• Korean Journal of Food Science and Technology
• /
• v.38 no.2
• /
• pp.215-221
• /
• 2006

This study focuses on investigating the effect of porosity-controlled earthenware on fermentation of kanjang, Korean soy sauce. Porosity of fermentation vessel was controlled by changing the mixing ratio of raw soils at manufacturing earthenware. Earthenwares contented 0%, 40% and 60% of the mixture of red brown soil and powdered soil (1 : 1), respectively. The more contents of the mixed soil, the more porosity in earthenware. During fermentation of kanjang in porosity-controlled earthenwares at $30^{\circ}C$ for 4 months, physical, chemical, microbiological and sensory quality attributes were monitored. Compared to other containers, kanjang in the earthenware that had 0% mixed soil showed less water loss, salt content and pH. It also produced higher total acidity, protease activity, total nucleotide, and microbiological changes which included total aerobic bacteria, lactic acid bacteria and yeast. Total nitrogen and free amino acids in kanjang did not show the consistency with the mixed soil contents of fermentation containers, which may take more effect of other factors as water loss than the porosity of vessels. However, the percentage of glutamic acid in total free amino acids was a little higher in the earthenware that had 0% of mixed soil than other containers. These positive physicochemical, microbiological changes also resulted in higher sensory quality.

• Journal of the Korean Society of Food Culture
• /
• v.9 no.4
• /
• pp.411-417
• /
• 1994

The extraction condition and quality attributes components in Oolong tea were investigated. Extraction yield was high in $80{\sim}85^{\circ}C$ above 50% ethanol solution. Sucrose content most high among the free sugar ranged $37.2{\sim}55.0\;mg/100\;g$, while arabinose was the least. Organic acids in ethanolic extracts were furmaric, citric and malic acid. Free amino acids were 15 kinds and contents of proline, tyrosine and glutamic acid were comparatively high. Tannin content extracted from water and 25% ethanol solution were 38.6 and $38.5\;{\mu}g/100\;g$, it decreased as ethanol concentration increase. Caffeine content did not changed as extraction conditions. Ascorbic acid content was $6.5\;{\mu}g/g$ when extracted from 25% ethanol solution, it decreased as ethanol concentration increase. Bitter and astringent taste affected to overall preference of Oolong tea. Tea manufactured from 25% ethanol solution extracts recorded most high organoleptic score than any other extraction condition.

• Journal of Information Management
• /
• v.43 no.1
• /
• pp.109-134
• /
• 2012

This study, focusing on process of online Word-of-Mouth(oWOM) adoption in applications market which is a major issue of recent mobile industry, tried to empirically analyze how main characteristics of oWOM affect trust and process of oWOM adoption. To do this, based on understanding about applications market and precedent studies on online communication and Elaboration Likelihood Model(ELM), I developed the research model and proposed seven hypotheses. The subjects were smart phone users who ever used review in mobile applications market. The study method was questionnaire survey. As a result, trust in review was suggested as prerequisite for consumers to accept on-line review in mobile applications market. And it was empirically proved that for the customers to feel trust, these are necessary - positive assessment on argument quality, vividness of delivered explanation, and neutrality of message. The theoretical implications of this study are that based on studies on oWOM, factors affecting trust in review were explored in the environment of mobile applications market with less judgement clues for decision making compared to other on-line media and then, these factors were conceptualized. From the practical view, this study suggested implication on what attributes companies or developers can strategically utilize while investigating prerequisites of oWOM adoption.

• Journal of Korean Society of Environmental Engineers
• /
• v.34 no.3
• /
• pp.177-188
• /
• 2012

This study was mainly focused on the development of GIS based decision support system to easily make mitigation scenarios and to conveniently simulate water quality for TMDL. The study area was the 31km section of upper Sapgyo stream in Geum river basin, and QUAL2E model was adopted. GIS DB was built through the collection of the data which includes point/non-point source attributes and various thematic maps. The amounts of discharged loads of BOD, T-N and T-P from unit watershed were estimated respectively. Finally, the system, which can operate water quality simulation through simply modifying their values, was developed. The hypothetical three mitigation scenarios were applied, thereby the most efficient mitigation scenario could be chosen by comparison of the results based on GIS. Therefore, it is expected that the developed system can facilitate the decision makers to select the best alternative through the analysis of the available BMPs. Also, it can be used to develop new scenarios using different methods and algorithms. In the future, more study need to be made to enhance its applicability in the perspective of developing mitigation scenarios through the management of individual pollutant sources and extending study areas.

