The major active components of Astragalus membranaceus (AM) are isoflavones, which exist in the form of various glycosides. Nuruk is a traditional fermentation starter in Korea, and is suitable for the biotransformation of isoflavone glycosides because it contains various microorganisms and enzymes. This study was performed to determine changes in the isoflavones and antioxidant properties of AM fermented (AF) with nuruk over 24 hours. AF was sampled after 0, 2, 4, 6, 12, 18, and 24 h of fermentation, and calycosin 7-glucoside, ononin, calycosin, and formononetin content, and the antioxidant properties of AF were analyzed. The total phenolic content increased with fermentation time, and the ABTS radical scavenging activity increased until 6 h of fermentation and then decreased. During fermentation, the isoflavone glycosides decreased significantly as fermentation time increased. The contents of calycosin and formononetin, which are aglycons of calycosin-7-glucoside and ononin, increased from 100.54 μg/g to 276.84 μg/g and from 56.29 μg/g to 123.04 μg/g, respectively, at 18 h of fermentation. Significant correlations were observed between fermentation time, isoflavone content, and antioxidant properties. The results of this study showed that fermentation with nuruk is suitable for the biotransformation of isoflavones in AM.

Aster koraiensis Nakai (A. koraiensis) which has been used as a food and medicinal plant in the past, is valuable as functional food material. Therefore, the aim of this study was to determine the antioxidant properties and major phenolics of A. koraiensis extracts with different ethanol concentrations (0, 50, 70, and 100% aqueous ethanol solution). When ethanol concentration in the extraction solvent was increased, extraction yield decreased; 34.2, 23.2, 21.0, and 5.5% in 0, 50, 70, and 100% ethanolic extracts, respectively. Total phenolics content and antioxidant activities of extracts were increased in an ethanol concentration-dependant manner. The major phenolics in the extracts were chlorogenic acid (21.264~58.666 mg/g), isochlorogenic acid A (10.432~145.353 mg/g), and isochlorogenic acid C(0.239~13.148 mg/g), and these phenolic contents were higher in 70 and 100% ethanolic extracts than other extracts. Significant correlations were observed between ethanol concentration of extraction solvent, antioxidant properties, and major phenolics. These results indicated that the optimal ethanol concentration for extraction was 70%.

Fresh Omija (Schisandra chinensis) has good marketability, but its quality is difficult to maintain during storage and distribution. Freezing and freeze-thawing treatments can be utilized for the quality maintenance and processing of cold press juice. In this study, the color, antioxidant properties, and the major components of soaked liquor from Omija with freeze-thawing treatment were analyzed during the extraction periods. Each of the frozen and freeze-thawed Omija samples was soaked in 35% ethanol, extracted for 15 days, and used for analysis. The frozen and freeze-thawed samples showed a tendency toward better color and higher antioxidant activity and major component levels than the controls, and freeze-thawing was the best. The results of this study showed that freeze-thawing treatment improved the color, antioxidant properties, and level of the major components of Omija soaked liquor, and freeze storage is suitable for making soaked liquor.

Angelica gigas Nakai (A. gigas) easily changes its color during storage, and appropriate thermal treatment can improve storage stability through inactivation of enzymes such as polyphenol oxidase. Therefore, this study was performed to determine quality characteristics of dried A. gigas in response to high-temperature-short-time (HTST) treatment during storage. Dried A. gigas were treated at 120-180℃ for 10 min, the samples were stored at 4℃ and 50℃ for 10 weeks, and used for the analysis of qualities. Concerning the color values, the sample treated at 120℃ was similar to the control, and the color change was large when treated above 180℃. However, color difference (△E* ab) was lower in treated samples than in control. Browning index was similar for all the samples except for the sample treated at 180℃. Functional qualities (phenolics content, antioxidant activities, and level of major components) showed a slight difference according to storage periods in all samples without control, and nodakenin content was observed in control. The results of this study showed that HTST treatment improved storage stability such as stability of colors and browning index in dried A. gigas during storage, and the appropriate treatment temperature was 120℃ in terms of stability in color and browning index.

The aging treatment was applied to Rehmannia glutinosa rhizome (RGR) to improve the digestibility by the enzymatic hydrolysis of undigestible sugars. However, RGR spoils easily during the aging treatment. Thus, the purpose of this study was to investigate the influence of ethanol addition as preservatives on sugars and microbial growth of aged RGR. The RGR was treated with the addition of ethanol (0~10%) at 55℃ for eight days. Reducing, free sugars, and total bacterial counts of RGR with ethanol concentrations were analyzed during the aging periods. The aged RGR with 0-2% ethanol appeared spoiled in appearance, and total bacterial counts of these samples increased from 1.1×105 to 2.2×107 CFU and then decreased again. When treated with 4~10% ethanol, the total bacterial counts of aged RGR decreased by more than 99.9% at eight days. In all samples, reducing and digestible sugars increased, and stachyose decreased by the aging treatment. Sucrose content was highest in the 6% ethanol sample (18.2% at six days). These results indicate that the ethanol addition can be applied to the aging treatment of the RGR for improving qualities (sweetness, digestibility, and microbial growth), and can be considered for the stable production of high quality aged RGR.

본 연구는 환경친화적인 중금속 정화방법인 식물복원법(phytoremediation)의 적합성 규명을 위해 미적 가치를 제공할 수 있는 조경식물로 코스모스와 해바라기를 이용하였고, Cu와 Cd의 중금속을 농도별로 처리하여 생육량과 생리적 특성을 조사하였고, 식물체내의 중금속 축적량을 확인하여 식물복원법 적용의 타당성을 제안하고자 실시하였다.농도별 중금속 처리에 있어서 그 처리 농도가 높을수록 생육량이 불량하였고 엽록소 함량은 대조구에 비해 Cu처리에서 다소 높았고 Cu 처리농도가 높을수록 증가하였으며 Cd 처리에 있어서는 그 함량이 감소하였다. 수용성 단백질 함량은 저농도의 중금속 처리에서는 대조구와 큰 차이가 없었지만 Cu 2000μM과 Cd 100μM에서 그 함량이 감소하였다. 전질소 함량은 Cu 2000μM에서 가장 저조하였고, 엽록소와 수용성 단백질과는 달리 생육기간이 경과할 수록 그 함량이 감소되는 경향을 보였다. 중금속의 처리 농도가 증가할수록 생육량과 생리적 양상에서 다소 저해를 보였지만 축적량이 증가하는 경향을 보였고, 지상부에 비해 지하부의 축적량이 많았으며 식물체내의 중금속 축적량은 코스모스는 뿌리에서 Cu 453.44μg/g, Cd 675.14μg/g이었고, 해바라기는 뿌리에서 Cu 353.14μg/g, Cd 140.76μg/g으로 그 축적량이 양호하였다. 따라서 코스모스와 해바라기는 경관조성이 가능한 phytoremediator로서의 가능성이 있을 것이라 생각된다.