• Title/Summary/Keyword: microbial content

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Changes in Quality of Crown Daisy and Kale Washed with Cooled Electrolyzed Acid Water during Storage (저온처리 전해산화수로 세정한 쑥갓과 케일의 저장중 품질변화)

  • 정승원;정진웅;이승현;박노현
    • Food Science and Preservation
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    • v.6 no.4
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    • pp.417-423
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    • 1999
  • Quality changes of crown daisy and kale were investigated during storage at 10$^{\circ}C$ after washing with cooled electrolyzed acid water at 3 times in 2 min. Total count and coliform count of crown daisy and kale after immersion in electrolyzed acid water were decreased to 1/130 and 1/1,170 of non-immersed crown daisy and to l/870 and l/470 of non-immersed kale. However total count and coliform count were increased to the similar levels of non-immesed and tap water immersed one after 6 days of storage. Weight loss of crown daisy and ka1e were lower than others for 3 days of storage but higher than that of one after that time. Decay rate of crown daisy and kale immersed electrolyzed acid water showed lower than that of non-immersed and tap water immersed one for 6 days. In case of kale, rupture strength was higher than others at just after immersion and showed similar values after initial storage period. Color value of both crown daisy and kale showed high L, b and low a value in the order of electrolyzed acid water, tap water and non-treatment. Chlorophyll content of crown daisy and kale were lower than those of others just after immersion in electrolyzed acid water, but showed rapid reduction in the order of non-treatment. tap water and electrolyzed acid water after 6 days. Overall organoleptic properties of crown daisy and kale in immersion electrolyzed acid water were higher than those of others.

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Changes in Soil Biota Affected by the Application of Organic Materials in Reclaimed Upland and Paddy-converted Soils Cultivated with Korea Ginseng (개간 및 답전윤환 인삼재배지에서 유기물처리에 따른 토양생물상 변화)

  • Eo, Jin-U;Park, Kee-Choon;Yeon, Byung-Ryul
    • Korean Journal of Soil Science and Fertilizer
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    • v.44 no.5
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    • pp.872-877
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    • 2011
  • Cultivation of Korea ginseng in newly reclaimed and paddy-converted fields has been increasing, and evaluation of organic amendment effectiveness is needed in the two soil types. Soil organisms influence organic matter decomposition, and their responses to applications of organic matter were studied. De-oiled cake and compost were applied at $20Mg\;ha^{-1}$ and $40Mg\;ha^{-1}$ in both soil types. Changes in microflora were assessed by analyzing phospholipid fatty acid (PLFA). The abundance of nematodes and microarthropods was measured. Microbial PLFA indicators for microorganisms and microarthropod abundance were greater in reclaimed upland than in paddy-converted soil. There were few differences in the microflora and fauna of reclaimed uplands, regardless of treatment. In paddy-converted soil, the abundance of Oribatida was increased by the application of compost at $20Mg\;ha^{-1}$ and was correlated with PLFA indicators of fungi. The results suggested a minimal influence of organic amendments in reclaimed upland, because the organic matter content and abundance of soil organisms are low in mineral soils. In paddy-converted soil, the effects of organic amendment differ among different soil organisms, and soil properties are important mediators of the effect.

Effects of the Physicochemical Properties of Lignocellulosic Artificial Soil Containing Bacillus subtilis on the Growth of Lespedeza cyrtobotrya (Bacillus subtilis가 함유된 목질계 인공토양의 물리·화학적 특성이 참싸리 생육에 미치는 영향)

