• Journal of Wetlands Research
• /
• v.7 no.2
• /
• pp.37-52
• /
• 2005

Vertical distribution of bacterial population and activities were compared between the muddy and sandy sediment of the tidal flat located in southern area of Ganghwa Island. The average of bacterial number and activities in mud flat was slightly higher than that in sand flat. Bacterial number was markedly increased at the sandflat during the investigation period, which seemed to be the result of increase of mud content. The number and activities of microorganisms in mudflat was comparable to that of the mangrove sediments. There was no differences in bacterial number with the depth, but the aminopeptidase activity and bacterial productivity were decreased markedly within 3~5cm depth of sediment due to the availability of carbon sources and molecular oxygen in pore water. The number and activities of microorganisms in mudflat did not correlated with the distribution of benthic microalgae; however, those in sand flat were closely correlated with the distribution of benthic microalgae. The distribution of marsh plant in the mudflat area might be the reason of the difference.

• Korean Journal of Plant Resources
• /
• v.17 no.3
• /
• pp.314-322
• /
• 2004

This research has been undertaken to increase availiability of native Camellia japonica leaf and flower in Korea as a edible-medicinal resource. Chemical compositions, antioxidant and antimicrobial activities in different parts of camellia were investigated. Crude protein contained the highest in young leaves(14.22%) but less than 10% in different parts. The contents of crude fat and crude ash were 60.48% in seeds and 5.16% in mature leaves, respectively. Methanol extract of young leaf, flower, and flower bud in camellia showed strong antioxidant activity compared with different parts. Also, antioxidant activity of these was higher than that of BHT, but weaker than that of VtC. Antioxidant activity of various parts in camellia were in order of young leaf ＆gt; flower bud ＆gt; flower ＆gt; mature leaf ＆gt; stem ＆gt; bark. Extracts of mature leaf and bark had a remarkable antibacterial activity(0 CFU/$m\ell$) on Bacillus subtilis. The young leaf extract displayed effective growth inhibition against B. subtilis, Candida albicans, and Trichosporon beigelii.

• Culinary science and hospitality research
• /
• v.17 no.1
• /
• pp.248-258
• /
• 2011

To analyze die quality characteristics of loaf bread added with waxy black rice flour by its storage period, this study stored loaf bread made of wheat flour added with 10% 20% 30% and 40% of waxy black rice flour for 4 days while measuring water activity, pH, chromaticity and texture. The results of die study are as follows. Based on die results of measurements of water activity of loaf bread added with waxy black rice flour by storage period, die control group and die groups added with 10% and 20% of waxy black rice flour showed significantly low water activity from the $3_{rd}$ day of storage and die groups added with 30% and 40% of waxy black rice flour from the $2_{nd}$ day of storage. As for pH changes over the storage period, only die group added with 40% of waxy black rice flour showed significant pH decreases from die $3_{rd}$ day of storage while the control group and the groups added with 10% and 30% of waxy black rice flour showed significant pH decreases from die $2_{nd}$day of storage. As for the pH of each group of loaf bread by storage days, die loaf bread added with 40% of waxy black rice flour showed significantly higher pH compared to the control group. Brightness decreased significantly from the 2nd day of storage and die yellowness from the $3_{rd}$ day of storage. As for chromaticity changes by storage days, as die amount of added waxy black rice flour increased, L values and b values decreased while redness values significantly increased. Over die storage period, hardness, gumminess and chewiness increased and die waxy black rice flour added groups showed lower increase rates compared to die control group. Especially, die groups added with 30% and 40% of waxy black rice flour showed low hardness changes. Springiness level was decreased as die addition rate of waxy black rice flour was increased, and the group added with 40% of waxy balck rice flour showed die lowest springiness level. It also showed lower cohesiveness up to the 3rd day of storage compared to die day of manufacturing. Therefore, it could be seen that die loaf bread made from wheat flour added with 30% of waxy black rice flour showed better quality feature until die $3_{rd}$ day of storage than die other experimental groups.