• Korean Journal of Ecology and Environment
• /
• v.42 no.2
• /
• pp.242-252
• /
• 2009

The purpose of this study was to develop a Multi-metric Water Quality Assessment (MWQA) model and apply it to dataset sampled from Paldang and Daechung reservoir in 2008. The various water dataset used to this study included 5 year data sets (2003${\sim}$2007) in Korean reservoirs which were obtained from the Ministry of Environment, Korea. In this study, suggested MWQA model has 4 metrics that were composed of 4 parameters such as chemical, physical, biological, and hydrological variables. And, each of the variables attributed total phosphorus (TP) concentration in water, secchi depth (SD) measure in water, chlorophyll-${\alpha}$(Chl-${\alpha}$) concentration in water and the ratio of inflow of water into lakes and efflux of water from lakes, input/output (I/O). First, we established the criteria for trophic boundaries. The boundary between oligotrophic and mesotrophic categories was defined by the lower third of the cumulative distribution of the values. The mesotrophic-eutrophic boundary was defined by the upper third of the distribution. Second, each metric was given by a point-oligo=1, meso=3, eu=5. And then, obtained total score from each metric was divided 5 grade-Excellent, Good, Fair, Poor, and Very poor. As the results of applying the proposed MWQA model, the Paldang reservoir obtained "Fair" or "Poor" grade and Daechung reservoir obtained "Excellent" or "Good" grade. The suggested MWQA model through these procedures will enable to manage efficiently the reservoir. And, more studies such as metric numbers and attributes should be done for the accurate application of the new model.

• Korean Journal of Food Science and Technology
• /
• v.45 no.1
• /
• pp.47-52
• /
• 2013

The feasibility of incorporating purple sweet potato concentrate (PSPC) as a value-added food ingredient in convenient food products, using a model system of jelly, was investigated. The pH and soluble solids content gradually increased with the increasing levels of PSPC added (p<0.05). The moisture content ranged from 82.03-83.82%. Lightness decreased, whereas redness and yellowness increased significantly with the higher amount of PSPC in the formulation (p<0.05). Turbidity and hardness also increased significantly (p<0.05). Total polyphenol content and DPPH radical scavenging activity increased significantly with the addition of PSPC (p<0.05). The consumer acceptance test indicated that the addition of PSPC had a favorable effect on consumer acceptances in all attributes. The jelly with 2% PSPC is recommended (with respect to the overall acceptance score) for taking advantage of the functional properties of PSPC without sacrificing consumer acceptability.

• Korean Journal of Food Science and Technology
• /
• v.45 no.1
• /
• pp.53-58
• /
• 2013

The effect of baking on the physicochemical and sensory properties was investigated using a model system of sponge cakes incorporated with pine leaf powder (PLP) as a value-added food ingredient. PLP was incorporated into cake batter at 5 levels (0, 2, 4, 6, and 8%, w/w) by adding an equivalent amount based on the weight of wheat flour. After appropriate mixing, sponge cakes were baked at $170^{\circ}C$ for 30 min in an oven. The baked cakes were cooled to room temperature for 1 h prior to all measurements. The pH, moisture content, specific volume, height, volume index, and symmetry index decreased significantly with the increase in PLP content (p<0.05). On the contrary, specific gravity of the batter and baking loss increased (p<0.05). The lightness of the cakes decreased, whereas redness increased significantly with the higher amount of PLP in the formulation (p<0.05). Hardness also increased significantly (p<0.05). Both total polyphenol content and DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activity increased significantly by the addition of PLP (p<0.05). The consumer acceptance test indicated that the addition of PLP up to 4% did not cause a significant unfavorable effect on the consumer acceptances in all attributes. The sponge cakes with 2-4% PLP would be recommended with respect to the overall acceptance score while taking advantage of the functional properties of PLP without sacrificing the consumer acceptability.

