• Journal of Korean Society on Water Environment
• /
• v.36 no.4
• /
• pp.322-331
• /
• 2020

By introducing chemically enhanced primary treatment (CEPT) in the first stage of sewage treatment, organic matter in sewage can be effectively recovered. Because CEPT sludge contains a high biodegradable organic matter in volatile solids (VS), it is feasible to convert the collected CEPT sludge into energy through anaerobic digestion. This study examined the properties and biochemical methane potential (BMP) of the CEPT sludge obtained from a sewage treatment plant located in an ocean area. The CEPT sludge contains a VS content of 37,597 mg/L, which is higher than that of excessive sludge (ES), i.e., 33,352 mg-VS/L. In the methane generation reaction, the lag period was as short as 1 to 2 days. The BMP for the CEPT sludge was 0.57 ㎥-CH₄/kg-VS_removed which is better than that of ES, i.e., 0.36 ㎥-CH₄/kg-VS_removed. Unfortunately, the CEPT sludge showed a high salinity as 0.56~0.75% probably due to the saline sewage. Due to the salinity, repeated BMP testing in a sequencing batch reactor showed significantly low methane production rates and BMPs. Also, the ES showed a strongly reduced BMP when the salinity was adjusted from 0.20 to 0.70% by NaCl. The ES mixture with higher CEPT content showed a better BMP, which is suitable for co-digestion. Besides, anaerobic digestion for 100% CEPT sludge can be a considerable option instead of co-digestion.

• Korean Journal of Environmental Agriculture
• /
• v.38 no.2
• /
• pp.69-75
• /
• 2019

BACKGROUND: Measurement of electrical conductivity of saturated soil paste ($EC_e$) for assessment of soil salinity is time-consuming, and thus conversion of EC of 1:5 soil-water extract ($EC_{1:5}$) to $EC_e$ using a dilution factor may be of help to monitor salinity of huge number of soil samples. This study was conducted to evaluate the dilution factor for reclaimed tideland (RTL) soils of South Korea. METHODS AND RESULTS: Soil samples (n=40) were collected from four RTLs, and analyzed for $EC_{1:5}$, $EC_e$, and cation compositions of 1:5 soil-water extract. The dilution factor (8.70) was estimated by regression analysis between $EC_{1:5}$ and $EC_e$, and the obtained dilution factor was validated by applying to an independent data set (n=96) of $EC_{1:5}$ and $EC_e$. The $EC_e$ measured and predicted was strongly correlated ($r^2=0.74$, P<0.001), but $EC_e$ was overestimated by 16% particularly for the soils with high clay content and low sodium adsorption ratio (SAR). CONCLUSION: This study suggests that using the dilution factor to convert $EC_{1:5}$ to $EC_e$ is feasible method to monitor changes in the soil salinity of the study RTL. However, overestimation of $EC_e$ should be cautioned for the soils with high clay content and low SAR.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.4
• /
• pp.380-386
• /
• 1999

Fermented sausages inoculated with starter cultures which were combined Lactobacillus curvatus and Staphylococcus carnosus(LCSC), Lactobacillus plantarum and Staphylococcus carnosus(LPSC) were manufac-tured. changes in chemical composition salinity weight loss fatty acids inosine monophosphate(IMP) and hypoxanthine (Hx) and fee amino acids during ripening of fermented sausages were investigated. Due to drying the water content was decreased while the protein and fat contents salinity and weight low were increased during ripening. No significant differences between LCSC and LPSC were found for chemical composition salinity and weight loss. During ripening unsaturated fatty acid contents was dec-reased while saturated fatty acid contents was increased. At the end of the ripening the levels of mon-oenes were slightly higher in the LPSC than in the LCSC. In both treatments IMP contents were dec-reased but no changes were observed in Hx contents during ripening. Due to ripening the increase in total and individual free amino acids were observed and contents of glutamic acid alanine leucine and lysine were greatly increased.

