• Title/Summary/Keyword: microbiology

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Effects of Various Humectants on Quality Properties of Pork Jerky (보습제 종류와 첨가수준이 돈육 육포의 품질특성에 미치는 영향)

  • Han, Doo-Jeong;Jeong, Jong-Youn;Choi, Ji-Hun;Choi, Yun-Sang;Kim, Hack-Youn;Lee, Mi-Ai;Lee, Eui-Soo;Paik, Hyun-Dong;Kim, Cheon-Je
    • Food Science of Animal Resources
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    • v.28 no.4
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    • pp.486-492
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    • 2008
  • We investigated the quality properties of pork jerky prepared with various humectants (Konjac, egg albumin, isolated soy protein). Jerky was prepared as follows; control with no humectants, treatments with 0.05, 0.1, and 0.2% humectants, respectively. Humectant treatments had higher drying yields of pork jerky than the control (p<0.05), Konjac treatment produced the the highest drying yields among the humectants tested. CIE a-and b-value were lowest in isolated soy protein treatments. b-value in 0.2% egg albumin treatments were higher than other treatments (p<0.05). Jerky water content increased as humectant content increased. Water activity (Aw) in 0.2% Konjac treatments was higher than controls and 0.05% Konjac (p<0.05). In textual profile evaluations, control samples had greater hardness, cohesiveness, gumminess, and chewiness values than other treatments, but very low springiness (p<0.05). Control had significantly (p<0.05) lower scores than the other treatments in sensorial texture, juiciness and overall acceptability. Based on our findings, we conclude that 0.05% Konjac was the most effective humectant among those we tested in this study.

Studies on the Rapid Discrimination of Yellow Pigments Colored on Yellow Croakers and Natural Yellow Pigment of Croakers (참조기의 천연색소와 인위적으로 착색된 황색색소류 판별법에 관한 연구)

  • Kim, Hee-Yun;Hong, Jin-Hwan;Kim, Dong-Sul;Han, Sang-Bae;Lee, Eun-Ju;Lee, Jeung-Seung;Kang, Kil-Jin;Chung, Hyung-Wook;Song, Kyung-Hee;Park, Hye-Kyung;Park, Jong-Seok;Kwon, Yong-Kwan;Chin, Myung-Shik;Park, Hee-Ok;Oh, Sae-Hwa;Shin, Il-Shik;Lee, Chang-Kook;Park, Hee-Yul;Ha, Sang-Chul;Jo, Jae-Sun
    • Korean Journal of Food Science and Technology
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    • v.34 no.6
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    • pp.977-983
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    • 2002
  • This study was performed to establish the precise and rapid method to distinguish croakers through the pigment analysis of colored imported white croakers for adultration. We surveyed the coloring behaviors, extraction test by water and organic solvent and using pigments such as targeting, curcumine, and azo dye products. The pigment of yellow croaker is not stained on wet cloth or tissue which is rubbed on epidermis of yellow croaker and was not eluted in water extraction test, while adulterated pigments were easily extracted by water and acetone, but edible diluted yellow, Yellow No. 4 and Yellow No. 5 were not extracted. Reactive pigment was detected easily by extraction with water and dispersed pigment was also detected by extraction test. As a result of discoloring characteristics of carotene having similar structure to yellow croaker and azo dye by oxidation and reduction, azo dyes were not discolored by oxidation with sodium percarbonate or peracetic acid but that were discolored by oxidation with Fenton reagent after 1hr and by hypochlorite promptly. On the other hand, carotenes were not discolored by sodium precarbonate and Fenton reagent but discolored by sodium hypochlorite after 2 hr and by peracetic acid promptly. Azo dyes were discolored by reduction with sodium hydrosulfite and sodium carbonate but carotenes were not discolored by these reagents. This discoloring test was applicable to detect adulterated pigments and other marine product.

