Chung-Jo Lee

Inhibitory Effect of Ecklonia cava Extracts against Lipase Activity and Stability Effect of Temperature and pH on Their Activity

This study was performed to investigate the inhibitory activity of Ecklonia cava (EC) against lipase and the stability of this activity under various heat and pH conditions. As a result, EC ethanol extract showed lipase inhibitory activity of 59, 34 and 19% at concentrations of 5, 2.5 and 1 mg/mL, whereas the water extract showed low inhibitory activity at all concentrations compared to that of the ethanol extracts. In a heat and pH stability test, the inhibitory activity of the EC ethanol extract increased with heat treatment at for 15 min compared with the control and was stable in the pH range of 2~10. Therefore, the EC ethanol extract could be useful as a natural anti-obesity agent.

Effects of Autoclave and Microwave Treatments on the Antigenicity of Gliadin in Medium Wheat Dough

The aim of this study was to determine the optimal physical treatment to reduce the antigenicity of gliadin in wheat dough. Medium wheat dough was treated with an autoclave (5, 10, 30, and 50 min at 121 o C, 1 atm), a microwave (1, 5, and 10 min) or both (10, 30, and 50 min/5, 10 min). The proteins in the dough extracts were analyzed by SDS- PAGE and the binding ability of anti-gliadin IgG to gliadin was examined by ci-ELISA and immunoblotting. Results showed that the ability of anti-gliadin IgG to bind to gliadin in wheat dough treated with an autoclave alone or in combination with a microwave was decreased. Especially, it declined to ~77% after autoclaving for 30 min and 35% after both autoclaving for 50 min and microwaving for 5 min. In addition, the intensity of gliadin bands in SDS-PAGE were weakened and anti-gliadin IgG did not recognize gliadin in immunoblotting. However, microwaving alone did not affect the antigenicity of gliadin in wheat dough. These results indicate that autoclaving may affect the reduction of the antigenicity of gliadin in medium wheat dough. Moreover, autoclaving in combination with microwaving is more effective for reducing the antigenicity of wheat dough.

Effect of Sargassum fulvellum Extracts on Shelf-Life and Quality Improvement of Bread

This study was performed the effect of Sargassum fulvellum extracts (SFE) on the shelf-life and quality improvement of bread. Bread was added with 0.5, 1 and 2% SFE and stored for 9 days. Total microbial counts of the bread added with 1 and 2% SFE were reduced by 2 log cycles at 9 days, and there were no significant changes in pH value or moisture content compared to the control. In addition, the protection factor of the bread added SFE measured by Rancimat showed a higher level than that of the control. Yellowness increased as bread was added with SFE while lightness and redness decreased. Springiness showed no considerable differences between the control and the group added with SFE. Hardness, shear force, gumminess and chewiness were higher than those of the control. In the sensory evaluation, right after manufacturing, taste, texture, and total preference of the bread containing 0.5 and 1% SFE were preferred compared to the control. These results suggest that the addition of 0.5% and 1% SFE to bread enhance the quality and shelf-life of bread.

Effect of Sargassum sagamianum Extract on Shelf-life and Improved Quality of Morning Bread

This study was performed to test the effect of Sargassum sagamianum extract (SSE) on shelf-life and improved quality in bread with 0.25, 0.5 and 0.75% added SSE. Bread with added SSE had reduced total microbial counts by 2 log cycles and mold cell counts by 3 log cycles. No changes in moisture content or pH occurred from days 3 to 9. In addition, bread with SSE had a lower yield of malonaldehyde than that of the control as shown by the TBARS assay. Yellowness increased in bread with added SSE, whereas lightness and redness decreased. In the sensory evaluation, taste, total preference, inner shape, and color of the bread containing 0.25 and 0.5% SSE were preferred. These results suggest that the adding 0.25 and 0.5% SSE to bread improved shelf-life and quality.

Effects of Heat and pH Treatments on α-Amylase Inhibitory Activity of Ecklonia cava Ethanol Extract

This study examined the inhibitory activity of Ecklonia cava (EC) against α-amylase to evaluate the availability of EC extract as a functional food agent. To verify the inhibitory activity of EC against porcine pancreatic α-amylase, potato starch was used as a substrate. This analysis revealed that EC ethanol extract exhibited high α-amylase inhibi-tory activity. For potential application within the food industry, the stability of the activity of EC ethanol extract under various heat and pH conditions was examined. The α-amylase inhibitory activity of EC ethanol extract was not af-fected by the heat and pH treatment conditions used in this study. These results suggest that EC has the potential for development as a functional food agent.Key words: Ecklonia cava, Ethanol extract, α-Amylase inhibitor, Functional food agent