• Title/Summary/Keyword: Microbial water quality

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Development of Carbonization Technology and Application of Unutilized Wood Wastes(II) - Carbonization and it's properties of wood-based materials - (미이용 목질폐잔재의 탄화 이용개발(II) - 수종의 목질재료 탄화와 탄화물의 특성 -)

  • Kong, Seog-Woo;Kim, Byung-Ro
    • Journal of the Korean Wood Science and Technology
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    • v.28 no.2
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    • pp.57-65
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    • 2000
  • Objective of research is obtain fundamental data of carbonized wood wastes for soil condition, de-ordorization, absorption of water, carrier for microbial activity, and purifying agent for water quality of river. The carbonization technique and the properties of carbonized wood wastes(wood-based materials) were analyzed. Proximate analysis showed the wood-based materials contains 0.37~2.27% ash, 70~74% volatile matter, and 17~20% fixed carbon. As carbonization temperature was increased, the charcoal yield was decreased. However, no difference in charcoal yield was found due to time increase. The specific gravity after the carbonization decreased about 30~40% comparing to green wood. The charcoal had 1.08~4.18% ash, 5.88~13.79% volatile matter, and 80.15~90.94% fixed carbon. The pH of plywood and particleboard(pH 9 at $400^{\circ}C$, pH 10 at $600^{\circ}C$ and $800^{\circ}C$) made charcoals was higher than that of fiberboard. The water-retention capacity was not affected by the carbonization temperature and time. The water-retention capacity within 24h was about 2~2.5 times of sample weight, and the Equilibrium moisture content(EMC) became 2~10% after 24h. EMC of charcoal from the thinned trees were 9.40~11.82%($20^{\circ}C$, RH 90%), 6.87~7.61%($20^{\circ}C$, RH 65%), and 1.69~2.81%($20^{\circ}C$, RH 25%). EMC of charcoal from the wood-based materials under $20^{\circ}C$, relative humidity(RH) 90% was similar to EMC of charcoal from the thinned trees(9~11 %). However, under $20^{\circ}C$, RH 25.65%, EMC of charcoal from the wood-based materials were higher(2~3%) than EMC of charcoal from the thinned trees. Every charcoal from the wood-based materials fulfilled the criteria in JWWA K 113-1947.

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Preparation and Keeping Quality of Vacuum Packed Seasoned-Dried Sardine (진공포장 정어리 조미건제품의 제조 및 품질안정성)

  • LEE Eung-Ho;KIM Jin-Soo;KIM Han-Ho;LEE Jin-Kyung;OH Kwang-Soo;KWON Chil-Sung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.19 no.1
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    • pp.52-59
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    • 1986
  • As one of trials to process instant sardine foods which can be preserved at room temperature, three kinds of products were prepared as seasoned-dried product (control, C), liquid smoked seasoned-dried product(S) and antioxidant treated seasoned-dried product(E), and their processing conditions and quality stability during storage were examined. Raw sardines were dressed, steamed and then filleted. The sardine fillets were seasoned with the mixed seasoning solution containing $28.0\%$ of sorbitol, $14.0%$ of sugar, $5.6\%$ of table salt, $1.8\%$ of monosodium glutamate, $0.6\%$ of garlic powder and $50.0\%$ of water at $5^{\circ}C$ for 15 hours, and dipped for 45 seconds in $10\%$ Smoke-EZ solution. After liquid smoking, the seasoned and liquid smoked sardine fillets were dried at $45^{\circ}C$ for 4 hours, vacuum packed in laminated plastic film bag(polyester/casted polypropylene= $12{\mu}m/70{\mu}m,\;15{\times}16cm$), and finally pasteurized in water at $95^{\circ}C$ for 30 minutes. The results obtained from chemical and microbial experiments during storage are as follows : the moisture contents, water activity and pH of the products showed little change, and VBN of them slightly increased during storage. The TBA value and POV of the products (E, S) were lower than those of control product(C) considerably. In color values, L value (linghtness) decreased while a and b value (red and yellow) revealed a tendency to increase during storage. The fatty acid composition of the products were similar to those of raw sardine, the predominant fatty acids were 16:0, 20:5, 18:1 and 22:6. The products (E, S) have a good preservative effect on highly unsturated fatty acids during storage. Viable cell counts of those products were negative and histamine contents were less than 2.0 mg/100 g. Among the texture profiles, hardness, elasticity and cohesiveness of the products slightly decreased during storage. Judging from the sensory evaluations, liquid smoked seasoned-dried product(S) was the most desirable, and the products could be preserved in good condition for 40 days at $25{\pm}3^{\circ}C$.

