• Title/Summary/Keyword: microbial composition

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Preservation of Washed Fresh Ginsengs by Gamma Irradiation (방사선(放射線) 조사(照射)에 의한 수세된 수삼(水蔘)의 저장(貯藏))

  • Cho, Han-Ok;Byun, Myung-Woo;Kwon, Joong-Ho;Lee, Jae-Won
    • Applied Biological Chemistry
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    • v.29 no.3
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    • pp.288-293
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    • 1986
  • The washed fresh ginsengs packed with air, vaccum and nitrogen gas were irradiated at the levels of 1,2 and 3kGy gamma radiation and then stored at $4{\sim}5^{\circ}C$ for 90days to investigate the effects of gamma radiation on microbial inactivation, eelworm disinfestation and physicochemical changes. After a 90 day storage, $2{\sim}3kGy$ irradiated groups showed 20% of weight loss and 10% of rot while non-irradiated group 100% and 20% or more, respectively. Also the irradiated groups showed somewhat lower values of specific gravity, color density and hardness immediately after irradiation, thereafter higher value of them with storage time than those of non-irradiated group. The irradiation increased the yields of ginseng extract and crude saponins but no effects on the proximate composition and TLC and HPLC patterns of saponin. The food-borne microorganisms decreased in viable cell counts by $2{\sim}3$ log cycles with $2{\sim}3kGy$ radiation and the eelworms were completely disinfested with 1 kGy radiation.

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The Comparison and Index Components in Quality of Salt-Fermented Anchovy Sauces (멸치 액젓의 품질 비교 및 품질 지표성분에 관한 연구)

  • Oh, Kwang-Soo
    • Korean Journal of Food Science and Technology
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    • v.27 no.4
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    • pp.487-494
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    • 1995
  • To assay the quality of anchovy sauce, 10 kinds of commercial anchovy sauce(CAS) were purchased from markets and traditional anchovy sauce(TAS) were prepared. And their physicochemical-microbial characteristics were compared. The compositions of CAS were as followed; pH $5.5{\sim}5.7$, salinity $21.0{\sim}23.2%$, VBN $92.8{\sim}305.4\;mg/100g$, total nitrogen $928.0{\sim}1870.9\;mg%$, amino-nitrogen $338.6{\sim}680.3\;mg%$, and acidity $11.58{\sim}24.58\;ml$. The CAS was lower in pH, smaller in contents of VBN, total-N, amino-N and larger in contents of moisture, salinity than TAS. In Hunter values, CAS was generally lower in L, b values whereas higher in a and ${\Delta}E$ values than TAS. Viable cell counts on 0% NaCl-medium of CAS and TAS were $6.4{\times}10^1{\sim}3.0{\times}10^5\;and\;8.7{\times}10^4$, and those on 2.5% NaCl-medium were $0.8{\times}10^2{\sim}2.2{\times}10^5\;and\;1.6{\times}10^4{\sim}4.5{\times}10^5$, respectively. These viable cell counts in CAS and TAS were gradually decreased according to storage time. In composition of extractives, total free amino acid contents of CAS and TAS were $5498.5{\sim}12123.8\;mg%$, 12797.9 mg%, and these contents were gradually decreased during storage. The major amino acids were found glutamic acid, alanine and leucine in CAS, and alanine, glutamic acid, leucine and valine in TAS. Also contents of hypoxanthine, TMAO, TMA in CAS and TAS were shown $86.4{\sim}161.2\;mg%,\;51.6{\sim}99.2\;mg%,\;23.2{\sim}42.9\;mg%$ and 103.7 mg%, 128.8 mg%, 55.8 mg%, respectively. We may conclude from the results of present experiments that parts of tested CAS were somewhat putrefied and there was a great difference in the quality compared with TAS, whereas TAS maintained good conditions for preserving the quality until storage 2 years.

