Seung Mi Kim

Physicochemical Characteristics and Antioxidant Capacity of Rice Cake (Sulgitteok) Supplemented with Lyophilized Sedum sarmentosum (Dolnamul) Powder

This study was performed to increase the availability of Sedum sarmentosum (Dolnamul) and to improve the nutraceutical value of rice cakes (sulgitteok). The contents of crude protein, mineral, dietary fiber, water holding capacity, and hardness significantly and directly increased with lyophilized sedum powder (SP). Pore ratio and expansion rate decreased in samples containing more than 10% SP compared to the control. In a sensory evaluation, a positive correlation was detected between overall acceptability and taste (R2=0.99, p<0.01), and color (R2=0.72, p<0.05). Total polyphenol contents of the SP-treated groups were significantly elevated, accompanied by an increase in radical scavenging ability estimated by the 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. Replacing 10% of the rice powder with SP efficiently improved the antioxidant and nutritional values of sulgitteok as well as its the sensory quality.

Identification of D-Friedoolean-13-en-3-one (Taraxerone) as an Antioxidant Compound from Sedom (Sedum sarmentosum)

A pentacyclic triterpenoid compound was isolated from the ethyl acetate extract of sedum (Sedum sarmentosum) and identified as d-friedoolean-13-en-3-one (taraxerone) by GC-MS and crystallographic analysis. The extraction yield of taraxerone was 74.12±0.57 mg/kg sedum (dry weight). The IC50 values of taraxerone were 102.34±1.53 μM and 1,763.81±12.63 μM/mL (Trolox equivalent) by the DPPH and ferric reducing ability of plasma (FRAP) assays, respectively. Taraxerone exhibited comparable antioxidant capacities with butylated hydroxytoluene (BHT) by the DPPH (p=0.117) and FRAP (p= 0.179) assays. The production of inducible nitric oxide in lipopolysaccharide-stimulated murine macrophage was inhibited by taraxerone (IC50=38.49±3.77 μM) via downregulation of inducible nitric oxide synthase (iNOS) expression at the transcriptional level. The inhibitory effect of taraxerone on nitric oxide generation was significantly more effective than that of caffeic acid and/or gallic acid.

Quality Characteristics of Dinner Roll Added with Lyophilized Sweet Potato Powder and Its Effect on the Blood Glucose Level

The present study was performed to increase the availability of sweet (Ipomoea batatas) and to develop dinner roll with the reducing ability of blood glucose levels. Different contents of lyophilized sweet potato powder (SPP) were added in dinner roll. Compare to the control group, batter density, a value, hardness, and cohesiveness of the SPP-treated groups were significantly increased while dough expansion rate, baking loss rate, L value, and Hue angle were significantly decreased. Twenty four Sprague-Dawley rats were administered with the SPP-treated diet for 4 weeks after diabetes was induced with the injection of streptozotocin. The blood glucose concentration of the SPP-treated group was significantly lower than that of the control. Although the SPP-treated groups possessed the ability of reducing blood glucose level, the sensory qualities were inferior to the control. Thus, follow-up study was required to improve the sensory characteristics as well as the texture properties.