Using nanostructured lipid carrier (NLC), scientists report in the Journal of Food Science that carotenoid, naturally insoluble in water (hydrophobic), can be dispersed and stabilised in beverages, tapping into technology originally used by the cosmetics and pharmaceutical industries. "Formulating beta-carotene in colloidal lipid particles of fat-in-water dispersions is a promising method to incorporate beta-carotene into water-dispersible systems," wrote the authors from the Technical University of Berlin and the Free University of Berlin.
"The small particle size of around 400 nm offers the possibility to use NLC as a food colloid in several applications without creaming or sedimentation. Especially, the application as dye and provitamin A source in beverages is a focus of interest," they added. The new study may offer innovative ingredients for the beverage industry. According to the researchers, the nanostructured lipid carrier is prepared by melting the lipid blend at 80 degrees Celsius (solid and liquid lipid plus the active ingredient) and dispersing it into a hot emulsifier solution.
"The aim of the present study is to extend the limited knowledge of using NLC technology to improve the bioavailability of beta-carotene in food systems and to evaluate the feasibility for further applications in this field with focus on beverages," explained the researchers. The Berlin-based researchers report that all particles prepared were in the nano-scale (smaller than one micrometre), with an average particle size of 0.3 micrometres after nine weeks of storage at 20 degrees Celsius, and 30 weeks of storage between four and eight degrees Celsius.
Moreover, they report that the tocopherol (vitamin E) increased protection of beta-carotene against degradation, with poor stability reported when no tocopherol was used in dilution. "To compare the efficiency in protecting beta-carotene in solid lipid nanoparticles/ nanostructured lipid carrier to other dispersion types and technologies, further investigations will take place," wrote the researchers.
"Also, influences on beta-carotene stability in different beverages will be tested (for example, milk, carbonated drinks)," they concluded. Talking to FoodNavigator.com, lead author Anke Hentschel said that the investigations on SLN/NLC technology for food systems are currently at the level of basic research.
"We are looking forward to create cooperation projects with industrial partners. We hope to find interested companies like formulators of beverages, dyes or dairy products. Therefore the time until commercial products will be available is hard to forecast," she said. Commenting on the cost effectiveness of the technology, Hentschel added: "The cost efficiency can only be estimated. The technology is comparable to that of high-pressure homogenization of milk however, a two to three times higher pressure and additional heating is required."
Source: Journal of Food Science Published online ahead of print, OnlineEarly Articles, doi:10.1111/j.1750-3841.2007.00641.x "Beta-Carotene-Loaded Nanostructured Lipid Carriers"
Authors: A. Hentschel, S. Gramdorf, R.H. Müller, T. Kurz