• Food Science and Biotechnology
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• v.17 no.6
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• pp.1387-1390
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• 2008

This study evaluated the effects of heat treatment on antioxidant activity of Rehmannia radix Libosch (RRL). RRL was heated at various temperatures ($110-150^{\circ}C$) for various times (1-5 hr), and the total polyphenol, flavonoid content, and antioxidant activity were investigated. With increased heating temperature and exposure time, total content of polyphenol, flavonoid, as well as antioxidant activity increased. The highest total polyphenol and flavonoid contents were 21.65 and 3.56 mg/g, respectively, these values were occurred after heating for 3 hr at $150^{\circ}C$ (RRL was 5.09 and 0.83 mg/g, respectively). The 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity was highest value of 83.46% after heating for 3hr at $150^{\circ}C$. The 2,2-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS) cation radical scavenging activity was highest value of 20.43mg ascorbic acid (AA) eq/g after heating for 2 hr at $150^{\circ}C$. There were highly significant differences in the total polyphenol, flavonoid content, and antioxidant activity among heating temperatures and times (p<0.001), with heating temperature having the greater effect.

• Korean Journal of Oriental Medicine
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• v.4 no.1 s.4
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• pp.115-127
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• 1998

To improve the quality control of frequently used oriental medicinal plants, the storage, cutting, processing and decokting methods of Rehmannia glutinosa Libosch. var. purpurea Makino(熟地黃) were examined. The contents of 5-hydroxymethyl-2- furaldehyde(5-HMF) of Rehmannia glutinosa Libosch. var. purpurea Makino were analysed by HPLC at various conditions as the standard component. Raw materials were classified into 3 groups with their specific gravity(天 地 人黃) and determined the ding weights and the contents of water, the solid component of Ji-Hwang(地黃) was the most. Rehmannia glutinosa Libosch. var purpurea Makino was steamed and dried nine times and analysed the content of 5-HMF on every time. In the case of Ji-Hwang, the standard component of the ninth sample was produced the most. But which of the tenth samples of Chun-Hwang and Yin-Hwang(天黃 人黃) were the most. The best decokting conditions which were determined by the yield of 5-HMF were as follows : non cutting, soaking time was 0 minutes, decokting time was 75 minutes after boiling. The contents of sugar on each of samples were determined. The contents of standard component increased by steaming number and the contents of sugar decreased.

• The Journal of Korean Medicine
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• v.23 no.2
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• pp.78-87
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• 2002

Objectives : The aim of this study was to investigate the effects of Ginseng Radix (Panax ginseng C.A. MEY.), Zizyphi Spinosae Semen (Zizyphus spinosa HU.) and Rehmanniae Radix Preparat (Rehmannia glutinosa LIBOSCH.) on the serotonin- immunoreactivity cells in the Caudal raphe nuclei, Rostal raphe nuclei and hippocampus of the mouse brain. Methods : The mice were stressed by restraining for one hour and treated with herbal medicine by oral feeding. The mice were killed after one hour and observed by electron microscope after immunohistochemical staining. Results : In the caudal raphe nuclei of the medulla oblongata, the highest number of 5-HT immunoreactivity cells were observed at the Zizyphi Spinosae Semen-treated group, while the lowest level among the herbs treatment group was shown at the Ginseng Radix group. In the hippocampus, serotonin-immunoreactive cells were expressed significantly at the CA3 area while the lowest level of it was shown at the control group. In the midbrain, immunoreactive cells were expressed higher than other groups, while observed at the lowest level in the control group. Conclusions : The extracts of Zizyphi Spinosae Semen, Rehmanniae Radix Preparat and Ginseng Radix show a certain degree of effect on the change of serotonin immunoreactive neurons as an index of nerve disorder.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.11
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• pp.1518-1524
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• 2011

This study was investigated the quality characteristics and antioxidant activities of the Rehmanniae radix (Rehmannia glutinosa Libosch. var. purpurea Makino) paste (RRP) and Rehmanniae radix preparata extract (RRPP). RRP and RRPP were made from vacuum concentrates of hot water extracts. The sugar contents of RRP and RRPP were 65.3 and 72.0$^{\circ}Brix$, respectively, whereas the reducing sugar contents were 2.4% and 44.9%. The pH level was lowest in the RRPP. The DPPH and hydroxyl radical scavenging activity of RRPP were much higher than those of RRP. Total phenol contents of RRP and RRPP were 2.15 mg/mL and 12.36 mg/mL, respectively. FRAP values of RRP and RRPP were 0.55 mg/mL and 2.02 mg/mL, respectively. Based on these results, it can be concluded that RRPP was the most appropriate in terms of both physicochemical and antioxidative activities.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.1
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• pp.62-67
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• 2013

This study was carried out to investigate the quality characteristics and antioxidant activities of Rehmanniae radix (Rehmannia glutinosa Libosch. var. purpurea Makino) freeze-dried powder (RRP) and Rehmanniae radix preparata powder (RRPP). Under the Hunter color system, redness was higher and lightness/yellowness lower in RRPP, compared to RRP. The reducing sugar contents of RRP and RRPP were 0.8% and 6.0%, respectively (p<0.05). The pH was lower in the RRPP (RRP: 6.71, RRPP: 4.23). The amount of catalpol amount in RRPP (47.20 mg/mL) was lower than RRP (144.90 mg/mL). RRPP contained high amounts of 5-HMF (5-hydroxymethyl-2-furaldehyde, 47,231 mg/mL), but 5-HMF was not detected in RRP. Total phenol contents of RRP and RRPP were 2.10 mg/mL and 3.66 mg/mL, respectively. FRAP values of RRP and RRPP were 0.51 mg/mL and 1.99 mg/mL, respectively. The antioxidant activities by DPPH (1,1-diphenyl-2-picryl hydrazyl) and hydroxyl radical scavenging activity of RRPP were much higher than RRP. Based on these results, RRPP is a good candidate for food processing in terms for its physicochemical and antioxidative activities.