• Journal of the Korea Organic Resources Recycling Association
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• v.8 no.3
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• pp.118-123
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• 2000

Food waste results in various problems such as decay, odors and leachate in collection, transportation and landfill due to the high volatile solids and moisture content. Acidogenic fermentation of food waste is influenced by the environmental conditions such as pH, retention time, etc. Each component of food waste is degraded under the different environmental conditions. Starch, cellulose and protein have their own optimum pHs and retention times for degradation. The degradation of starch increases at low pH, cellulose with increasing retention time, and protein with increasing retention time as well as approaching neutral pH. These mean that the degradation of food waste can be enhanced by adjusting the environmental conditions of acidogenic fermentation. The efficiency of acidification increased from 71.2 to 81.1% by controlling dilution(D) rate from 3.0 to $1.0d^{-1}$ depending on the state of the fermentation. The main component of the acidified product was shifted from butyric to acetic acid, indicating that the increase of acidification was mainly caused by the enhanced degradation of vegetables and meats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.16 no.4
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• pp.268-277
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• 1987

The changes of the aerobic viable bacterial counts, the content of chemical components and the sensory evaluation in Kimchis which were prepared with Various ingredients (red pepper, green onion, garlic and ginger) and fermentation at $20^{\circ}C$ were investigated. Aerobic viable bacterial counts were suddenly decreased with fermentation, but it was decreased slowly from the second day. Salinity of Kimchis was $1.8%{\sim}2.0%$ and titratable acidify were lower in sample 2 (deleted red pepper) and 3 (deleted green onion) on the first day but sample 4 (deleted garlic) after the fifth day. Total sugar content was decreased from $1.8{\sim}2.7g/100g$ to $0.8{\sim}1.1g/100g$ during fermentation periods. Carbon dioxide content maintained relatively higher in sample 2 and 5 (deleted ginger) with fermentation. Volatile organic acid content showed no difference in all Kimchis with fermentation. During the whole fermentation period, appearance was the worst in sample 2. Texture, off-flavor and overall-eating quality were the worst in sample 4. Carbonated flavor and overall eating quality were the best in sample 5.

• Korean Chemical Engineering Research
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• v.50 no.6
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• pp.952-959
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• 2012

The photocatalytic reactor was designed to have improved efficiency by enhancing a light intensity of photocatalytic reactor using a reflector coated on the surface at the outer radius of annular shaped photocatalytic reactor. The improved photocatalytic reactor performed to treat waste air containing malodor and VOC with the enhanced light intensity, of which the effect on their removal efficiency was investigated. The intensities of illumination of the improved photocatalytic reactor filled with porous silica-based media and nonporous glass bead media carrying photocatalyst were observed to increase by 28.5% and 30.1%, respectively, compared to those of photocatalytic reactor without any reflector. Using the improved photocatalytic reactor filled with porous silica-based media and nonporous glass bead media carrying photocatalyst, the removal efficiencies were enhanced by 2~3% and insignificantly, respectively. The removal efficiencies of the optimized photocatalytic reactor with reflectors, filled with porous silica-based media carrying photocatalyst, were observed to increase by 26% and 60%, compared to those of photocatalytic reactor (i.e., 19% and 53%), without any reflector, filled with nonporous glass bead media carrying photocatalyst, for hydrogen sulfide and toluene, respectively. The roughness of used reflector surface was measured to be ca. four times as big as that of a commercial mirror. However, their removal efficiencies are expected to be enhanced by increasing an light intensity resulting from lowering the roughness of used reflector coated on the improved photocatalytic reactor in the future.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1682-1689
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• 2013

The objective of the present study is to elucidate the physicochemical and microbial properties of Korean traditional rice wine, Makgeolli, supplemented with mulberry during the fermentation process. Four hundred grams of mulberries (20% of the total amount of rice) were ground and incorporated into the rice solution (3.5 L of distilled water, 2.0 kg of rice, 28.0 g of yeast, and 80.0 g of nuruk). The rice solution was then placed in a water bath set at $28^{\circ}C$ and left to ferment for 7 days. The alcohol contents between the control and mulberry Makgeolli were not significantly different. The pH values of the control and mulberry Makgeolli decreased and the total acidity values were elevated after a 7-day fermentation. In the microbial analysis, the total viable cell count, lactic acid bacteria count and yeast count increased considerably through the 7-day fermentation process. For all the samples, the glucose and succinic acid contents were highest among all free sugars and organic acids, respectively. Forty-eight different volatile compounds were found in all the samples after the 7-day fermentation process.

