Location: Healthy Processed Foods Research
Title: Beta-carotene encapsulated in food protein nanoparticles reduces peroxyl radical oxidation in Caco-2 cells Authors
Submitted to: Food Hydrocolloids Journal
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 24, 2014
Publication Date: January 12, 2015
Citation: Yi, J., Lam, T.I., Yokoyama, W.H., Cheng, L.W., Zhong, F. 2015. Beta-carotene encapsulated in food protein nanoparticles reduces peroxyl radical oxidation in Caco-2 cells. Food Hydrocolloids Journal. 43:31-40. Interpretive Summary: Nanoparticles containing beta-carotene were prepared by encapsulation of beta-carotene solubilized in a nontoxic organic solvent and then emulsified with food proteins. Evaporation of the solvent resulted in solid beta-carotene core surrounded by protein. We showed that although in solid form the beta-carotene nanoparticles had antioxidative properties in vitro and that beta-carotene was taken up by caco-2 cells and also demonstrated antioxidative properties against peroxyl radicals.
Technical Abstract: Beta-carotene (BC) was encapsulated by sodium caseinate (SC), whey protein isolate (WPI), and soybean protein isolate (SPI) by the homogenization-evaporation method forming nanoparticles of 78, 90 and 370 nm diameter. Indices of the chemical antioxidant assays, the reducing power, DPPH radical scavenging activity, and the hydroxyl radical scavenging activity (OH.) were improved by nanoencapsulation, compared to free BC. Caco-2 cells were treated with dichlorofluorescin diacetate (DCFH-DA) to determine the cellular antioxidant activity (CAA) of BC. DFCH-DA is absorbed into cells, de-esterified and oxidized to dichlorofluorescein, DFC, by peroxyl radicals. DFC is fluorescent. CAA of SC, WPI, and SPI nanoparticles was higher (60%) compared to BC alone (45%). FTIR-ATR showed the presence of BC in the nanoparticle preparations. XRD and DSC analysis suggested that BC is amorphous in the nanoparticles. BC encapsulated by WPI had the most advantageous release properties. Release was low with pepsin but high with trypsin suggesting that WPI might be the best protein delivery vehicle to deliver BC to the intestine.