EFFECT OF ROTATIONAL SPEED OF PROTAPERTM ROTARY FILE ON THE CHANCE OF ROOT CANAL CONFIGURATION (ProTaperTM로 근관성형시 회전 속도 변화가 근관형태에 미치는 영향)

  • Seo, Min-Chul;Jeon, Yoon-Jeong;Kang, In-Chol;Kim, Dong-Jun;Hwang, Yun-Chan;Hwang, In-Nam;Oh, Won-Mann
    • Restorative Dentistry and Endodontics
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    • v.31 no.3
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    • pp.179-185
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    • 2006
  • This study was conducted to evaluate canal configuration after shaping by $ProTaper^{TM}$ with various rotational speed in J-shaped simulated resin canals. Forty simulated root canals were divided into 4 groups, and instrumented using by $ProTaper^{TM}$ at the rotational speed of 250, 300, 350 and 400 rpm. Pre-instrumented and post-instrumented images were taken by a scanner and those were superimposed. Outer canal width, inner canal width, total canal width, and amount of transportation from original axis were measured at 1, 2, 3, 4, 5, 6, 7 and 8 mm from apex. Instrumentation time, instrument deformation and fracture were recorded. Data were analyzed by means of one-way ANOVA followed by Scheffe's test. The results were as follows 1. Regardless of rotational speed, at the $1{\sim}2mm$ from the apex, axis of canal was transported to outer side of a curvature, and at 3~6 mm from the apex, to inner side of a curvature. Amounts of transportation from original axis were not sienifcantly different among experimental groups except at 5 and 6 mm from the apex. 2. Instrumentation time of 350 and 400 rpm was significantly less than that of 250 and 300 rpm (p<0.01). In conclusion the rotational speed of $ProTaper^{TM}$ files in the range of $250{\sim}400rpm$ does not affect the change of canal configuration, and high rotational speed reduces the instrumentation time. However appearance of separation and distortion of Ni-Ti rotary files can occur in high rotational speed.

Effect of Swine Liquid Manure on Soil Chemical Properties and Growth of Rice (Oryza sativa L.) (양돈분뇨 발효액비 시용이 토양 화학성과 벼 (Oryza sativa L.) 생육에 미치는 영향)

  • Lee, Kyu-Hoi;Yoo, Jae-Hong;Park, Eun-Ju;Jung, Yeong-In;Tipayno, S.C.;Shagol, C.C.;Sa, Tong-Min
    • Korean Journal of Soil Science and Fertilizer
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    • v.43 no.6
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    • pp.945-953
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    • 2010
  • This study was conducted to evaluate the effect of swine liquid manure (SLM) on rice grown in Yeonggwang-gun in 2008. The treatments consisted of SLM and chemical fertilizer (CF) based on the recommended amount of nitrogen (11 kg N $10a^{-1}$). The Total N content of the SLM used was 2,881 mg $L^{-1}$. Plant height at the early stage of growth and tiller number were not significantly different between plots applied with swine liquid manure and those with chemical fertilizer in all areas. Plant height at the later stage of growth, lodging and yield were not significantly different between plots applied with swine liquid manure and those with chemical fertilizer in three areas (Baeksu, Gunnam, Beopseong). Plant height at the later stage of growth, as well as lodging were higher in SLM plots than in chemically fertilized plots in Yeonggwang and Yeomsan. However, grain yield was lower in SLM plots than in chemically fertilized plots in these areas. Soil organic matter content and exchangeable cations increased in the swine liquid manure applied plots. Moreover, heavy metal content did not increase in the plots treated with swine liquid manure. Further research to determine the suitable rate of swine liquid manure is needed to reduce lodging damage and to increase the yield and quality of rice.

