Text

theses

A number of food components with various health-promoting benefits have been found in many natural plants. Although these phytochemicals show great potential in the functional food market, their bioavailability is a still critical factor that hinders their health benefits. Processing may also induce changes in the properties of food ingredients. In this Master research project, the problem of poor bioavailability of one polyphenol, curcumin, was addressed by developing a novel delivery system. In order to improve its water solubility and oral bioavailability, researchers have tried numerous encapsulation methods. However, they always went through complicated preparing and processing steps. In this research, a novel nano-formulation of curcumin by wet-milling technology has been developed. A suspension of curcumin and modified starch was wet-milled to create a stable nanodispersion. Some of the suspension was spray dried. The other was freeze dried. Powdered samples were stored at 4°C in dark for storage. The average particle size of curcumin nanodispersion reduced from 2.4 µm to 150 nm after one-hour wet-milling process and increased to around 170nm after one-month storage. The solubility of the nano-sized curcumin was 8.8±0.3 mg/ml increased by 8x105-fold compared to the unformulated curcumin. DSC and XRD results revealed that wet-milling process with modified starch not only reduced the particle size to nano-range, but also transferred some degree of crystal curcumin into the amorphous state. Moreover, the formulated curcumin showed enhanced in-vitro anti-cancer activity in Human hepatocellular carcinoma cell line in the range of 0.5-10 ug/ml. Moreover, the difference of freeze-drying and spray-drying processes on the properties of nano-curcumin formulation was studied. Both DSC and XRD showed that the freeze-dried nano-curcumin powder had more degree of amorphous state than that of the spray-dried. Using Caco-2 cell monolayer model, it revealed that the permeation of the freeze-dried nano-curcumin was faster than that of the spray-dried one, which indicated that the amorphous form could provide the absorption advantage for the poor water soluble compounds. This new formulation provides a promising opportunity in the functional food market. Also wet milling technique can be applied for oral delivery systems of other poor-water-soluble compounds for functional food applications.

ETD_4796

M.S.

Includes bibliographical references

by Dong Liu

doi:10.7282/T3S75DCF

ETD graduate

The author owns the copyright to this work.