  • Kim, Ji-Su;Jung, Ji young;Ha, Si Young;Yang, Jae-Kyung
    • Journal of the Korean Wood Science and Technology
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    • v.47 no.4
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    • pp.393-407
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    • 2019
  • In this study, we prepared lignocellulosic artificial soil that contains Bacillus subtilis (peat moss/perlite/ steam-exploded oak wood/microbial culture = 3:1:3:3, w/w/w/w) for use in the restoration of damaged soil areas. The prepared lignocellulosic artificial soil was mixed with soil at ratios of 0%, 25%, 50%, 75%, and 100%. These mixed soils were then applied to fields, and the resultant physicochemical properties and their effects on the plant growth of Lespedeza cyrtobotrya were observed. The mixture of the prepared artificial soils (mixed at ratios of 25%-100%) with soil had a bulk densities of <$0.04g/cm^3$, porosities of >85%, pH values between 4.3 and 4.7, electrical conductivities of <0.5 dS/m, C/N ratios between 15.0 and 26.5, organic matter content between 23.6% and 43.2%, and bacterial densities between $157{\times}10^6$ and $624{\times}10^6CFU/g$. In addition, the prepared artificial soils mixed with soil at ratios of 25%-50% exhibited higher plant growth rates for L. cyrtobotrya compared with the control. Overall, we identified positive correlations between the plant growth of L. cyrtobotrya and soil bulk density, porosity, water-holding capacity, C/N ratio, organic matter, and bacterial densities.

Antioxidant and Antimelanogenic Effects of Stevia rebaudiana Flower Extract

  • So, Gyeongseop;Lee, Sung Ryul;Kim, Sung Hyeok;Ha, Chang Woo;Park, Yuna;Jang, Sohee;Bak, Jong Phil;Koo, Hyun Jung;Sohn, Eun-Hwa
    • Korean Journal of Plant Resources
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    • v.32 no.3
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    • pp.220-227
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    • 2019
  • Stevia rebaudiana (Asteraceae), a perennial plant, has been used as a low-calorie sweetener and is being developed as a therapeutic agent for diabetes, hypertension, myocardial diseases, and microbial infections. Despite the common use of its leaves and stem, the bioavailability of the components present in S. rebaudiana flowers, when used as ingredients of cosmetics, has not been well investigated. Herein, we investigated the antioxidative and antimelanogenic effects of an aqueous extract of S. rebaudiana flowers (Stevia-F). Total flavonoid and phenolic content in Stevia-F were determined to be $8.64{\pm}0.23mg$ of quercetin equivalents/100 g and $631.5{\pm}2.01mg$ of gallic acid equivalents/100 g, respectively. The $IC_{50}$ values of Stevia-F for reducing power, and 2,2-diphenyl-1-picryl-hydrazyl-hydrate radical, hydrogen peroxide, and nitric oxide scavenging activities were 5541.96, 131.39, 466.34, and $10.44{\mu}g/mL$, respectively. Stevia-F showed inhibitory effects on the tyrosinase ($IC_{50}=134.74{\mu}g/mL$) and ${\alpha}$-glucosidase ($IC_{50}=114.81{\mu}g/mL$) activities. No significant cytotoxicity of Stevia-F was observed in B16F10 cells, treated with up to $100{\mu}g/mL$ of the extract for 24 and 48 h (p > 0.05). Stevia-F ($1-100{\mu}g/mL$) suppressed ${\alpha}$-melanocyte stimulating hormone-induced melanin production in B16F10 cells (p < 0.05) and also inhibited the cellular tyrosinase activity (p < 0.05). Overall, our results show that Stevia-F possesses potential for inhibiting tyrosinase and ${\alpha}$-glucosidase activities and has significant antioxidant capacity. The antimelanogenic potential of Stevia-F should extend the usage of S. rebaudiana flowers in the development of skin-whitening products.

