Hsi-Mei Lai has completed her PhD from University of Illinois at Champaign and Urbana in 1990. She worked in China Grain Product Research and Development Institute,Taiwan as a Research Fellow for six years. Currently, she is the Professor and Head of Department of Agricultural Chemistry at National Taiwn University in Taipei, Taiwan. Her researches focus on the studies of biopolymers’ properties and applications on the environmental friendly responsive (nano) materials for foods and pharmaceuticals. She has published more than 50 papers in reputed journals and serving as Editorial Board of Journal of Food and Drug Analysis. She is the President of Agricultural Chemistry Society of Taiwan.
The spherical particles of cationic starch (CS) microgels could be prepared by partially gelatinizing the CS granules followed by stabilizing the swollen particles with cross linkers sodium trimetaphosphate (STMP). The desirable partial gelatinization process and the degree of STMP crosslinking was determined by using a rhenometer equipped with a Couette fixture and thermal gravimetric analysis (TGA), respectively. Swelling/de-swelling behavior of CS microgels responsive to various pH and ionic strength conditions were evaluated from several aspects of physical properties, including particle size distribution, swelling ratio and rheological properties. It is found that the partial gelatinization process (50°C, 10 min) could keep the most of CS swollen granules intact. STMP in CS microgel behaved as ionic and chemical crosslinkers, which were saturated at STMP/CS weight ratio of 0.2. The swelling behavior of CS microgels was dominated not only by the STMP crosslinking, but also by the excess cationic groups of CS, which were sensitive to the environmental salt concentration and pH. The rheological properties indicated that the excellent water uptaking ability of CS microgels raised their viscosity, which might undergo de-swelling at high salt concentration due to the highly deformable characters of CS microgels.
Be-Jen Wang has completed her PhD from Cornell University. She was an Associate Professor in China Medical University from 1992 to 1995. Since 1995, she is working as Professor of National Chiayi University. Her research concentrates on Food Science and Nutrition. She has published more than 40 papers in reputed journals and 12 related patents in Food Science and Technology.
Ethanol extract (E) of rice bran was fractionated by supercritical CO2 fluid system into four fractions (R, F1, F2, and F3) at 45o C and pressures of 30, 25, 20, and 15 MPa, respectively. This study aimed to evaluate the distribution of antioxidant compounds (γ-oryzanol, ferulic acid, and phenolic compounds) and antioxidant activities of supercritical CO2 fractions. Results showed that the contents of γ-oryzanol and ferulic acid in different fractions were in the order of F > E > R; while the highest amount of phenolics was detected in R. E exerted the strongest 2,2-diphenylpicrylhydrazyl (DPPH) and ABTS radicals scavenging activities. The contents of total phenolic compounds, γ-oryzanol and ferulic acid in fractions were significantly positive correlated with the antioxidant capacities. Linear structural models analysis showed that although the correlation between antioxidant components is high, the scavenging activities of both free radicals mainly related to total phenolic compounds.