• Korean Journal of Food Science and Technology
• /
• v.28 no.1
• /
• pp.44-52
• /
• 1996

Sensory properties of cooked rice were affected by the varieties and growing environments of the rice. Moistness, cohesiveness, and adhesiveness of cooked rice were highly and positively correlated each other, whereas firmness was negatively correlated with these attributes. Sixty rice samples which differed in varieties and/or growing environments were divided into four groups based on their textural properties through principal component analysis and cluster analysis. Quality type I showed the highest values for moistness, cohesiveness, and adhesiveness, and the lowest values for firmness of cooked rice. On the other hand, quality type IV showed just the opposite values. There was no significant difference among rice starches in amylose content (P<0.05). A17 (type III) and A09 (type IV) had higher blue values for starch and amylopectin than the other samples (type I and II). On the amylogram, these samples showed lower values for breakdown and higher values for setback than the other samples. Average degree of polymerization, average chain length, and average number of chains for amylose and amylopectin were 597-878 and 2660-3140, 140-230 and 17-19, and 3.1-4.9 and 140-170, respectively.

• Food Science and Preservation
• /
• v.6 no.4
• /
• pp.351-356
• /
• 1999

To develop and extend the shelf-life of vitamin C enriched fresh-cut apples using CA stored Fuji apples, dipping in 10% L-ascorbic acid and packaging with 0.03 mm LDPE, 0.04 mm PP and 0.08 mm Nylon/PE film(N$_2$displacement) were carried out. The changes of gas concentrations in the packaging and quality attributes of fresh-cut apples were examined during storage at 10$^{\circ}C$. The concentrations of O$_2$was maintained lower in Nylon/PE film than the other film, the level of O$_2$was in the range of 1∼3%. The increase of C$_2$H$_4$ concentrations in Nylon/PE film bag was more suppressed than the others. The vitamin C content of fresh-cut apples was enriched by dipping in L-ascorbic acid solution up to 241 mg$.$100 g-1 f.w., and the loss or that content was retarded differently by the package conditions of lower O$_2$level during storage. Browning in fresh-cut apples was shown after 6 days of storage in LDPE and PP film. but it was not shown by 14 days of storage in Nylon/PE film. Spoilage and off odor in fresh-cut apples were not detected up to 14 days of storage in Nylon/PE film. The results indicated that the vitamin C enriched fresh-cut apples can be processed from the long-term CA stored apples, and maintaining high quality of the products ill be possible in cases of the application of sealing packaging after O$_2$removal with film having low O$_2$permeability.

• Food Science and Preservation
• /
• v.16 no.4
• /
• pp.463-471
• /
• 2009

We evaluated the physicochemical properties and sensory characteristics of, bioactive compounds in grape juice prepared from different grape varieties grown in Korea, such as Campbell Early, Steuben, and Muscat Bailey A (MBA), with respect to heating time (30, 45, or 60 min) and temperature ($60^{\circ}C$, $70^{\circ}C$, $80^{\circ}C$, or $90^{\circ}C$). We found that long heating time and high temperature, especially treatment at $90^{\circ}C$ for 60 min, significantly affected the physicochemical properties and bioactive compound levels of grape juice. Among the grape juice varieties, Campbell Early juice had the highest level of bioactive compounds. Sensory evaluation scores showed that heating of musts at $80^{\circ}C$ for 30 min was associated with the most preferred sensory attributes for Campbell Early grape juice, whereas the most preferred juices from Steuben and MBA grapes were from musts heated at $70^{\circ}C$ for 60 min and at $70^{\circ}C$ for 30 min, respectively. The bioactive compounds of juice from the three grape varieties were optimal using the above-mentioned processing times and temperatures.