Soybean lecithin coated with a biopolymer may provide an encapsulation technique for a range of ingredients, according to a study from an international team of researchers.
Ellagic acid, a polyphenol with antioxidant activity, was used as a test substance and encapsulated in a liposome made from soybean lecithin, which was subsequently coated in a biopolymer composed of chitosan and dextran sulphate, researchers report in the Journal of Functional Food.
The biopolymer-coated liposomes were found to possess good stability to heat and pH, as well as improved release properties than non-coated liposomes, said the researchers, led by Sergio Madrigal-Carballo from the National University in Costa Rica.
“Our results indicate that biopolymer-coated liposomes can be used to encapsulate, stabilize and deliver ellagic acid and may subsequently be of significant interest as novel biomaterial for the improved delivery of variety of functional food components, such as flavours, bioactive lipids, enzymes, peptides, antimicrobials and antioxidants,” wrote Madrigal-Carballo and his co-workers from the University of Wisconsin in the US and the University of Valencia in Spain.
Ellagic acid and beyond
Commenting independently on the research, Winston Samuels, PhD, president & CEO of Maxx Performance Inc, a company specialising in microencapsulation, told FoodNavigator that the system is almost like a gel cap/soft gel capsule which is a form of encapsulation.
“It may have applications in systems that have a temperature less than 25 to 70 °C since it becomes unstable when subjected to temperatures within this range,” he added.
Dr Samuels also added that the system may be specific to ellagic acid. Ellagic acid has been receiving increased interest from researchers with a range of potential benefits reported, including radical scavenging, chemopreventive, antiviral, and antibacterial properties. Studies have shown, however, that the compound is rapidly metabolised by intestinal microorganisms and eliminated from the body.
Madrigal-Carballo and his co-workers formulated what they described as a “novel delivery system” by using electrostatic deposition of chitosan and dextran sulphate onto soybean lecithin liposomes.
The resulting particles were found to be nanosized, spherical and stable, said the researchers. The diameter of the resulting particles was an average of 386.5 nm.
“Biopolymer-coated liposomes loaded with ellagic acid exhibited better thermal and pH stability, as well as better release properties than bare liposomes during cumulative release studies for 15 days,” they noted.
The researchers noted that more research is needed to further develop the encapsulation system and to investigate its applicability to other ingredients. However, when contacted by FoodNavigator, none of the researchers were available for additional comment.
Source: Journal of Functional Foods
Published online ahead of print, doi: 10.1016/j.jff.2010.01.002
“Biopolymer coating of soybean lecithin liposomes via layer-by-layer self-assembly as novel delivery system for ellagic acid”
Authors: S. Madrigal-Carballo, S. Lim, G. Rodriguez, A.O. Vila, C.G. Krueger, S. Gunasekaran, J.D. Reed