 and the amount of pigment constitutes 5-40% w/w of said SLN.
2 . The SLN according to claim 1 , wherein said SLN further comprises an antioxidant.
3 . The SLN according to claim 1 , wherein said antioxidant is present in an amount of between 1 and 10% w/w of said SLN.
4 . The SLN according to claim 1 , wherein said lipid is present in an amount of between 30 and 70% w/w of said SLN.
5 . The SLN according to claim 4 , wherein said lipid is a fully saturated triglyceride.
6 . The SLN according to claim 1 , wherein said oil-soluble pigment is a carotenoid or a chlorophyll.
7 . The SLN according to claim 6 , wherein the carotenoid is a lycopene or a beta-carotene.
8 . The SLN according to claim 1 , wherein said dual surfactant system is present in an amount of between 20% w/w and 75% w/w of said SLN.
9 . The SLN according to claim 1 , wherein the ratio of polysorbate:phospholipid (i:ii) in said dual surfactant system is between 10:1 and 1:1.
10 . The SLN according to claim 1 , wherein said polysorbate is polysorbate 80.
11 . The SLN according to claim 1 , wherein said phospholipid is selected from sunflower lecithin, soy bean lecithin, cotton seed lecithin, rape seed lecithin, and egg yolk lecithin.
12 . The SLN according to claim 1 , having a mean Z-average particle size, measured by dynamic light scattering, of less than 500 nm.
13 . A suspension comprising solid lipid nanoparticles (SLNs) according to claim 1 suspended in an aqueous phase.
14 . The suspension according to claim 13 , wherein said suspension comprises:
(i) said lipid having a melting point above 40° C., in an amount of 10-35% w/w of the total suspension;
(ii) said oil-soluble pigment, in an amount of 1-20% w/w of the total suspension; and
(iii) said dual surfactant system, in an amount of 1-25% w/w of the total suspension.
15 - 20 . (canceled)
21 . A suspension comprising first solid lipid nanoparticles according to claim 1 (SLN-1) and second solid lipid nanoparticles according to claim 1 (SLN-2) in a single aqueous phase, wherein the oil-soluble pigments in each of SLN-1 and SLN-2 are different.
22 . A food, beverage, dietary supplement or pharmaceutical product, comprising solid lipid nanoparticles according to claim 1 .
23 . A method of coloring a food, beverage, dietary supplement or pharmaceutical product comprising adding solid lipid nanoparticles according to claim 1 to the food product.
24 . A method for producing a suspension of solid lipid nanoparticles (SLNs) according to claim 1 , comprising:
(A) heating a liquid oil phase comprising said lipid having a melting point above 40° C. and said oil-soluble pigment, so as to dissolve said oil-soluble pigment;
(B) mixing an aqueous phase comprising said dual surfactant system with said liquid oil phase from step (A) in a high shear mixer to create an emulsion;
(C) passing the emulsion from step (C) through a homogenizer to obtain a homogenized mixture; and
(D) cooling the homogenized mixture from step (D), thereby obtaining a suspension of solid lipid nanoparticles (SLNs).
25 - 27 . (canceled)
28 . The SLN according to claim 2 , wherein the antioxidant comprises α-tocopherol.
29 . The SLN according to claim 5 , wherein said lipid is a fully saturated triglyceride selected from fully hydrogenated sunflower oil, fully hydrogenated rapeseed oil fully hydrogenated palm oil, and fully hydrogenated soybean oil.