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Meat Quality and Storage Characteristics of Finishing Pigs by Feeding Stevia and Charcoal (스테비아와 숯이 급여된 비육돈의 육질 및 저장특성)

  • Lee, Jae-Joon;Park, Sung-Hyun;Jung, Dong-Soon;Choi, Yang-Il;Choi, Jung-Soek
    • Food Science of Animal Resources
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    • v.31 no.2
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    • pp.296-303
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    • 2011
  • This study was conducted to determine the effects of stevia (Stevia rebaudiana Bertoni) and charcoal supplementation on meat quality traits in finishing pigs. A total of 420 pigs (LYD) were randomly allocated into seven treatments with three replications. The dietary treatments were T1 (control, basal diet), T2 (basal diet+0.3% stevia), T3 (basal diet+0.6% stevia), T4 (basal diet+0.3% charcoal), T5 (basal diet+0.6% charcoal), T6 (basal diet+0.3% stevia+0.3% charcoal), and T7 (basal diet+0.6% stevia+0.6% charcoal). Pigs were slaughtered conventionally on each marketing day and chilled overnigth. At 24 h postmortem, the Longissimus muscle from left side between the 6th and 14th rib was removed for the meat quality traits. The T6 group showed a higher pH, water holding capacity (p<0.05), and lower drip loss (p<0.05) than those in the T1 group. The T6 group showed lower (p<0.05) $L^*$ (lightness) and $b^*$ (yellowness) values and higher $a^*$ (redness) color value than those in the T1 group, resulting in a redder surface meat color. In the subjective evaluation, marbling and color scores improved in the T6 group compared to those in the other treatments. In the panel test, the T6 group tended to have higher tenderness and juiciness scores than those in the T1 group. In the storage characteristics, all treatments showed similar 2-thiobarbituric acid and volatile basic nitrogen values as well as total microbial counts during 7 d of cold storage. As a result, dietary supplementation with 0.3% stevia and 0.3% charcoal showed the highest meat quality traits and storage characteristics in finishing pigs.

Effect of Electrolyzed Water and Hot-Air-Drying with UV for the Reduction of Microbial Populations of Undaria pinnatifida (전해수 수세, 열풍건조 및 자외선 조사에 의한 미역의 미생물 감소 효과)

  • Bark, Si-Woo;Kim, Koth-Bong-Woo-Ri;Kim, Min-Ji;Kang, Bo-Kyeong;Pak, Won-Min;Kim, Bo-Ram;Ahn, Na-Kyung;Choi, Yeon-Uk;Cho, Young-Je;Ahn, Dong-Hyun
    • Microbiology and Biotechnology Letters
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    • v.43 no.1
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    • pp.38-44
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    • 2015
  • This study was conducted to investigate the effects of electrolyzed water (EW) and hot-air-drying with ultraviolet light (UV) to reduce coliform bacteria of Undaria pinnatifida (UP). The UP was washed in the order of 15% EW, tap water (TW), and distilled water (DW) under following conditions: 15% EW for 10 min (washing: 1 time), TW for 1 min, and DW for 10 min (washing: 5 times). Viable cells, coliform, and mold counts were at 102-103 CFU/g in untreated samples. After EW treatment, viable cells, coliform, and molds were not detected in whole samples or on the surface of UP. But, after hot-air-drying at 48°C for 48 h, the number of viable cells, coliform, and molds were 101-105 CFU/g. After hot-air-drying at 48°C for 48 h with UV (12-48 h), viable cells, coliform, and molds were not detected in whole samples or on the surface of UP. In respect of color value, there were no significant changes. In sensory evaluation, the UP with hot-air-drying with UV (12 h) had the highest score in overall preference among UV treatment groups. These results suggest that the treatments at 15% EW for 10 min and hot-air-drying at 48°C for 48 h with UV (12 h) were effective to reduce coliform bacteria of the dried Undaria pinnatifida.