• Food Science and Preservation
• /
• v.22 no.1
• /
• pp.84-90
• /
• 2015

The physicochemical properties and protease activities of spray-dried pineapple juice powders were investigated. The pH, soluble solids, and protease activity of the pineapple juice were pH 5.43, $12.8^{\circ}Brix$, and 4.82 unit/mL, respectively. The optimum pH and temperature of the protease activity from pineapple juice were pH 7.0 and $50^{\circ}C$, respectively. The microencapsulation of pineapple juice was achieved using maltodextrin and alginic acid through spray-drying. The L value and moisture content of the spray-dried powder were higher than those of the freeze-dried powder. The particle size of the freeze-dried powder ($501.57{\mu}m$) was higher than that of the spray-dried powder ($42.58-53.32{\mu}m$). The water absorption and water solubility of the powders were 0.41-0.87, and 90.45-99.76%, respectively. When compared, the protease activities were found to be in the following order : FD (1,297.47 unit/g) > SD-MA-1 (692.08 unit/g) > SD-MA-2 (664.66 unit/g) > SD-MA-3 (642.65 unit/g) > SD-M (633.51 unit/g). In the in vitro dissolution study measurements were conducted for 4 hr in pH 1.2 simulated gastric fluid and pH 6.8 simulated intestinal fluid, using a dissolution tester at $37^{\circ}C$ in 50 rpm. The protease survival of the 3.74-15.69% microencapsulated pineapple juice powders improved with an increase in the treatment concentration of alginic acid.

• Applied Biological Chemistry
• /
• v.26 no.4
• /
• pp.239-247
• /
• 1983

The effects of some soil conditions on the degradation rate and decomposing pattern of parathion were investigated and the obtained results are summarized as follows: Parathion degraded more rapidly in flooded soils than in non-flooded, in wet soils than in dry soils under non-flooded soils. The degradation rates in paddy and upland soils increased at high temperature than low temperature, higher pesticide concentration than low concentration and higher soil pH level. Parathion in paddy and upland soils was more persistent under soil sterilization than under non-sterilization and degraded rapidly in glucose application. Parathion was more persistent in upland soils than paddy soils under several factors described above. The metabolites identified from the paddy and upland soils by TLC include para-oxon (Rf 0.5), aminoparathion(Rf 0.27), p-nitrophenol(Rf 0.2), p-aminophenol(Rf 0.15). Soil enzyme, acid phosphatase activities decreased more at flooded soils than non-flooded, higher pesticide concentration than low concentration and higher soil pH level and the activity in glucose application was increased. Soil enzymes, urease and dehydrogenase activity decreased more at higher pesticide concentration than low concentration. Comparing with soil enzyme activity in paddy and upland soil, the former was higher than the latter.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.591-597
• /
• 2015

In this study, extracts of chlorella using different extraction methods were compared for antioxidant activities and spray-dried chlorella powders were investigated for their physicochemical characteristics. The DPPH radical scavenging activity and superoxide radical scavenging activity of 50% ethanol extract were 29.19%, and 48.91%, respectively. The oxygen radical absorbance capacity (ORAC) of the 50% ethanol extract ($150.44{\mu}M/g$) was higher than those of other extracts. The total chlorophyll content of the 50% ethanol extract (542.89 mg/100 g) was higher than those of other extracts. The microencapsulation of the 50% ethanol extract was manufactured by spray-drying with 10 % maltodextrin (SD-C10), 20% maltodextrin (SD-C20), and 30% maltodextrin (SD-C30). The particle size of the freeze-dried powder ($454.47{\mu}m$) was higher than those of the spray-dried powders ($24.15{\sim}32.49{\mu}m$). Scanning electron microscope images showed that the spray-dried chlorella powders using SD-C10, SD-C20, and SD-C30 had an uniform particle distribution. The water absorption index and water solubility index (WSI) of powders were 0.31~0.45, and 96.96~98.28%, respectively. The spray-dried powders showed the stability in total chlorophyll content for 40 days storage. Based on these results, spray-dried chlorella powders could be used in various types of food processes.

• Food Science and Preservation
• /
• v.22 no.4
• /
• pp.585-590
• /
• 2015

As consumers are aware of their health and are more conscious of environmental conditions, there is an increasing demand for organic agri-foods. The present study aims to investigate the physicochemical quality characteristics and antioxidant activity of organic green peppers. The weight, length, moisture content, color (Hunter L, a, b) and hardness were measured for the quality characteristics. In addition, the DPPH, ABTS radical scavenging activities and total phenolic contents were analyzed for the comparison of antioxidant activities between organically and conventionally grown green peppers. The weight and length of the organically grown green peppers were lower than those of the conventionally grown ones. The moisture content of the organically and conventionally grown green peppers was similar. The L and b values of the organically grown green peppers were higher than those of the conventionally grown ones. The DPPH radical scavenging activity of the organically grown green peppers (62.86%) was higher than that of the conventionally grown ones (51.06%). The total phenolic content of the organically grown green peppers was higher than that of the conventionally grown ones, however, there was no significant differences between organically and conventionally grown green peppers (p<0.05). Further studies would be recommended for the evaluation of other characteristics such as flavor, taste, and bioactivity compounds between organically and conventionally grown green peppers.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.46 no.1
• /
• pp.140-145
• /
• 2017

