|LIU, FEI - Jiangnan University|
|ANTONIOU, JOHN - Jiangnan University|
|LI, YUE - Jiangnan University|
|Yokoyama, Wallace - Wally|
|MA, JIANGUO - Jiangnan University|
|ZHONG, FANG - Jiangnan University|
Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/31/2015
Publication Date: 3/31/2015
Citation: Liu, F., Antoniou, J., Li, Y., Yokoyama, W.H., Ma, J., Zhong, F. 2015. Preparation of gelatin films incorporated with tea polyphenol nanoparticles for enhancing controlled-release antioxidant properties. Journal of Agricultural and Food Chemistry. 63(15):3987–3995. https://doi.org/10.1021/acs.jafc.5b00003.
Interpretive Summary: The antioxidant properties of tea polyphenols, a well known bioactive compound, were evaluated in a gelatin matrix or encapsulated and embedded in a gelatine matrix. The properties of antioxidants are usually measured in homogeneous solutions. However, tea polyphenols may alter the taste of foods so encapsulation was evaluated as a means of using this food approved antioxidant to avoid sensory problems. TPP carried partially in the gelatine film and partially embedded in nanoparticles was most efficient at preventing oxidation.
Technical Abstract: Tea polyphenols (TP) were incorporated into edible gelatin films either alone or incorporated into nanoparticles in order to determine the physico-chemical properties of the film and the antioxidant properties of TP in a solid gelatin matrix. The TP containing nanoparticles were prepared by cross-linking chitosan hydrochloride (CSH) with sulfobutylether-ß-cyclodextrin sodium (SBE-ß-CD) at three different encapsulation efficiencies (EE, ~50%, ~80% and ~100%) of TP by adjusting the concentration of CSH. Composite films showed no significant difference in visual aspects while light transmission (250-550 nm) was improved with incorporation of TP. Nanoparticles appeared to be homogeneously dispersed within the gelatin matrix by microstructure analysis (SEM and AFM). TP loaded films had ferric reducing and DPPH radical scavenging power that corresponded to their EE. Sunflower oil packaged in,bags made of gelatin film embedded with 80% EE of nanoparticles showed the best oxidation inhibitory effect, followed by 100% EE, 50% EE and free TP over a long period (6 weeks). However, when the gelatine film was placed over the headspace and not in contact with the oil thefree TP showed the best effect. The results indicate that TP at the surface can inhibit free radical oxidation of fats and that the effect depends on the ratio of free to encapsulated TP in the film.