• Korean Journal of Microbiology
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• v.27 no.2
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• pp.130-138
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• 1989

Microbiological parameters such as bacterial biovolume and biomass in Soyang Reservoir was statistically analyzed with the physico-chemical enviromental factors. Analysis of correlation and multiple regression showed that temperature affects most of microbiological parameters. Variations of total bacterial number, total bacterial biovolume and saprophyte number were highly correlatd with the concentrations of chlorophyll a and pheophytin a. Bacterial production by the $^{3}H$-thymidine incorporation rate was largely affected by Seston. It suggests that microbiological factors such as bacterial biovolume and bacterial biomass were controled by the concentration of seston and distribution of phytoplankton which acts as carbon and energy source for the bacterial community in the water column of Soyang Reservoir.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.6
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• pp.659-664
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• 2013

The aim of this study is to determine the drought stress index through photochemical analysis in red pepper (Capsiumannuum L.). The photochemical interpretation was performed in the basis of the relation between Kautsky effect and Photosystem II (PSII) following the measurement of chlorophyll, pheophytin contents, and $CO_2$ assimilation in drought stressed 5-week-old red pepper plants. The $CO_2$ assimilation rate was severely lowered with almost 77% reduction of chlorophyll and pheophytin contents at four days after non-irrigation. It was clearly observed that the chlorophyll fluorescence intensity rose from a minimum level (the O level), in less than one second, to a maximum level (the P-level) via two intermediate steps labeled J and I (OJIP process). Drought factor index (DFI) was also calculated using measured OJIP parameters. The DFI was -0.22, meaning not only the initial inhibition of PSII but also sequential inhibition of PSI. In real, most of all photochemical parameters such as quantum yield of the electron transport flux from Quinone A ($Q_A$) to Quinone B ($Q_B$), quantum yield of the electron transport flux until the PSI electron acceptors, quantum yield of the electron transport flux until the PSI electron acceptors, average absorbed photon flux per PSII reaction center, and electron transport flux until PSI acceptors per cross section were profoundly reduced except number of QA reducing reaction centers (RCs) per PSII antenna chlorophyll (RC/ABS). It was illuminated that at least 6 parameters related with quantum yield/efficiency and specific energy fluxes (per active PSII RC) could be applied to be used as the drought stress index. Furthermore, in the combination of parameters, driving forces (DF) for photochemical activity could be deduced from the performance index (PI) for energy conservation from photons absorbed by PSII antenna until the reduction of PSI acceptors. In conclusion, photochemical responses and their related parameters can be used as physiological DFI.

• Journal of the East Asian Society of Dietary Life
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• v.13 no.6
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• pp.586-592
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• 2003

This research used High Performance Liquid Chromatography(HPLC) to analyze and compare the content and the pattern of chlorophyll to find the difference in quality, water temperature, and the stirring time between the three different types of Korean and Japanese powder green tea, which were currently on the market. Chlorophyll contents of Japanese-made medium quality tea (S5: 8.34mg/g), and low quality tea (S6: 8.23mg/g) were relatively high, and that of Korean-made medium quality tea (S2 ; 4.87mg/g) was lower. The water temperature of 85$^{\circ}C$ and 95$^{\circ}C$ were high except in Korean-made medium and low quality powder green tea (S2 and S3). Japanese-made powder tea required 60 seconds of stirring time and Korean-made tea required 15 seconds, but 30 seconds seem to be the ideal stirring time for both of them. Chlorophyll a, b, pheophytin a, b, and pheophorbide were confirmed from the chlorophyll pattern. There were 1.5∼2 times more of chlorophyll a in Japanese-made one compared to that of Korean-made one; also 1.5∼2 times more of pheophytin a in Korean-made one than Japanese-made one. It might be concluded that Japanese-made powder green tea was higher in quality.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.615-623
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• 2000

The brine Korea cabbage (BKC) with various ingredients was stored at 5$^{\circ}C$ and 15$^{\circ}C$ for 13 days to examine the changes in pH, total acidity, ascorbic, and cholrophylls. Decrease in pH and increase in total acidity in the BKC stored at 15$^{\circ}C$ were greater than in the BKC stored at 5$^{\circ}C$, indicating these changes are closely related to the storage temperature. The effect of ingredints was various; garlic, red pepper powder, and fermented anchovy juice accelerated the decrease in pH and increase in total acidity; mustard powder and leaf mustard suppressed their changes and freen onion and ginger had no effect. At both temperatures, ascorbic acid was remained at high level in the BKC with leaf mustard, but it was maintained at lowest level in the BKC with ferented anchovy juice. Degradation od chlorophylls was slow in the BKC with leaf mustard, which maintained the high level os ascorbic acid during storage. Meanwhilr the degradation of chlorophylls or production of pheophytin and pheophorbide was cinsistent with the production of acid. These results suggset that degradation of chlorophylls in a BKC was positively correlated with ascorbic acid content and the acid produced during storage.