Quality Characteristics of the Meat Products Reached Expiration Date in Korean Market (유통기한이 임박한 한국산 식육제품의 품질 특성)

  • Yim, Dong-Gyun;Yang, Mi Ra;No, Gun Ryoung;Choi, Dong Sun;Jang, Hyeon Myeong;Kim, Tae Yeon;Jo, Jang Woong;Yang, Seung Chang;Kim, Sam Woong;Kim, Il-Suk
    • Journal of agriculture & life science
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    • v.50 no.4
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    • pp.169-177
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    • 2016
  • This study was carried out to compare microbiological and hygienic quality characteristics of the products reached expiration date among meat products distributing in markets. A total of 20 meat products(6 hams, 3 bacons and 11 sausages) were examined for analyses of pH, Aw, TBARS, VBN, total aerobic microbial counts, and meat colors. The pH values of samples were between 5.33 and 6.59. The water activity (Aw) of samples ranged 0.90-0.93. TBARS and VBN values of samples were 0.11-0.59 and 2.37~14.75, respectively. The contaminated levels of total aerobic bacteria were less than 2.80 CFU/g. In meat color, L*, a*, and b* values of samples were in the range of 56-72, 5.2-34 and 0.7-16, respectively. It is suggested that the quality difference of meat products is attributed to the different additives and manufacturing processes. Therefore, we suggest that the results of this study are not only applied for evaluation of the microbiological and hygienic safety but also served as fundamental information for re-establishing the shelf-life of meat products.

Assessment of Methane Production Rate Based on Factors of Contaminated Sediments (오염퇴적물의 주요 영향인자에 따른 메탄발생 생성률 평가)

  • Dong Hyun Kim;Hyung Jun Park;Young Jun Bang;Seung Oh Lee
    • Journal of Korean Society of Disaster and Security
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    • v.16 no.4
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    • pp.45-59
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    • 2023
  • The global focus on mitigating climate change has traditionally centered on carbon dioxide, but recent attention has shifted towards methane as a crucial factor in climate change adaptation. Natural settings, particularly aquatic environments such as wetlands, reservoirs, and lakes, play a significant role as sources of greenhouse gases. The accumulation of organic contaminants on the lake and reservoir beds can lead to the microbial decomposition of sedimentary material, generating greenhouse gases, notably methane, under anaerobic conditions. The escalation of methane emissions in freshwater is attributed to the growing impact of non-point sources, alterations in water bodies for diverse purposes, and the introduction of structures such as river crossings that disrupt natural flow patterns. Furthermore, the effects of climate change, including rising water temperatures and ensuing hydrological and water quality challenges, contribute to an acceleration in methane emissions into the atmosphere. Methane emissions occur through various pathways, with ebullition fluxes-where methane bubbles are formed and released from bed sediments-recognized as a major mechanism. This study employs Biochemical Methane Potential (BMP) tests to analyze and quantify the factors influencing methane gas emissions. Methane production rates are measured under diverse conditions, including temperature, substrate type (glucose), shear velocity, and sediment properties. Additionally, numerical simulations are conducted to analyze the relationship between fluid shear stress on the sand bed and methane ebullition rates. The findings reveal that biochemical factors significantly influence methane production, whereas shear velocity primarily affects methane ebullition. Sediment properties are identified as influential factors impacting both methane production and ebullition. Overall, this study establishes empirical relationships between bubble dynamics, the Weber number, and methane emissions, presenting a formula to estimate methane ebullition flux. Future research, incorporating specific conditions such as water depth, effective shear stress beneath the sediment's tensile strength, and organic matter, is expected to contribute to the development of biogeochemical and hydro-environmental impact assessment methods suitable for in-situ applications.

Characteristics and Preservation of Sulgi Added with Onion Juice (양파즙 첨가 설기의 특성과 저장 효과)

  • Son, Du-Ho;Hwang, Yong-Il
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.5
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    • pp.677-683
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    • 2012
  • The characteristics and preservation of sulgi added with 0, 1, 3, and 5% onion juice were investigated during storage at $4^{\circ}C$, $18^{\circ}C$, and $30^{\circ}C$. The pH of sulgi added with onion juice was lower than that of sulgi without onion juice and showed higher pH levels at $4^{\circ}C$ than at $18^{\circ}C$ or $30^{\circ}C$. Hardness of sulgi gradually decreased with higher volume of onion juice. Sulgi added with onion juice had higher values of lightness and yellowness than those of the control, whereas redness value was lower. Water activity of sulgi increased upon addition of onion juice. Further, addition of onion juice inhibited growth of aerobic bacteria and mold on sulgi, and the highest suppression of microbial growth was observed at $4^{\circ}C$ compared to other storage temperatures. In the sensory evaluation, color, flavor, after swallowing, and overall quality were all higher in sulgi containing 1% onion juice, but there were no significant differences compared to control sulgi. These results imply that addition of onion juice to sulgi has health and functional benefits and also extends the self-life of sulgi.