Potential Contamination Sources on Fresh Produce Associated with Food Safety

  • Choi, Jungmin;Lee, Sang In;Rackerby, Bryna;Moppert, Ian;McGorrin, Robert;Ha, Sang-Do;Park, Si Hong
    • Journal of Food Hygiene and Safety
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    • v.34 no.1
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    • pp.1-12
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    • 2019
  • The health benefits associated with consumption of fresh produce have been clearly demonstrated and encouraged by international nutrition and health authorities. However, since fresh produce is usually minimally processed, increased consumption of fresh fruits and vegetables has also led to a simultaneous escalation of foodborne illness cases. According to the report by the World Health Organization (WHO), 1 in 10 people suffer from foodborne diseases and 420,000 die every year globally. In comparison to other processed foods, fresh produce can be easily contaminated by various routes at different points in the supply chain from farm to fork. This review is focused on the identification and characterization of possible sources of foodborne illnesses from chemical, biological, and physical hazards and the applicable methodologies to detect potential contaminants. Agro-chemicals (pesticides, fungicides and herbicides), natural toxins (mycotoxins and plant toxins), and heavy metals (mercury and cadmium) are the main sources of chemical hazards, which can be detected by several methods including chromatography and nano-techniques based on nanostructured materials such as noble metal nanoparticles (NMPs), quantum dots (QDs) and magnetic nanoparticles or nanotube. However, the diversity of chemical structures complicates the establishment of one standard method to differentiate the variety of chemical compounds. In addition, fresh fruits and vegetables contain high nutrient contents and moisture, which promote the growth of unwanted microorganisms including bacterial pathogens (Salmonella, E. coli O157: H7, Shigella, Listeria monocytogenes, and Bacillus cereus) and non-bacterial pathogens (norovirus and parasites). In order to detect specific pathogens in fresh produce, methods based on molecular biology such as PCR and immunology are commonly used. Finally, physical hazards including contamination by glass, metal, and gravel in food can cause serious injuries to customers. In order to decrease physical hazards, vision systems such as X-ray inspection have been adopted to detect physical contaminants in food, while exceptional handling skills by food production employees are required to prevent additional contamination.

Preservative Efficacies according to the Composition of 1, 3-Butylene Glycol and Alkane Diols in Cosmetics (화장품에서 1,3-부틸렌 글라이콜 및 알칸디올계 조성에 따른 방부력에 관한 연구)

  • Suh, Ji Young;Yun, Mid Eum;Lee, Ye Seul;Xuan, Song Hua;Park, Dong Soon;Park, Soo Nam
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.44 no.4
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    • pp.363-373
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    • 2018
  • In recent years, parabens used as preservatives in cosmetics have become a problem of human safety. Therefore, in this study, we tried to evaluate the preservative efficacy of 1,3-butylene glycol, 1,2-hexanediol, and 1,2-pentanediol as a preservative system to replace parabens. 1,3-Butylene glycol was added to cosmetic creams at a concentration of between 5 and 25%. The preservative efficacy of 1,3-butylene glycol was determined using a M-3 challenge test, as recommended by the Personal Care Products Council (formally CTFA). The alkane diols, such as 1,2-hexanediol and 1,2-pentanediol, were assessed in a similar manner. An evaluation of the preservative efficacy of 1,3-butylene glycol revealed that it was effective against all tested microbial strains at a concentration of 25%. We also investigated the efficacy of combinations of 0.3% phenoxyethanol and 0.1% ethylhexylglycerin. Finally, we tested the alkane diols, including 1,2-hexanediol and 1,2-pentanediol, as an alternative to the preservative 0.3% phenoxyethanol. Both 1% 1,2-hexanediol and 1% 1,2-pentanediol demonstrated preservative efficacy. Taken together, our study demonstrated that the formulation of 25% 1,3-butylene glycol and 0.1% ethylhexylglycerin, 1% 1,2-hexanediol, and 1% 1,2-pentanediol had the best preservative efficacy of the compositions tested. Thus, this study suggests that the formulation is a possibility of substituting parabens preservatives, which has been used in cosmetics and has become a safety issue.