Pinus koraiensis cone (PKC) extract was prepared by mixing PKC with sugar at a weight ratio of 1:1 and then removing PKC after incubating the mixture at room temperature for 100 days. The resulting PKC extract was examined for its physicochemical properties and antioxidant activities using Prunus mume fruit extract, which is similar to PKC extract in terms of preparation procedure and product usage, as a control. PKC extract consisted mainly of moisture (21.76%) and sugar (70.03%), leading to high viscosity. PKC extract was apparently yellowish, and therefore its browning index and color intensity were appreciably lower than the control (P=0.0000), indicating that Maillard reaction was not facilitated during fermentation. Compared with the control, PKC extract was not appreciably different in terms of total flavonoid content, whereas its organic acid content and total reducing capacity were significantly lower. Nevertheless, its metal-chelating activity and DPPH radical scavenging activity were comparable to those of the control. In addition, SOD-like activity of PKC extract was 2-fold higher than that of 6.6 mM quercetin, which had a higher total flavonoid content than PKC extract. This indicates that PKC extract contains certain flavonoids with higher antioxidant activities than quercetin. The results show that PKC extract provides antioxidant activity as well as characteristically different sensory properties due to its higher sugar and lower organic acid contents compared with Prunus mume fruit extract.

• Journal of Mushroom
• /
• v.18 no.1
• /
• pp.63-71
• /
• 2020

The present study aimed to investigate the biological activities and nutritional contents of extracts from three types of edible mushrooms (Pleurotus ostreatus, P. eryngii, and Hericium erinaceus) following different roasting treatments. Roasting by a household multi-oven (HR60) decreased the total polyphenol contents, as well as DPPH radical scavenging and nitrite scavenging activities compared with the fresh samples, and no significant difference was observed between the different roasting times. As a result of rotary drum roasting (CR) treatment, we could observe a decrease in the DPPH radical scavenging activity in all roasted mushroom samples compared with the fresh samples, whereas nitrite scavenging activity increased in roasted P. eryngii and H. erinaceus. Additionally, total polyphenol contents increased significantly in roasted H. erinaceus. In each roasted sample dried by HR60 and CR, the amount of palatable-taste amino acids (e.g., glutamic acid) and sweet-taste amino acids, including glycine, serine, alanine, and threonine, increased in P. ostreatus, whereas the amount of bitter amino acids, including leucine, isoleucine, histidine, valine, and methionine, decreased compared with the fresh samples. In P. eryngii and H. erinaceus samples, we also observed an increase in the amount of palatable and sweet-taste amino acids upon the roasting treatments; however, the amount of bitter amino acids increased simultaneously following the roasting treatments. These results suggest that CR treatment is more effective in increasing the biological activities and nutritional contents, such as palatable and sweet-taste amino acids, compared with HR60 treatment.

• Clean Technology
• /
• v.16 no.2
• /
• pp.132-139
• /
• 2010

The Cu-Mn mixed oxide catalysts with different molar ratios of Cu/(Cu+Mn) prepared by co-precipitation method have been investigated in CO oxidation at $30^{\circ}C$. The catalysts used in this study were characterized by X-ray Diffraction (XRD), $N_2$ sorption, X-ray photoelectron spectroscopy (XPS), and $H_2$-temperature programmed reduction $(H_2-TPR)$ to correlate with catalytic activities in CO oxidation. The $N_2$ adsorption-desorption isotherms of Cu-Mn mixed oxide catalysts showed a type 4 having pore range of 7-20 nm and BET surface area was increased from 17 to $205\;m^2{\cdot}g^{-1}$ with increasing of Mn content. The XPS analysis showed the surface oxidation state of Cu and Mn represented $Cu^{2+}$and the mixture of $Mn^{3+}$ and $Mn^{4+}$, respectively. Among the catalysts studied here, Cu/(Cu+Mn) = 0.5 catalyst showed the highest activity at $30^{\circ}C$ in CO oxidation and the catalytic activity showed a typical volcano-shape curve with respect to Cu/(Cu+Mn) molar ratios. The water vapor showed a prohibiting effect on the efficiency of the catalyst which is due to the competitive adsorption of carbon monoxide on the active sites of catalyst surface and finally the formation of hydroxyl group with active metals.