• Korean Journal of Food Science and Technology
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• v.51 no.6
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• pp.584-591
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• 2019

Of all the various types of tea that are available, Pu-erh tea has attracted much attention because of its healthpromoting effects. The objective of this study was to investigate the physicochemical and antioxidant properties of two types of Pu-erh tea, Gushu Pu-erh and typical Pu-erh, extracted at 80 and 100℃, respectively. The Gushu Pu-erh extracts showed lower pH but higher antioxidant potential at both the temperatures, as compared to the typical Pu-erh. The mineral content of the tea extracts was greater at 100℃ than at 80℃. Among the seven categories of the flavor compounds that were detected, the peak area of esters was the highest in the Gushu Pu-erh extracts. The type of tea and the extraction temperature significantly affected the physicochemical and functional properties of these tea extracts. This study revealed that Gushu Pu-erh extracted at 100℃ for 3 min with 30 s of shaking provides better results in terms of the antioxidant potential and mineral content.

• Journal of Environmental Science International
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• v.24 no.2
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• pp.189-196
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• 2015

This study was performed to identify the effect of mixed bed soil on growth of aerial parts and root zone of daughter plants for nursery field strawberry seedling raising with expanded chaff. The plant height and leaf area of daughter plants were highest or largest in the mixed soil of ERH +RH (100:0, v/v), followed by ERH+RH (75:25). The higher the mixing ratio of RH, the shorter the plant height or the smaller the leaf area. A similar tendency was observed in fresh weight. Within a root diameter of 0-0.4 mm and a root height range of 0.4-0.8 mm, root surface area and volume were statistically significantly better with treatment of ERH+RH (100:0, v/v) compared to those of roots treated with ERH+RH (75:25), ERH+RH (50:50) and ERH+RH (25:75). The growth rate of aerial parts and root zone of daughter plants were noticeably lower in two mixing ratios of 50:50 and 25:75. According to the mixing ratios of ERH+CD surface treatment, the number of roots was greatest in plants treated with ERH+CD (80:20, v/v) and ERH+CD (85:15) on August 1. However, the number of roots was highest in plants treated with ERH+CD (85:15, v/v) on August 15. Root length was longest in the plant with no treatment, and drastically shortened from ERH+CD (90:10, v/v) in both surface and mixed treatment. Although root weight showed a significant difference in ERH+CD (90:10, v/v) treatment, its increase was gradual. The rate of root growth was highest in ERH+CD (85:15). These study findings suggest that the content ratios of mixed soil ERH+RH (75:25, v/v) or below and ERH+CD (85:15) are thought to be desirable for the production of high quality seedlings.

• Biomedical Science Letters
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• v.29 no.2
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• pp.58-65
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• 2023

Pu-erh tea, a popular and traditional Chinese tea, possesses various health-promoting effects, including inhibiting tumor cell progression and preventing type II diabetes and neurodegenerative disorders. However, the precise anti-inflammatory mechanisms are not well understood. In present study, we elucidated the anti-inflammatory mechanism of Pu-erh tea in lipopolysaccharide (LPS)-activated RAW264.7 cells. We explored the effects of Pu-erh tea on the levels of inflammatory-related genes, including inducible nitric oxide synthase (iNOS), cyclooxygenase (COX)-2 and prostaglandin E₂ (PGE₂) in LPS-activated RAW264.7 cells. Moreover, we investigated its regulatory effects on nuclear factor-kappa B (NF)-κB and hypoxia-inducible-factor (HIF)-1α activation. The findings of this study demonstrated that Pu-erh tea inhibited the LPS-increased inflammatory cytokines and PGE₂ release, as well as COX-2 and iNOS expression. Moreover, we confirmed that the anti-inflammatory mechanism of Pu-erh tea occurs via the inhibition of NF-κB and HIF-1α activation. Conclusively, these findings provide experimental evidence that Pu-erh tea may be useful candidate in the treatment of inflammatory-related diseases.