• Korean journal of food and cookery science
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• v.2 no.1
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• pp.38-44
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• 1986

Effects of the kind and concentration of salt on oxidation of lipids and on formation of flavor components have been studied with four varieties of fermented anchovies prepared with 20％ sun-dried salt(sample B) , 12% refined salt (sample C), 16.5％ refined salt (sample D) and 16. 5% refined salt Plus 25％ brine (sample E). The sample B showed higher peroxide and TBA value and also higher content of TMA thar. those prepared with refined salt. The amounts of amino-N and VBN in sample B appeared larger than in sample D but was in a similar level with those in sample C. On the other hands, much smaller amounts of lactic and succinic acid were observed in sample B compared with in sample C and D. Sample C revealed the highest level of lactic acid among the samples tested. The changes in the amounts of each free amino acid displayed similar tendencies in all samples, except decreasing tendency of tyrosine in sample B and increasing tendency of aspartic acid in sample C. Also observed was lower IMP and inosine level in sample B than in C and D, but hypox-anthine level was higher in B. In general, sample I indicated remarkably lower values of experimental data in all cases mentioned above, but the highest TBA balue.

• Korean Journal of Food Science and Technology
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• v.30 no.3
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• pp.608-614
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• 1998

In order to establish the scientific foundations for the production of Korean traditional kanjang (soy sauce) in a semi-pilot scale, meju preparation and kanjang mashing methods were investigated. Two types of meju, one that was prepared by conventional method (CM-meju) and the other that prepared by modified conventional method (MCM-meju), were made and compared their characteristics. The former made of cooked and crushed soybean with a brick shape was fermented at $15{\sim}20^{\circ}C\;and\;40{\sim}50%$ relative humidity (RH) for 30 days in koji room and the latter was fermented at $25{\sim}30^{\circ}C\;and\;80{\sim}90%$ RH seemingly being optimum for the growth of meju-organisms for the same period. The quality of MCM-meju as a raw material for the kanjang preparation was considered to be superior to that of CM-meju as the higher soluble nitrogen and total free amino acids content, the major factor for the evaluation of the quality of meju, were found in the former although the higher total nitrogen content and lower % weight loss were observed in the latter during meju preparation process. The quality of MCM-kanjang with higher total nitrogen, free amino acids, free sugars and the lower residual nitrogen content in cake after separation of kanjang was also found to be superior to that of CM-kanjang in sensory evaluation results.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.91-98
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• 2017

The purpose of this study is to provide a design and operation technical guideline for meeting the appropriate design criteria to bio-gasification facilities treating organic wastes. 9 anaerobic digestion facilities which is normally operated during the field survey and 14 livestock manure farms were selected for precision investigation. the physicochemical analysis was performed on the moisture and organic contents, nutrients composition (carbohydrate, fat, protein), volatile fatty acids (VFAs), and nitrogen, etc. Volatile solids (VS) of organic wastes brought into the bio-gasification facilities were 2.81 % (animal manure only) and 5.92 % (animal manure+food waste), respectively. Total solids (TS) reults of samples from livestock farms were 5.6 % in piglets and 11~13 % in other kinds of breeding pigs. The actual methane yield based on nutrients contents was estimated to $0.36Sm^3CH_4/kgVS$ which is equivalent to 72 % of theoretical methane yield value. The optimum mixing ratio depending on the effect of the combined bio-gasification was obtained through the continuous stirred-tank reactor (CSTR) which is operated at different mixing ratio of swine manure and food waste leachate. The range of swine manure and food waste leachate from 60:40 to 40:60 were adequate to the appropriate conditions of anaerobic digestion; less than 100 gTS/, more than alkalinity of 1 gCaCO3/L, C/N ratio 12.0~30.0, etc.

