| Summary: | 碩士 === 國立臺灣大學 === 食品科技研究所 === 106 === Sweet potato (Ipomoea batatas L.) leaves, a common vegetable in Taiwan, are rich in dietary fiber, minerals, antioxidants and other bioactive compounds. According to National Food Consumption Database, sweet potato leaves are important sources for antioxidant components obtaining from fruits and vegetables. Sweet potato leaves are rich in lutein which are associated with preventing eye diseases such as age-related macular degeneration (AMD) and cataracts. In leafy vegetables, lutein is present in the cell wall, formed a complex with protein which can be released by heating or fine grinding. Media milling can reduce the particle size distribution into the sub-micron scale, 0.1 to 1 μm, facilitating the release of bioactive compounds and the increase of bioavailability. In this study, we explored the effects on physicochemical properties and the content of lutein, total carotenoid of different varieties and drying conditions sweet potato leaves using media-milling process. Biodistribution of lutein was evaluated using Wistar rats as animal models by analyzing the lutein content of plasma and liver after administering lutein-containing sweet potato suspension for four weeks. The results showed that the volume-mean diameter of sweet potato suspension particle decreased sharply from 56 ~ 117.77 m to 7 ~ 27 m, and the percentage of particle smaller than submicron (<1 m) was 99.9% after two hours milling. The zetapotential were higher than 30 mV or lower than -30 mV, indicating the high stability of the suspensions were obtained. The pH values of suspensions were ranged 5.1 ~ 5.86, which were weak acidity. The viscosity of suspensions were reached the highest value after media-milled for 90 minutes. The viscosity of media-milled suspensions (3357 to 12410 cP) were 8 folds higher than without media-milled suspensions (994 ~ 3732 cP). With the increase of milling time, the color of suspensions were tended to yellowish green. The lutein content and total carotenoid content of freeze-dried group were higher than that of cool-dry. The lutein content of CYY98-63 (purple leaf varieties) was the highest (0.84 ~ 0.97 mg per gram dry basis). Biodistribution results showed that the lutein content in liver of lutein intervention group was higher than that of control group without intervention of lutein.
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