• Horticultural Science & Technology
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• v.33 no.1
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• pp.47-54
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• 2015

This research was conducted to investigate the changes in moisture retention capacities of expanded rice-hull (ERH)-based root media and their influences on the growth of mother and daughter plants in vegetative propagation of 'Seolhyang' strawberry. The proportion of water at the container capacity of ERH medium was in the range of 20 to 23%. This range was lower than the 60 to 66% of strawberry-specialized medium, the 30 to 34% of soil mother material (SMM) and the 30 to 35% of loamy sand. The moisture content of ERH was reduced to 10 to 12% at 8 hours after irrigation, and there were large variations among replications of ERH medium. Among four kinds of root media formulated to contain ERH, the medium of ERH + coir dust (CD) (55 + 45%, v/v) had 26.5 and 32.5% water contents at 20 and 40 days after irrigation to daughter plants, respectively. The m edia o f ERH + sandy loam (S L) and E RH + S MM showed similar trends i n moisture r etention. The pH and EC i n the all root media tested were in the range of 6.7 to 7.1 and 0.03 to $0.08dS{\cdot}m^{-1}$, respectively. The pHs and ECs measured at 20 and 40 days after irrigation were not significantly different in each root medium. Among the root media formulated to contain ERH, the growth of daughter plants was the highest in the treatment of ERH + SL (55 + 45%, v/v). As the blending rate of coir dust was elevated in the ERH + CD media, moisture retention capacity increased gradually, but the growth of daughter plants became worse even though the medium showed higher moisture retention capacity than other root media tested. The growth of roots and aboveground tissues of daughter plants deteriorated in the root media formulated by blending ERH + perlite (PE) at various ratios. The results of this research suggest the optimum formulations of root media and management of moisture content in raising of strawberry daughter plants when ERH is a component of root media.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.164-170
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• 1999

Cracking of rice caused by moisture migration during storage under different relative humidity conditions was investigated for the establishment of safe storage condition of rice. Rice was cracked when a large difference in equilibrium relative humidity $({\Delta}ERH)$ between the rice and the environment was present. External and internal cracks were generated as the results of moisture desorption and adsorption, respectively. The external cracks by moisture desorption generated in all directions and shaped irregularly, while the internal cracks by moisture adsorption did in radial direction and showed a typical shape. The cracking trend could be analyzed by the Weibull function, and the cracking constant increased with ${\Delta}ERH$. The frequency of cracked rice increased linearly with In $({\Delta}ERH)$. The critical crack-inducing ${\Delta}ERH$ was $11.3{\sim}16.4%$ during desorption and $10.8{\sim}17.1%$ during adsorption. A diagram for the safe storage of rice was developed with respect to the initial moisture content and the water activity of rice.

• Horticultural Science & Technology
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• v.32 no.2
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• pp.157-164
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• 2014

Objective of this research was to develop root media containing expanded rice hull (ERH) and carbonized rice hull (CRH). To achieve this, the physico chemical properties of two materials were analysed and blended with peatmoss (PM) or coir dust (CD) with various ratio. Based on the physical properties of the blended materials, 4 root media were selected for future experiment. After the analysis of pH and EC of the selected root media, the kinds and amount of pre-planting nutrient charge fertilizers (PNCF) incorporated into each root medium were varied, and then, final chemical properties of the root media were analysed. The total porosity (TP), container capacity (CC), and air-filled porosity (AFP) were 81.3%. 39.9%, and 41.4% in ERH and 77.6%, 64.1%, and 13.5% in CRH, respectively. The percentage of easily available water (EAW, from CC to 4.90 kPa tension) and buffering water (BW, 4.91-9.81 kPa tension) were 11.37% and 5.27%, in ERH and 17.26% and 14.28% in CRH, respectively. The pH of ERH was 7.1, but it was extremely high in CRH such as 11.2. The EC and CEC were $1.31dS{\cdot}m^{-1}$ and $12.1meq{\cdot}100g^{-1}$ in ERH and $6.53dS{\cdot}m^{-1}$ and CEC 7.79 $meq{\cdot}100g^{-1}$ in CRH, respectively. The ranges of TP, CC and AFP in 4 selected media (PM + ERH, 6:4, v/v; CD + ERH, 8:2; PM + CRH, 7:3; CD+CRH 6:4) were 89.2-90.3%, 67.3-81.8%, and 8.3-21.9%, respectively. The pHs and ECs in root media containing peatmoss such as PM + ERH (6:4) and PM + CRH (7:3) were 4.0-4.3 and $0.33-0.365dS{\cdot}m^{-1}$, whereas those of CD + CRH were 7.4-7.9 and $1.282dS{\cdot}m^{-1}$. The pHs and ECs, however, analysed before and after the incorporation of PNCF in each root medium were not significant different. This result indicated that the incorporated fertilizers in PNCF to adjust medium pH did not dissolve enough to influence medium pH, but it is very normal in root media containing dolomitic lime and sulfur powder in adjusting pH. The Information obtained in this study may facilitate an effective formulation of root media containing rice hulls.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.1
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• pp.55-59
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• 2005

Rice farmers can save labor and expenses by using expanded rice husk (ERH) as a seedling medium since ERH is lighter and cheaper than other commercial seedling media (CSM). This study was carried out to develop a method for rice seedling cultivation using ERH as a seedling medium. It is suggested that a mixture of $60\%$ of ERH and $40\%$ of a CSM could be used as a seedling medium; the planting densities would be 240g per tray for infant seedlings and 200 g for young seedlings; and nitrogen (N) would be applied at a rate of 1g per tray for infant seedlings prior to planting and 2g per tray for young seedlings with division. Great care should be taken to use $CO(NH_2)_2$ as an N-source fertilizer. These results would lay a foundation for the rice seedling cultivation with ERH as a medium.