Quality Characteristics of Makgeolli Added with Kiwifruit (Actinidia deliciosa) (키위를 첨가한 막걸리의 품질특성)

  • Kim, Eunkyung;Chang, Yoon Hyuk;Ko, Jae Youn;Jeong, Yoonhwa
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.11
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    • pp.1821-1828
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    • 2013
  • This study was conducted to investigate the physicochemical and microbial properties of Makgeolli supplemented with kiwifruit (Actinidia deliciosa). Four hundred grams of kiwifruit were added to 3.1 L of distilled water, followed by 2.0 kg of rice, 40.0 g of Nuruk, and 14.0 g of yeast. The mixed rice solution was then fermented at $28^{\circ}C$ for 6 days to prepare the kiwifruit Makgeolli. The pH values of the kiwifruit Makgeolli decreased from 5.31 to 4.37, but the total acidity values increased from 0.05 to 0.34% during fermentation. The total viable cells ($3.18{\times}10^7$ and $2.88{\times}10^7$, respectively), lactic acid bacteria ($1.51{\times}10^6$ and $1.50{\times}10^6$, respectively), and yeast counts ($1.96{\times}10^7$ and $1.90{\times}10^7$, respectively) of the kiwifruit Makgeolli and control were similar throughout the fermentation process. Glucose was the major free sugar in the control and kiwifruit Makgeolli and significantly decreased during fermentation. Succinic acid was the highest organic acid in both the control (24.6 mg/mL) and kiwifruit Makgeolli (26.3 mg/mL). In a volatile compound analysis, 3-methyl-1-butanol, 2-methyl-1-propanol and ethyl acetate were the major volatile compounds in the kiwifruit Makgeolli.

Ginsenosides Composition and Antioxidant Activities of Fermented Ginseng Soymilk (인삼 첨가 발효두유의 사포닌 조성 및 항산화 활성)

  • Lee, Lan-Sook;Jung, Kyung Hee;Choi, Ung-Kyu;Hong, Hee-Do;Kim, Young-Chan
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.42 no.10
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    • pp.1533-1538
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    • 2013
  • The objective of this study is to select an effective microbial strain to enhance the sensory qualities and functionalities of fermented ginseng soymilk. For this purpose, soybean were ground with water extracts of ginseng and fermented with five Lactobacillus strains. All strains grew well in ginseng soymilk, and viable cell counts reached greater than 8 log CFU/mL after 18 h of fermentation. The contents of total ginsenosides were higher in soymilk fermented with L. casei ATCC 393 than those in the other strains. The sensory qualities of the fermented soymilk were observed to increase with the intensity of sourness and showed the best sensory acceptability of soymilk fermented with L. kefir ATCC 35411. Moreover, the antioxidant activities, superoxide and hydroxyl radical scavenging activities were significantly enhanced by 2~4 and 4~5 times, respectively, compared to the non-fermented soymilk. In particular, the antioxidant activities of the fermented soymilk by L. kefir ATCC 35411 were the highest among the samples. This result suggests that soymilk fermented by L. kefir ATCC 35411 allowed obtaining a soymilk with enhanced sensory quality and antioxidant activity was able to contribute to the health benefit.

Improvement of Storaging Ability of Waxycorn by Retort Pouch Technique (레토르트 파우치 방법에 의한 찰옥수수의 저장성 향상)

  • Heo Nam-Kee;Kim Keyung-Dea;Choi Byoung-Gon;Kim Keyung-Hee;Min Hwang-Kee;Kwon Heuy-Jeong
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.50 no.spc1
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    • pp.147-151
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    • 2005
  • Retort pouch is widely used in food industry for a long-term preservation and safe food production. By applying retort pouch technique to waxycorn storage, the quality of waxycorn could be maintained and the storage expense could be saved during storage. Water activities(Aw) of retort waxycorn were below 0.80 except blanching treatment, and it is known that microbial propagation is subdued below 0.80. Commercial value of waxy corn was deteriorated when it was frozen quickly at $-40^{\circ}C$ before treating Retort due to obscurity of chromatocity, while the color change was not noticeable when it was treated with Retort at $121^{\circ}C$ for 10min. For all treatments, very small amounts of free sugar were detected, however, there were no significant differences between treatments. As storage period was longer, shelf lifes of waxy corn in control and waxy corn treated with blanching were more shortened when waxy corn was stored at $15,5^{\circ}C$ before Retort, while waxy corn with boiling treatment was not significantly different compared with that in storage in freezer.