• Korean Journal of Community Nutrition
• /
• v.18 no.5
• /
• pp.478-490
• /
• 2013

Dietary habit of excess sodium consumption is formed mainly by excessive salt intake from the younger age and this may lead to hypertension, stroke, and stomach cancer. This study was performed to estimate the salt content in kindergarten meals and provide basic data on meal providers' dietary attitude to sodium intake for nutrition education. We collected data on161 food items from 16 institutions in Gyeonggi-do and salt content was calculated from salinity and weight of individual food items. The average salt content from lunch meals was 2.2 g, which was about daily adequate intake of sodium for children aged 3 to 5 years old. Greatest contributor to the salt content in a meal was soup and stew (47.8%). The most salty dishes were sauces and kimchi followed by stir-fried food, deep-fried food, braised food, and grilled food. The salt content was higher in soup and stew despite of low salinity, due to the large quantity per serving. The salt contents of soups and kimchi were 40.6% and 14.3%, respectively of the total salt content in dish groups. Staff members and caregivers at home who prepared food for the child showed preference for one-dish rice meal, dried fish and salted mackerel, and broth when eating soup, stew, and noodles. Caregivers showed higher sodium index score and had higher preference for processed food such as Ramen, canned food, and ham compared with staff members (p < 0.05). These results suggested that monitoring salt content of kindergarten meals and nutrition education for those prepare meals for children are needed to lower sodium intake in childhood.

• Horticultural Science & Technology
• /
• v.34 no.4
• /
• pp.564-577
• /
• 2016

Salinity stress limits plant cultivation in many areas worldwide; however, persimmon (Diospyros spp.) has high tolerance to salt. Five accessions of Diospyros [three of Diospyros lotus (accession numbers 824, 846, and 847); one of Diospyros kaki var. sylvestris (869); and one of Diospyros virginiana (844)] were chosen for analysis of salinity stress. We compared the effects of salt stress on plant growth, relative water content (RWC), malondialdehyde (MDA), electrolyte leakage (EL), hydrogen peroxide content ($H_2O_2$), and antioxidative enzyme activities (superoxide dismutase, SOD; catalase, CAT; peroxidase, POD; and ascorbate peroxidase, APX) in leaves of healthy potted seedlings from each of the five accessions after salt treatment for 25 days. Salt stress affected the growth of plants in all five accessions, with all three D. lotus accessions showing the most severe effect. Salt stress increased membrane lipid peroxidation in all accessions, but a stronger increase was observed in the three D. lotus accessions. Moreover, accumulation of $H_2O_2$ was faster in salt-sensitive D. lotus compared to salt-tolerant D. virginiana 844. The activities of all antioxidant enzymes increased in D. virginiana 844 and in D. kaki var. sylvestris 869; the activities of SOD, CAT, and APX were at similar levels in D. virginiana 844 and D. kaki var. sylvestris 869, but POD activity was stimulated to a greater extent in D. virginiana 844. The activities of all antioxidant enzymes (except POD) decreased in D. lotus 824 and increased (except for SOD) in D.lotus 846. The activities of SOD and APX decreased in D. lotus 847, whereas POD and CAT activities both increased. Relative water content decreased significantly in D. lotus. No significant changes in lipid peroxidation or relevant antioxidant parameters were detected in any of the accessions in controls treated with 0.0% NaCl. D. virginiana 844 had higher antioxidant capacity in response to salinity compared to other persimmon rootstocks. These results indicate that changes of these key physiological variables are related to salinity resistance in different accessions of persimmon.

• The Korean Journal of Community Living Science
• /
• v.23 no.1
• /
• pp.79-88
• /
• 2012

To evaluate the possibility of low-salinity of traditional fermented food, we investigated quality characteristic of low-salted Yacon Jangachi using soybean sauce with sugar or vinegar for 50 days. Sugar content, titration acidity, and salinity of all Yacon Jangachi was increased as storage time increased. All of the Yacon Jangachi had less than 3.0% salinity. Especially, the salinity of the Yacon Jangachi with sugar and vinegar was the lowest during storage time. The L value was decreased as storage time increased but the results of the a and b values were reversed. Cutting force was not significant among samples and storage periods. In the results of sensory evaluation, preference of all samples were increased as storage time increased. The preference of color was not significant among samples from 30 days but the taste was reversed. The preference of flavor was significant between samples in 40 days, texture was not significant during storage time. Overall preference was not significant after 30 days, which suggested that Yacon Jangachi using soybean sauce retains overall preference in steady level from 30 days. Yacon Jangachi using soybean sauce showed the highest preference when produced with sugar and vinegar.