Seasonal Change in the Quality Characteristics of Commercial Kimchi (국내 유통 김치의 계절별 품질특성 변화)

  • Lee, Jae Yong;Cheon, Seon Hwa;Kim, Su-Ji;Lee, Hee-Min;Lee, Hae-Won;You, Su-Yeon;Yoon, So Ra;Hwang, In Min;Jung, Ji-Hye;Kim, Sung Hyun
    • Journal of the Korean Society of Food Culture
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    • v.34 no.2
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    • pp.224-232
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    • 2019
  • This study evaluated the physicochemical and microbial quality characteristic of seasonal commercial kimchi for hygienic safety levels. The pH of seasonal commercial kimchi was 3.84-6.36 and the titratable acidity and salinity of the samples were 0.21-1.16 and 1.19-1.54%, respectively. The content of nitrate and nitrite in the commercial kimchi were lower in the spring and summer, which was affected by acidic condition of the kimchi depending on fermentation. Heavy metal contents in commercial kimchi are not an issue because they were detected only at very low levels. The total aerobic bacteria and coliforms counts ranged from 5.25 to 8.44 Log CFU/g and 0.00 to 5.08 Log CFU/g, respectively. The total aerobic bacteria and coliforms were detected more in summer than in the other seasons. E. coli was detected in three of the samples tested. Food-borne pathogens were not detected in any of the samples except for B. cereus. B. cereus was detected in the fall in more than 70% of samples. These results suggest that commercial kimchi distributed in the fall maintain the quality properties and the microbiological safety of kimchi compared to the other seasons. Therefore, further studies as an effective distribution system for the particular seasons will be needed to guarantee the hygienic safety levels of commercial kimchi required by the consumers.

Energy utilization, nutrient digestibility and bone quality of broiler chickens fed Tanzania-type diets in different forms with enzymes

  • Chang'a, Edwin Peter;Abdallh, Medani Eldow;Ahiwe, Emmanuel Uchenna;Al-Qahtani, Mohammed;Mbaga, Said;Iji, Paul Ade
    • Journal of Animal Science and Technology
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    • v.61 no.4
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    • pp.192-203
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    • 2019
  • A study was conducted to determine the influence of feed form and microbial enzyme supplementation on energy utilization, bone quality, and amino acid and mineral digestibility of broiler chickens. Four hundred and eighty Ross 308, day-old broiler chickens were randomly assigned to eight diets formulated from commonly used ingredients in Tanzania. A 2 (pellet or mash) ${\times}$ 4 (control, Axtra XB, Quantum Blue (QB) and Axtra XB + QB enzyme) factorial array in a completely randomized design having six replicates per treatment (10 birds per replicate) was used. Birds were raised in climate-controlled rooms in a 3-phase; starter (0-10 days), grower (11-24 days) and finisher (25-35 days). Apparent metabolizable energy (AME), metabolizable energy intake, net energy of production, energy retained as protein (REp), and efficiency of metabolizable energy use for energy and protein retention were higher (p < 0.05) in birds fed pelleted diets. The AME and REp was higher (p < 0.05) with enzyme supplementation. Ash content, weight, length, width and breaking strength of tibia bones were highest (p < 0.05) in birds on pelleted diets. Tibia bone traits were improved (p < 0.05) when enzymes were included, particularly in a combination of QB and Axtra XB. However, potassium, magnesium, and zinc contents were highest (p < 0.05) when QB was supplemented. Digestibility of all amino acids was higher (p < 0.05) in birds supplied with pellets and with enzyme supplementation for most amino acids, except for serine. There was a positive interaction (p < 0.05) between feed form and enzymes on lysine and phenylalanine digestibility. Digestibility of Ca, P, K, S, Zn, and Fe was higher (p < 0.05) in birds fed pelleted diets, while those on mashed diets had higher (p < 0.05) digestibility of Cu and B. The digestibility of P, K, and Zn was highest (p < 0.001) when QB was added, while Ca, P, S, and B digestibility was highest when a combination of Axtra XB + QB was applied. Pelleted diets with or without enzymes improved energy utilization, digestibility of amino acids, and minerals, and increased bone strength in broiler chickens.