Antimicrobial effect of toothbrush with light emitting diode on dental biofilm attached to zirconia surface: an in vitro study (지르코니아 표면에 부착된 바이오필름에 대한 LED 치솔의 항균효과)

  • Park, Jong Hew;Kim, Yong-Gun;Um, Heung-Sik;Lee, Si Young;Lee, Jae-Kwan;Chang, Beom-Seok
    • Journal of Dental Rehabilitation and Applied Science
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    • v.35 no.3
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    • pp.160-169
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    • 2019
  • Purpose: The purpose of this study was to evaluate the antimicrobial effects of a toothbrush with light-emitting diodes (LEDs) on periodontitis-associated dental biofilm attached to a zirconia surface by static and dynamic methods. Materials and Methods: Zirconia disks (12 mm diameter, 2.5 mm thickness) were inserted into a 24-well plate (static method) or inside a Center for Disease Control and Prevention (CDC) biofilm reactor (dynamic method) to form dental biofilms using Streptococcus gordonii and Fusobacterium nucleatum. The disks with biofilm were subdivided into five treatment groups-control, commercial photodynamic therapy (PDT), toothbrush alone (B), brush with LED (BL), and brush with LED+erythrosine (BLE). After treatment, the disks were agitated to detach the bacteria, and the resulting solutions were spread directly on selective agar. The number of viable bacteria and percentage of bacterial reduction were determined from colony counts. Scanning electron microscopy (SEM) was performed to visualize alterations in bacterial morphology. Results: No significant difference in biofilm formation was observed between dynamic and static methods. A significant difference was observed in the number of viable bacteria between the control and all experimental groups (P < 0.05). The percentage of bacterial reduction in the BLE group was significantly higher than in the other treated groups (P < 0.05). SEM revealed damaged bacterial cell walls in the PDT, BL, and BLE groups, but intact cell walls in the control and B groups. Conclusion: The findings suggest that an LED toothbrush with erythrosine is more effective than other treatments in reducing the viability of periodontitis-associated bacteria attached to zirconia in vitro.

Isolation and characterization of cellulolytic yeast belonging to Moesziomyces sp. from the gut of Grasshopper (메뚜기의 내장에서 분리한 Moesziomyces 속에 속하는 셀룰로오스 분해 효모의 분리 및 특성)

  • Kim, Ju-Young;Jung, Hee-Young;Park, Jong-Seok;Cho, Sung-Jin;Lee, Hoon Bok;Sung, Gi-Ho;Subramani, Gayathri;Kim, Myung Kyum
    • Korean Journal of Microbiology
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    • v.55 no.3
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    • pp.234-241
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    • 2019
  • An intensive interaction between yeasts and insects has highlighted their relevance for attraction to food and for the insect's development and behavior. Yeast associated in the gut of insects secretes cellulase which aided in the food digestion (cellulose degradation). Three strains of cellulose-degrading yeast were isolated from the gut of adult grasshoppers collected in Gyeonggi Province, South Korea. The strains $ON22^T$, $G10^T$, and $G15^T$, showed positive cellulolytic activity in the carboxymethyl cellulose (CMC)-plate assay. The phylogenetic tree based on sequence analysis of D1/D2 domains of the large subunit rRNA gene and the internal transcribed spacer (ITS) regions revealed that the strains $ON22^T$ (100 and 98.4% sequence similarities in D1/D2 domains and ITS) and $G10^T$ (99.8 and 99.5% in D1/D2 domain and ITS region) were most closely related to the species Moesziomyces aphidis JCM $10318^T$; $G15^T$ (100% in D1/D2 domains and ITS) belongs to the species Moesziomyces antarcticus JCM $10317^T$, respectively. Morphology and biochemical test results are provided in the species description. Cellulase with its massive applicability has been used in various industrial processes such as biofuels like bioethanol productions. Therefore, this is the first report of the cellulolytic yeast strains $ON22^T$, $G10^T$, and $G15^T$ related to the genus Moesziomyces in the family Ustilaginaceae (Ustilaginales), in Korea.