• Food Science of Animal Resources
• /
• v.35 no.6
• /
• pp.748-756
• /
• 2015

The effects of sea tangle, sea mustard, hijiki, and glasswort were investigated based on the proximate composition, salinity, cooking loss, emulsion stability, pH, color, texture profile analysis, apparent viscosity, and sensory characteristics of reduced-salt (NaCl) meat batter and frankfurters. The moisture content, salinity, lightness of the meat batter and frankfurter, hardness, gumminess, and chewiness of the reduced-salt frankfurters with sea weeds were lower than the control without seaweed (p<0.05). The protein content, springiness, and cohesiveness of the reduced-salt frankfurters were not significantly different among the treatments (p>0.05). The moisture content, salinity, cooking loss, lightness, redness, hardness, gumminess, and chewiness of treatments with sea tangle and with sea mustard were lower than the control (p<0.05). Among the sensory traits, color was highest in the control (p<0.05). The flavor was also highest in the control. The treatments with sea tangle and with sea mustard samples had high tenderness, juiciness, and overall acceptability scores similar to the control (p<0.05). The results of this study show that the combination of low-salt and seaweed in the formulation successfully improved reduced-salt frankfurters, improving sensory characteristics to levels similar to the regular salt control (1.5%).

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.48 no.6
• /
• pp.839-848
• /
• 2015

This study examined the optimal salting drying method and processing conditions (salt concentration, curing time, dry temperature, and drying time) for preparing salted semi-dried common gray mullet (SSD-CGM) Mugil cephalus based on the moisture content, salinity, and overall acceptance using response surface methodology (RSM). The moisture content, salinity, and overall acceptance of SSD-CGM prepared with different salting methods revealed that dry salting was the optimal salting method for preparing high-quality SSD-CGM. The optimal drying method for preparing high-quality SSD-CGM based on the drying velocity and sensory color was hot air-blast drying. The results of the RSM program indicated that the optimal independent variables ($X_1$, salt concentration; $X_2$, curing time; $X_3$, dry temperature; $X_4$, drying time) based on the dependent variables ($Y_1$, moisture content; $Y_2$, salinity; $Y_3$, overall acceptance) for high-quality SSD-CGM were 5.6% for $X_1$, 2.7 h for $X_2$, $47.0^{\circ}C$ for $X_3$, and 8.5 h for $X_4$ for uncoded values. The predicted values of $Y_1$, $Y_2$, and $Y_3$ for SSD-CGM prepared under optimal conditions were 54.4%, 4.2%, and 6.3, respectively, while the experimental values were $55.2{\pm}1.0%$, $4.1{\pm}0.3%$ and $6.7{\pm}0.8$. The actual and predicted values did not differ.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.3
• /
• pp.553-564
• /
• 2013

The core ingredient of traditional Korean style soy sauce is soy bean without any wheat or rice incorporated. National brands as well as regional micro-brewed companies constitute the soy sauce market in Korea. The present study investigated the physico-chemical and sensory properties of soy sauces produced by small-scale or mass-production. Additionally, the key physico-chemical parameters sufficiently representing the critical sensory characteristics have been identified. Ten types of soy sauce brewed by the Korean traditional method were selected for the study. Among these samples, seven types were brewed in small-scales in the Gyeonggi-do region whereas the other 3 types were mass-production products of major national brands. The total solid, reducing sugar, salinity, sugar content, amino nitrogen, CIELAB, acidity, and pH of soy sauce samples were measured for the physico-chemical analysis. A generic descriptive analysis was conducted to analyze the sensory characteristics of the samples using six trained panelists. The descriptive panel developed 21 sensory attributes. The data were statistically analyzed using ANOVA, PCA and PLSR. Overall, the micro-brewed products showed significantly higher value of salinity and acidity but lower content of reducing sugar than the mass-production products. The micro-brewed soy sauces elicited stronger fermented flavor, sourness, and bitterness whereas the national brand products elicited stronger alcoholic odor, sweetness and umami taste. Sugar content, acidity, and amino nitrogen showed strong relationships with fish sauce flavor, umami taste, and rich flavor. Salinity was closely related to the overall flavor intensity.

• Food Science and Preservation
• /
• v.21 no.4
• /
• pp.500-505
• /
• 2014

This study investigated the effects of the steeping condition and salinity stress on the quality properties of germinated black soybean. The absorbed water content increased drastically in six hours with the increase in the steeping time and the temperature. The pH decreased as the steeping temperature increased. A gradual increase in the dissolution of the anthocyanin was observed with the steeping time. The adequate steeping conditions were found to have been six hours at $25^{\circ}C$, which showed the needed absorbed water content within a short time. The germination percentage of the black soybeans decreased with the increase in the NaCl concentration. The pinitol and total phenolics contents showed the highest values under the concentrations of 0.7% and 0.3-0.5% NaCl, respectively. The flavonoid content was highest at the 0.1% NaCl concentration. Consequently, the salinity stress during the germination of the black soybeans enhanced the pinitol content and lowered the blood sugar, which gives it an advantage as a functional food material.