Effects of Lactic Acid Bacteria Inoculants on Fermentation of Low Moisture Fresh Rice Straw Silage at Different Storage Periods

  • Kuppusamy, Palaniselvam;Soundharrajan, Ilavenil;Park, Hyung Soo;Kim, Ji Hea;Kim, Won Ho;Jung, Jeong Sung;Choi, Ki Choon
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.39 no.3
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    • pp.165-170
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    • 2019
  • The purpose of this study was to analyze the effectiveness of different storage periods of lactic acid bacteria (LAB)-fermented low moisture fresh rice straw silage. The low moisture fresh rice straw sample was inculcated with LAB and stored for different storage periods such as 45, 90, and 365 days, respectively. The low moisture fresh rice straw (LMFRS) silage inoculated with LAB exhibited reduction in pH throughout the fermentation as compared with the control (P<0.05). The lactic acid content was increased at the late fermentation period (90 and 365 days, respectively) in LAB inoculated LMFRS silage as compared with the control (P<0.05). In contrast, the acetic acid and butyric acid concentrations were slightly reduced in the LAB inoculated LMFRS silage sample at 90 and 365 days fermentation, respectively. Meanwhile, the non-inoculated LMFRS silage showed higher amounts of acetic acid and butyric acid at an extended fermentation with low bacterial population as compared with the LAB inoculated LMFRS silage. However, lactic acid concentration was slightly high in the non-inoculated LMFRS silage at early 45 days fermentation. Additionally, the nutrient profile such as crude protein (CP), acid detergent fibre (ADF), neutral detergent fibre (NDF), and total digestibility nutrients (TDN) were not significantly different in control and LAB inculcated samples during all fermentation. Though, the microbial population was greater in the LAB inoculated LMFRS silage as compared with the control. However, the massive population was noted in the LAB inoculated LMFRS silage during all fermentation. It indicates that the inoculated LAB is the main reason for increasing fermentation quality in the sample through pH reduction by organic acids production. Overall results suggest that the LAB inoculums are the effective strain that could be a suitable for LMFRS silage fermentation at prolonged days.

The Study of Fermented Chestnut Meal and Its Rumen Fermentation Characteristics (밤의 부위별 발효사료 제조 및 이들의 반추위 내 발효특성에 관한 연구)

  • Joo, Young-Ho;Kim, Dong-Hyeon;Lee, Hyuk-Jun;Lee, Seong-Shin;Paradhipta, Dimas H.V.;Ha, Chang-Ju;Kim, Sam-Churl
    • Journal of Environmental Science International
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    • v.28 no.6
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    • pp.527-533
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    • 2019
  • The aim of present study was to investigate the effect of three types of Chestnut Meals (CM) on chemical composition and rumen fermentation characteristics of the fermented diet. The inoculants consisted of Lactobacillus acidophilus, Bacillus subtilis, and Sacaromyces cerevisiae and were applied to three different types of CM; Whole Chestnut (WC), endodermis (EN), and kernel (KE). All types of CMs were ensiled at $39^{\circ}C$ for 0, 1, 2, 4, or 6 days. After ensiling, the fermented CMs were sub-sampled for laboratory assays. On day six of fermentation, counts of the lactic acid-producing Bacillus subtilis, and yeast were higher (P<0.05) in WC than in the other CM types. On day four, KE had higher (P<0.05) crude protein content but lower (P<0.05) neutral detergent fiber and acid detergent fiber contents than the other treatments. In terms of rumen digestibility, KE had the highest (P<0.05) in vitro digestibility of dry matter (IVDMD), neutral detergent fiber digestibility (IVNDFD), total volatile fatty acid (VFA), propionate, butyrate concentrations, and total gas volume, as well as the lowest (P<0.05) acetate concentration. On the other hand, EN had the highest (P<0.05) pH and ammonia-N concentration in the rumen. In the rumen, even though WC application produced the highest microbial count and fermentation characteristics, it did not have a beneficial effect on rumen digestibility. Therefore, this study concluded that application of KE could be recommended due to the observed improvements in IVDMD and IVNDFD.