Comparison of gut microbial diversity of breast-fed and formula-fed infants (모유수유와 분유수유에 따른 영아 장내 미생물 군집의 특징)

  • Kim, Kyeong Soon;Shin, Jung;Sim, JiSoo;Yeon, SuJi;Lee, Pyeong An;Chung, Moon Gyu
    • Korean Journal of Microbiology
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    • v.55 no.3
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    • pp.268-273
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    • 2019
  • The intestinal microbiomes vary according to the factors such environment, age and diet. The purpose of this study was to compare the gut microbial diversity between Korean infants receiving breast-fed milk and formula-fed milk. We analyzed microbial communities in stool samples collected from 80 Korean infants using next generation sequencing. Phylum level analysis revealed that microbial communities in both breast-fed infants group (BIG) was dominated by Actinobacteria ($74.22{\pm}3.48%$). Interestingly, the phylum Actinobacteria was dominant in formula-fed infants group A (FIG-A) at $73.46{\pm}4.12%$, but the proportions of phylum Actinobacteria were lower in formulafed infants group B and C (FIG-B and FIG-C) at $66.52{\pm}5.80%$ and $68.88{\pm}4.33%$. The most abundant genus in the BIG, FIG-A, FIG-B, and FIG-C was Bifidobacterium, comprising $73.09{\pm}2.31%$, $72.25{\pm}4.93%$, $63.81{\pm}6.05%$, and $67.42{\pm}5.36%$ of the total bacteria. Furthermore, the dominant bifidobacterial species detected in BIG and FIG-A was Bifidobacterium longum at $68.77{\pm}6.07%$ and $66.85{\pm}4.99%$ of the total bacteria. In contrast, the proportions of B. longum of FIG-B and FIG-C were $58.94{\pm}6.20%$ and $61.86{\pm}5.31%$ of the total bacteria. FIG-A showed a community similar to BIG, which may be due to the inclusion of galactooligosaccharide, galactosyllactose, synergy-oligosaccharide, bifidooligo and improvement material of gut microbiota contained in formula-milk. We conclude that 5-Bifidus factor contained in milk powder promotes the growth of Bifidobacterium genus in the intestines.

Complete genome sequence of Lachnospiraceae bacterium KGMB03038 (=KCTC 15821) isolated from healthy Korean feces (건강한 한국인 분변으로부터 분리된 Lachnospiraceae bacterium KGMB03038 (=KCTC 15821) 균주의 유전체 염기서열 초안)

  • Kim, Ji-Sun;Kang, Se Won;Han, Kook-Il;Lee, Keun Chul;Eom, Mi Kyung;Suh, Min Kuk;Kim, Han Sol;Lee, Ju Huck;Park, Seung-Hwan;Park, Jam-Eon;Oh, Byeong Seob;Yu, Seung Yeob;Choi, Seung-Hyeon;Ryu, Seoung Woo;Lee, Dong Ho;Yoon, Hyuk;Kim, Byung-Yong;Lee, Je Hee;Lee, Jung-Sook
    • Korean Journal of Microbiology
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    • v.55 no.3
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    • pp.289-292
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    • 2019
  • Lachnospiraceae bacterium KGMB03038 (=KCTC 15821) belonging to the class Clostridia in phylum Firmicutes, was isolated from a stool sample of a healthy Korean. Herein, we report the complete genome sequence of strain KGMB03038 analyzed using the PacBio Sequel platform. The genome comprises of 3,334,474 bp with G + C content of 47.8%, which includes 3,099 predicted protein-coding genes, 12 ribosomal RNAs, 54 transfer RNAs, and 4 ncRNAs. Genome analysis revealed that strain KGMB03038 possesses a number of genes involved in hydrolysis of carbohydrates, including mono-, di-, and oligo-saccharides, and biosynthesis of various amino acids.