Fine Particles Science and Technology pp 761-775 | Cite as
Preparation and Characterization of Nano-Sized Carotenoid Hydrosols
Abstract
Recent developments in the preparation of nano-sized beta-carotene hydrosols by polymer- and surfactant-controlled precipitation and phase separation techniques are described.
As found with electron microscopy and quasielastic light scattering dispersions are obtained with core-shell-type particles of the size range between 15 nm and 250 nm. From electrophoretic mobility measurements it is concluded that colloidal stabilization of the gelatin-coated nanoparticles is governed by steric effects. The stability of the beta-carotene loaded mixed micelles with particle sizes of ~ 20 nm is based on enthalpic stabilization effects of the ethoxylated fatty acid surfactant used as solubilizer.
Concomitant with changes in particle size and state the UV/VIS-spectra of the different preparations exhibit characteristic shifts in respect with the electronic absorption spectra of dilute molecular solutions. The red shifts observed with crystalline dispersions and the blue shifts found in precipitates and solubilizates are interpreted as caused by process-controlled head-to-tail and card-pack aggregation structures, respectively.
The corresponding control of colour shade and strength and the enhanced bioavailability of the obtained formulations provide the basis for numerous new applications for carotenoids in the pigmentation of foodstuffs and feed and in pharmaceutical preparations.
Keywords
Nonionic Surfactant Colour Shade Molecular Solution Latex Dispersion Electrophoretic Mobility MeasurementPreview
Unable to display preview. Download preview PDF.
References
- 1.Bauernfeind, J.C., Brubacker, G.B., Kläui, H.M., and Marusich, W.C. (1971) Use of carotenoids, in O. Isler (ed.), Carotenoids, Birkhäuser Verlag, Basel/Stuttgart, pp. 743–770.Google Scholar
- 2.Kläui, H.M., Bauernfeind, J.C. (1981) Application Forms, in J.C. Bauernfeind (ed.), Carotenoids as Colourants and Vitamin A Precursors, Academic Press, Boston, pp. 86–102.Google Scholar
- 3.Horn, D. (1989) Preparation and characterization of microdisperse bioavailable carotenoid hydrosols, Angew. Makromol. Chem. 166/167, 139–153.Google Scholar
- 4.Chu, B. (1991) Laser Light Scattering, Academic Press, Boston.Google Scholar
- 5.Unterforsthuber, K., Lilge, D., Lüddecke, E., Horn, D., and Wu, C. (1992), Determination of particle size distribution by an analysis of intensity constrained multi-angle photon correlation spectroscopy data, Proc. 5. European Symp. Particle Characterization, Nürnberg, pp. 70–81.Google Scholar
- 6.Horn, D. and Heuck, C.C. (1983) Charge determination of proteins with polyelectrolyte titration, J. Biol. Chem. 258, 1665 - 1670.Google Scholar
- 7.Auweter, H. and Horn, D. (1985) Fiber-optical quasi-elastic light scattering of concentrated dispersions, J. Colloid Interface Sci. 105, 399–409.CrossRefGoogle Scholar
- 8.Wiese, H. and Horn, D. (1991) Single-mode fibers in fiber-optic quasielastic light scattering: A study of the dynamics of concentrated latex dispersions, J. Chem. Phys. 94, 6429–6443.CrossRefGoogle Scholar
- 9.Wiese, H. and Horn, D. (1993) Fiber-optic quasielastic light scattering in concentrated dispersions: The on-line process control of carotenoid micronization, Ber. Bunsenges. Phys. Chem.97, 1589–1597.Google Scholar
- 10.Dickinson, E. and Stainsby, G. (1982) Colloids in Food, Applied Science, London.Google Scholar
- 11.Dickinson, E. (1986) Mixed proteinaceous emulsifiers: review of competitive protein adsorption and their relationship to food colloid stabilization, Food Hydrocolloids 1, 3 - 23.CrossRefGoogle Scholar
- 12.Hiemenz, P.C. (1977) Principles of Colloid and Surface Chemistry, Marcel Dekker, New York/Basel.Google Scholar
- 13.Maxey, C.R. and Palmer, M.R. (1976) The isoelectric point distribution of gelatin, in R.J. Cox (ed.), Photographic Gelatin, Academic Press, London, pp. 27–36.Google Scholar
- 14.Gaier, K. (1990) Diploma Thesis, Optische Spektroskopie an Beta-CarotinEinkristallen, Universität Stuttgart.Google Scholar
- 15.Wloch, E., Wieckowski, S., and Turek, A.M. (1987) Spectroscopic characteristics of the long-wavelength absorbing form of beta-carotene, Photosynthetica 21, 2 - 8.Google Scholar
- 16.Sterling, C. (1964) Crystal-structure analysis of beta-carotene, Acta Cryst. 17, 1224–1228.CrossRefGoogle Scholar
- 17.Kasha, M. (1963) Energy transfer mechanisms and the molecular exciton model for molecular aggregates, Radiation Res. 20, 55–71.CrossRefGoogle Scholar
- 18.Kasha, M., Rawls, H.R., and El-Bayoumi, M.A. (1965) The exciton model in molecular spectroscopy, Pure Appl. Chem.11, 371–392.CrossRefGoogle Scholar
- Krinski, N.I. (1971) Function, in [1], pp. 669–716.Google Scholar
- 20.Krinski, N.I. (1979) Carotenoid Protection against oxidation, Pure Appl. Chem.51, 649–660.CrossRefGoogle Scholar
- 21.Nishimura, M. and Takamatsu, K. (1960) Studies on a carotene protein complex isolated from green leaves, Plant Cell Physiol. 1, 305–309.Google Scholar