• Journal of Biosystems Engineering
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• v.30 no.2 s.109
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• pp.95-101
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• 2005

Adsorption and desorption experiments were carried out on rough rice and brown rice (Nampyung) at 5, 15, 25, 35, $45^{\circ}C$ for moisture contents between 8.7 and $25\%$ (db). The method employed was to measure the equilibrium relative humidity (ERH) of air in contact with the grain under static conditions, using an electronic hygrometer The effects of temperature and moisture contents were investigated, and the measured values were fitted to the modified Henderson, the modified Chung-Pfost, the modified Halsey and the modified Oswin model. The ERHs of rough rice and brown rice decreased with an decrease in moisture content and temperature, and the effects of temperature was no significant at moisture content of $25\%$ (db). Equilibrium moisture content (EMC) of brown rice was higher than rough rice at same temperature and relative humidity. Desorption EMC is higher than the adsorption, but there is no significant difference between desorption and adsorption EMC in moisture content near $25\%$ (db) at rough rice and near 9, 21 and $25\%$ (db) at brown rice. The modified Oswin model was the best in describing the adsorption EMC and the modified Chung-Pfost model was the best in describing the adsorption ERH of rough rice. The modified Oswin model was the best in describing the adsorption EMC/ERH of brown rice. The modified Chung-Pfost model was the best in describing the desorption EMC/ERH of rough rice and brown rice.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7389-7394
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• 2014

Background: Chemotherapy is one of the major means for control of malignancies, with cisplatin (CDDP) as one of the main agents, widely used for the treatment of various malignant solid tumors. However, prevention of hepatotoxicity from cisplatin is one of the urgent issues in cancer chemotherapy. In this study, we aimed to investigate the effects of pu-erh tea on hepatotoxicity through body weight and tissue antioxidant parameters like, liver coefficient, serum alanine aminotransferase (ALT), serum aspartate aminotransferase (AST), superoxide dismutase (SOD), glutathione peroxidase (GSH-PX), malondialdehyde(MDA) and glutathione (GSH) levels, and light microscopic evaluation by histological findings. Materials and Methods: The rats were randomly divided into five groups: Control (n=10), cisplatin (3 mg/kg p.i., n=10), cisplatin+pu-erh (0.32 g/kg/day i.g., n=10), cisplatin+pu-erh (0.8 g/kg/day i.g., n=10) and cisplatin+pu-erh (1.6 g/kg/day i.g., n=10). Pu-erh tea powder was administrated for 31 consecutive days. The rats were sacrificed at the end on the second day after a single dose of cisplatin treatment for measuring indices. Results: Pu-erh tea powder exhibited a protective effect by decreasing MDA and GSH and increasing the SOD and GSH-PX levels and GSH-PX/MDA ratio in camparison with the control group. Besides, pu-erh tea was also able to alleviate the pathological damage to some extent. Conclusion: Pu-erh tea powder is protective against cisplatin-induced liver oxidative damages, especially at the medium dosage (0.8 g/kg/d).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.3
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• pp.179-183
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• 2003

In comparison of physicochemical properties between expanded rice hulls (ERH) and a commercial nursery soil (Bunong), the pH and content of organic matters were higher in ERH than those of Bunong soil. However, the content of available phosphate, $\textrm{NH}_4\textrm{-N}$ and $\textrm{NO}_3\textrm{-N}$ were lower in ERH as compared with Bunong soil. The growth characteristics of seedlings were evaluated for 15-day old seedlings grown in five different nursery soils including ERH. The plant height was the tallest (22.8cm) in Bunong soil and shortest (12.8cm) in ERH. There was no difference in number of leaves among five types of nursery soils. The best results based on the seedling quality and root intensity was obtained from the seedlings grown in the nursery soil which ERH was used for bedding and Bunong soil for covering in the seed tray. The weight of a seed tray with Bunong soils was 27% heavier than that of 'ERH + Bunong soil'.