Soil Carbon Storage in Upland Soils by Biochar Application in East Asia: Review and Data Analysis (바이오차를 이용한 밭 토양 탄소 저장: 동아시아 지역 연구 리뷰 및 데이터 분석)

  • Lee, Sun-Il;Kang, Seong-Soo;Choi, Eun-Jung;Gwon, Hyo-Suk;Lee, Hyoung-Seok;Lee, Jong-Mun;Lim, Sang-Sun;Choi, Woo-Jung
    • Korean Journal of Environmental Agriculture
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    • v.40 no.3
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    • pp.219-230
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    • 2021
  • BACKGROUND: Biochar is a solid material converted from agricultural biomass such as crop residues and pruning branch through pyrolysis under limited oxygen supply. Biochar consists of non-degradable carbon (C) double bonds and aromatic ring that are not readily broken down by microbial degradation in the soils. Due to the recalcitrancy of C in biochar, biochar application to the soils is of help in enhancing soil carbon sequestration in arable lands that might be a strategy of agricultural sector to mitigate climate change. METHODS AND RESULTS: Data were collected from studies on the effect of biochar application on soil C content conducted in East Asian countries including China, Japan and Korea under different experimental conditions (incubation, column, pot, and field). The magnitude of soil C storage was positively correlated (p < 0.001) with biochar application rate under field conditions, reflecting accumulation of recalcitrant black C in the biochar. However, The changes in soil C contents per C input from biochar (% per t/ha) were 6.80 in field condition, and 12.58 in laboratory condition. The magnitude of increment of soil C was lower in field than in laboratory conditions due to potential loss of C through weathering of biochar under field conditions. Biochar production condition also affected soil C increment; more C increment was found with biochar produced at a high temperature (over 450℃). CONCLUSION: This review suggests that biochar application is a potential measures of C sequestration in agricultural soils. However, as the increment of soil C biochar was affected by biochar types, further studies are necessary to find better biochar types for enhanced soil C storage.

Monitoring of Pathogenic Bacteria, Heavy Metals, and Pesticide Residues in Commercial Edible Dry Flowers (시판 23종 꽃차의 유해세균, 중금속 및 잔류농약 평가)

  • Lee, Yun-Seo;Lee, Dong-Hee;Hwang, Eun-Kyung;Sohn, Ho-Yong
    • Journal of Life Science
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    • v.32 no.6
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    • pp.438-446
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    • 2022
  • Some flowers have a high sensual appeal owing to their unique shape, color, smell, and taste and have been used as functional food and oriental medicine. Recently, edible dry flowers (EDFs) have attracted social attention as noble sources of functional teas. In this study, for the risk assessment of EDFs, pathogenic bacteria, heavy metals, and pesticide residues were monitored in 23 types of commercial EDF. No Enterobacteria spp. and Listeria spp. were found in all EDF products. However, common aerobic bacteria (3.24~3.85 Log CFU/g) were found in EDF, namely, Pueraria lobata, Chamaemelum nobile, Acacia decurrens, Rhododendron mucronulatum Turcz, Oenothera lamarckiana, Brassica napus, and Prunus serrulata. Staphylococcus aureus was found in 11 and Salmonella sp. was found in 8 of the 23 EDFs. Considering the cold extraction of EDF for tea and beverages, the regulation of pathogenic bacteria in EDFs is necessary. No heavy metals such as Pb, Cd, Co, Cr, Cu, Ni, and As were found in all EDFs, except the dry flower of Hemerocallis fulva, which contained Pb at 0.08 ppm. Different pesticides and fungicides were found in EDFs, but their concentrations were very low (0.01~0.08 ppm) and below the maximal residue level. Only the dry flower of Chrysanthemum morifolium had a high content of chlorpyrifos (0.215 ppm), which is long-lasting pesticide. Our results suggest that the establishment of EDF regulations for pesticide residue, culture separation between edible and garden flowers, and guidelines for preventing pathogenic microbial contamination are necessary.