• Proceedings of the Korean Society of Sericultural Science Conference
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• 2004.04a
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• pp.44-44
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• 2004

• Journal of the Korean Society of Food Science and Nutrition
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• v.3 no.1
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• pp.13-16
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• 1974

The change in color of vegetables containing chlorophyll on cooking has been of concern to food scientists. This experiment was initiated to determine the effect of different heating methods and time on the chlorophyll of green pepper. Peppers were heated at 100 C for 5, 10, and 15 min by using boiling water, steam and hot air and for 1, 2 and 3 min in microwave oven. The results showed that chlorophyll content decreased with increasing heating time. Among the heat treatments employed steaming gave the greatest effect and boiling water was the next. Hot air and microwave treated samples changed only small amount of chlorophyll. Generally pheophytin formation was increased with decreasing chlorophyll content.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.6 no.1_2
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• pp.27-36
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• 1973

The effect of water activity on degradation of pigments in dried lavers, Porphyra tenera Kjellm. was examined when stored at room temperature for fifty days. Chlorophyll pigment was extracted with methanol-petroleum ether mixture solvent(2:1 v/v), partitioned in ether, and analysed spectrophotometrically at 662 nm as chlorophyll a. The degradation products of chlorophyll were isolated on sugar-starch column(85:15 w/w) with n-propanol-petroleum ether solution(1:200 v/v) as a developing solvent. The isolated green colored zones were analysed individually at the wavelengths of 650, 662, and 667 nm as allomerized product, chlorophyll a retained, and pheophytin formed respectively. Carotenoida were also extracted with the methanol mixture solvent, partitioned in ether, and finally redissolved in acetone after the evaporation of ether in a rotary vacuum evaporator. The total carotenoid content was measured as lutein at 450 nm. From the results, it is noted that the rate of chlorophyll degradation reached a minimum at 0.11 to 0.33 water activity while progressively increased at higher moisture levels resulting in rapid conversion of chlorophyll to pheophytin. At lower activity, autocatalysed oxidizing reaction like allomerization seemed prevailing the acid catalysed conversion reaction. The loss of carotenoid pigment was also greatly reduced at the range of 0.22 to 0.34 water activity with much faster oxidative degradation at both higher and extremely lower moisture levels. These two moisture levels indicated above at which the both pigments exhibited maximum stability are considerably higher than the BET monolayer moisture which appeared 7.91 percent on dry basis at Aw=0.10 calculated from the adsorption isothermal data of the sample at $20^{\circ}C$. The rate of pigment loss in heat treated samples at 60 and $100^{\circ}C$ for 2 hours prior to storage somewhat decreased, particularly at higher moisture levels although the final pigment retention was not much stabilized.

• Biotechnology and Bioprocess Engineering:BBE
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• v.6 no.2
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• pp.100-106
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• 2001

This investigation was performed to study the influence of benomyl on photosynthetic pigments and enzymes in soybean leaves. Chlorophyll and pheophytin levels were reduced by benomyl 45 days after greening. These results indicate that chlorophyll a and b, and pheophytin must be controlled by benomyl. SDS-PAGE analysis showed that 50 and 14.5 kD polypeptides represented as large and small subunits of rubisco. In the both of these subunits, the band intensity of the control was significantly higher than that after benomyl treatment, indicating that these two subunits are affected by benomyl. Benomyl strongly inhibited both the activity and content of rubisco as its concentration was gradually increased. However, it remains unclear whether this reduction of rubisco level was due to a reduced level of rubisco activase. Two major polypeptides of 46 and 42 kD were identified as rubisco activase subunits by SDS-PAGE. The intensity of these two bands was shown to be higher in the control than after benomyl treatment. These results indicate that the rubisco decrease resulting from increased benomyl concentrations was caused by rubisco activase. A significant decrease in both the activity and content of rubisco activase by benomyl was also observed. There results suggest that the decrease in rubisco level caused by benomyl is accompanied by a decrease in both the activity and content of rubisco activase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.4
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• pp.563-568
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• 1997

Changes of chlorophylls and carotenoids and antioxidative characteristics of crude chlorophylls and carotenoids(CCC) of mustard leaf kimchi(MLK) were investigated during the fermentation at 15$^{\circ}C$ for 25 days. At the beginning of fermentation chlorophylls were decreased rapidly, however, all chlorophylls and chlorophyllides were converted to pheophytins and pheophorbides at the final stage of fermentation. Total chlorophyll content remained constantly during the fermentation but 43.7% destruction of carotenoids was observed at 25 days of fermentation. Antioxidative activities of CCC from MLK against autoxidation of linoleic acid were significant(p<0.05) and much higher than those of $\alpha$-tocopherol. Fermentation period did not affect antioxidative activities of CCC of MLK. When the CCC of MLK was added to the autoxidation system of linoleic acid, degradation of total chlorophylls were observed to be slower than that of total carotenoids.

• Journal of Photoscience
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• v.8 no.2
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• pp.43-53
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• 2001

a, a parameter that describes how effectively photoinactivated PS II units protect their functional neighbours; car, carotenoids; ΔpH, transthylakoid pH difference; D1 protein, psbA gene product in the PS II reaction centre; f, functional fraction of PS II: F$\_$v//F$\_$m/, the ratio of variable to maximum chlorophyll a fluorescence; k$\_$d/, rate coefficient for degradation of D1 protein; k$\_$i/ and k$\_$r/, rate coefficient for photoinactivation and repair of PS II, respectively; NADP+, oxidized nicontinamide adenine dinucleotide phosphate; P680, the primary electron donor in the PSII reaction centre; Ph, pheophytin; PS, photosystem; Q$\_$A/, first quinone acceptor of an electron in PS II; R$\_$s/, the gross rate of D1 protein synthesis.