Studies on the Functional Hydrogel Beads of Burdock Leaf Extracts and the Evaluation of in vitro Release Control

• Main Authors: Fu-Hsuan Tsai, 蔡馥亘
• Other Authors: Po-Yuan Chiang
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/8rmugz

碩士 === 國立中興大學 === 食品暨應用生物科技學系所 === 100 === Burdock contains abundant dietary fiber and nutrient is widely preferred by medicine, health care, and consumer. Burdock’s production is keeping increasing recently. Burdock leaf is the waste after harvesting the burdock root. It contains abundant chlorogenic acid and phenolic compounds and becomes a popular material for research. This study firstly searchs the optimized extraction conditions of burdock leaf and analyze extract’s functional compounds and antioxidant ability. Furthermore, we use loading efficiency, hardness, swelling capacity, and outer appearance to evaluate functional hydrogel beads of burdock leaf extracts’s optimized preparation conditions. And then, we evaluate the effect of thermal treatments and simulated gastrointestinal fluids on the physicochemical properities and release profiles of hydrogel beads. Finally, we analyze the effects of blanching and micronization on the physicochemical properities, functional compounds and antioxidant ability of burdock root. This research results showed that the optimized extraction conditions of burdock leaf were solid to liquid 1:3 with 95 % EtOH at 80℃ for 90 min, and we could obtain 38.73 mg/g dw total phenolic compounds, 8.56 mg/g dw total flavonoid, and 23.81 mg/g dw chlorogenic acids; the reducing power and DPPH scavenging activity were 2.622 and 59.49 %, respectively. The optimized preparation conditions of functional hydrogel beads of burdock leaf extracts were 1.0 % sodium alginate, 30 min for first curing, and 0.5 % CaCl2 for second curing, the functional hydrogel beads of burdock leaf extracts’s loading efficiency was 825.71 %, swelling capacity was 11.90 %, particle size was 2.79 mm, and hardness was 666.32 g. The hardness of functional hydrogel beads of burdock leaf extracts decreased after thermal treatments, and swelling capacity increased significantly. The chlorogenic acid release profile of functional hydrogel beads of burdock leaf extracts which without curing conformed to zero-order kinetics model (r2=0.990~0.993), and the curing one conformed to Higuchi kinetics model (r2=0.899~0.980). The swelling capacity of functional hydrogel beads of burdock leaf extracts decreased in simulated gastric fluids and increased in simulated intestinal fluids. We evaluated the release profile by Korsmeyer-Peppas model and the release exponents were about 0.143~0.255. Peroxdiase of burdock root could reduce 90 % after blanching at 98±2℃ for 6 min. Along with the decrease in particle size of blanched burdock, the bulk density and cation-exchange capacity had a tendency of increasing; the oil-holding capacity was a decrease; and there were first an increase followed by a decrease in the swelling capacity and oil-holding capacity. The dietary fiber, inulin, and chlorogenic acid content of burdock root powder was 47.41 g/100 g dw, 201.13 mg/g dw, and 2.03 mg/g dw, respectively.