• Journal of Applied Biological Chemistry
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• v.52 no.4
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• pp.205-211
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• 2009

This study was carried out to acquire basic data for industrial production of Korean traditional kanjang (soy sauce). Five types of meju, $23{\times}11{\times}12$ ($L{\times}W{\times}H$, cm), $23{\times}11{\times}7$, $15{\times}11{\times}7$, $11{\times}11{\times}6$, $11{\times}11{\times}6$ (made a hole $\varphi$ 1.5 cm) were prepared. The temperature and humidity of meju preparation were $15{\sim}20^{\circ}C$ and 40~50% respectively. The smaller size of meju, the lower free amino acid and non-volatile organic acid content of that. And, two types of meju, conventional method (CM-meju, the temperature and humidity were prepared at $15{\sim}20^{\circ}C$ and 40~50% of relative humidity) and improved method(IM-meju, the temperature and humidity were prepared at $25{\sim}30^{\circ}C$ and 80~90% of relative humidity) for kanjang production were prepared. There was no difference of total nitrogen content and soluble nitrogen content in the size of meju. In total free amino acid content and total free sugar content, IM-meju was the higher than CM-meju. So, the quality of IM-meju was better than that of CM-meju.

• Korean Journal of Food Science and Technology
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• v.29 no.4
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• pp.790-799
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• 1997

The purpose of this study is to investigate the effects of yeast addition as starter on kimchi fermentation. The strains used as starter were Saccharomyces sp. YK-17 and Saccharomyces fermentati YK-19 isolated from kimchi, grew under anaerobic condition and low temperature, which showed the acid and base resistances. Chemical and microfloral changes, as well as the sensory properties of starter added kimchi during fermentation were compared with the control fermented without starter. The acidity of kimchi juice was lower and pH was higher in starter added kimchi than the control. Particularly addition of S. fermentati YK-19 prolonged the optimally fermented period (pH 4.0, acidity $0.6{\sim}0.8%$) up to more than 63%. The content of lactic acid, the major non-volatile organic acid in kimchi, was increased rapidly followed by S. sp. YK-17 and S. fermentati YK-19 group. The microfloral changes were found a little different among the samples. Among the microorganisms, Leuconostoc sp. and Lactobacillus sp. showed highest change, and Streptococcus sp. and Pediococcus sp. showed ralatively low change. The growth of Lactobacillus sp. which was the main acidifing microorganism was inhibited by starter addition, particularly by S. fermentati YK-19. The sensory characteristics of acidic and moldy flavor were significantly reduced by the addition, while fresh flavor was increased in starter added group.

• Journal of Soil and Groundwater Environment
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• v.10 no.2
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• pp.35-43
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• 2005

Bioslurping combines the three remedial approaches of bioventing, vacuum-enhanced free-product recovery, and soil vapor extraction. Bioslurping is less effective in tight (low-permeability) soils. The greatest limitation to air permeability is excessive soil moisture. Optimum soil moisture is very soil-specific. Too much moisture can reduce air permeability of the soil and decrease its oxygen transfer capability. Too little moisture will inhibit microbial activity. So Modified Fenton reaction as chemical treatment which can overcome the weakness of Bioslurping was experimented for simultaneous treatment. Although the diesel removal efficiency of SVE process increased in proportion to applied vacuum pressure, SVE process was difficulty to remediation quickly semi- or non-volatile compounds absorbed soil strongly. And SVE process had variation of efficiency with distance from the extraction well and depth a air flow form of hemisphere centering around the well. Below 0.1 % hydrogen peroxide shows the potential of using hydrogen peroxide as oxygen source but the co-oxidation of chemical and biological treatment was impossible because of the low efficiency of Modified Fenton reaction at 0.1 % (wt) hydrogen peroxide. NTA was more efficiency than EDTA as chelating agent and diesel removal efficiency of Modified Fenton reaction increased in proportion to hydrogen peroxide concentration. Hexadecane as typical aliphatic compound was removed less than Toluene as aromatic compound because of its structural stability in Modified Fenton reaction. What minimum 10% hydrogen peroxide concentration has good remediation efficiency of diesel contaminated groundwater may show the potential use of Modified Fenton reaction after bioslurping treatment.