Writing in Carbohydrate Polymers, the Penn State food scientists report that corn starch and the fatty acid esters forms of vitamins A and C produced protective pockets in their structure, allowing the heat and acid-sensitive vitamins to be carried into the body.
Ursula Lay Ma, Prof. John Floros and Prof. Gregory Ziegler report that, to form the protective pocket, a certain type of corn starch is required called high amylose maize starch.
When the amylose is mixed with fatty acid ester of vitamin A, for example, a coil is formed: The internal part of the coil repels water (known as hydrophobic), whereas the exterior wall of the coil attracts water (hydrophilic).
The oil-soluble molecules automatically move into the coil that encapsulates the vitamin.
“There's an ideal size and the real work is to get the right balance of the hydrophilic and hydrophobic properties,” explained Ziegler.
The technique may also be applied to other ingredients, like phytosterols, said the researchers.
The study was supported by a grant from the Pennsylvania Agricultural Experiment Station.
The Penn State researchers evaluated the production of what they called ‘inclusion complexes’ combining amylose, amylopectin, and high amylose maize starch with ascorbyl palmitate (a form of vitamin C), retinyl palmitate (a form of vitamin A), and phytosterol esters.
Results showed that only amylose and high amylose maize starch were successful in forming the complexes with all three ingredients.
The best results were observed for the vitamin C compound, followed by vitamin A.
“The results of this study suggest that the formation of starch inclusion complexes with fatty acid esters seems to be limited by the solubility of the compound in the reaction medium and the structure of the molecule forming the ester with the fatty acid,” wrote the researchers.
Looking ahead, the researchers said the initial data indicates that the technology could be applied to food, pharma, and even cosmetics.
Starches are common, biodegradable and easily absorbed, said the researchers, which would make them an inexpensive and environmentally friendly alternative for these industries.
"We have more work and research to do," said Ziegler. "The trick is how can we set this up so we can do it simply."
Source: Carbohydrate Polymers
Volume 83, Issue 4, Pages 1869-1878
“Formation of inclusion complexes of starch with fatty acid esters of bioactive compounds”
Authors: U.V. Lay Ma, J.D. Floros, G.R. Ziegler