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Changes of Major Components and Microorganisms during the Fermentation of Korean Ordinary Kochujang (한국재래식(韓國在來式)고추장숙성중(熟成中)의 주요성분(主要成分) 및 미생물(微生物)의 변화(變化))

  • Ahn, Cheol-Woo;Sung, Nack-Kie
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.16 no.3
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    • pp.35-39
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    • 1987
  • The present study was attempted to obtain the basic data concerning a reasonable preparing method and the optimum fermentation conditions of Kochujang (Red pepper paste). To establish the standard qualify of Kochujang, changes of the chemical composition and the numbers of bacteria and feasts in Kochujang during fermentation were observed. Moisture, salts and crude ash contents of Kochujang were not changed significantly during fermentation. Titrable acidity and amino nitrogen gradually increased with the time-passed, whereas crude fat gradually decreased with the time-elapsed. And reducing sugar and total nitrogen increased until 40 days, but slightly decreased after this period. The numbers of bacteria and yeasts in the ingrients for the preparation of Kochujang were $3.9{\times}10^7/g$, $1.5{\times}10^3/g$ in red pepper powder, $7.6{\times}10^4/g$, $2.8{\times}10^2/g$ in salts. respectively, but those of sugar and malt were not more than 100/g. Microbial counts in Kochujang during fermentation increased until 40 days, but those are gradually decreased after that.

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Quality Evaluation of Minimally Processed Asian Pears (신선편의 식품화된 신고배의 저장 중 이화학적 품질변화)

  • Kim, Gun-Hee;Cho, Sun-Duk;Kim, Dong-Man
    • Korean Journal of Food Science and Technology
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    • v.31 no.6
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    • pp.1523-1528
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    • 1999
  • The consumer's demands for minimally processed fruits and vegetables have been increased rapidly because of its convenient handling, fresh-like quality as well as producing less wastes from the environmental point of view. Asian pears which are one of the main fruits widely produced and consumed in Korea easily lost their characteristics due to browning and softening after cutting. The objective of this study is to investigate the effects of various treatments on delaying deterioration of sliced Asian pears. 'Shingo' pear slices were treated with various solutions $(1%\;NaCl,\;0.2%\;L-cysteine,\;1%\;CaCl_2\;or\;1%\;calcium\;lactate)$ and were packaged with low density polyethylene $(LDPE,\;60\;{\mu}m)$, ceramic $(CE,\;60\;{\mu}m)$ or vacuum $(Ny/PE,\;80\;{\mu}m)$ film at $20^{\circ}C\;and\;0^{\circ}C$. In order to evaluate the quality of packaged sliced pears, quality index was determined in terms of color, firmness, soluble solids, titratable acidity. ascorbic acid, changes of gas composition, microbial test, and sensory quality. The results showed that sliced 'Shingo' pears packaged with CE and vacuum film maintained better quality than with LDPE at $0^{\circ}C\;and\;20^{\circ}C$. To retard browning and softening. 0.2% L-cysteine and 1% NaCl solutions applied for 1 minute were effective to reduce surface browning of sliced pears, and 1% $CaCl_2$ was the most effective to prevent softening.

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Chemical and Functional Characteristics of Mechanically Deboned Chicken meat and its Utilization in Processed Meat (기계발골가금육의 특성 및 이용에 관한 연구)

  • 김종원;안병윤;이유방
    • Korean Journal of Poultry Science
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    • v.7 no.2
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    • pp.37-46
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    • 1980
  • Hand deboned and mechanically deboned chicken meat were produced from domestic broilers and spent layers. Meat yield, chemical composition, functional characteristics, stability during storage, and microbiological properties were investigated Chicken patties and frankfurters were also manufactured by varying the relative proportion of MDCM to HDCM as raw materials, ana their palatability, shelf-life and textural properties were evaluated. The obtained results were as follows: 1) 35% of carcass wt was recovered as HDCM and 45% as MDCM, total meat yield reaching 80% of carcass wt. 2) Moisture, protein, fat, ash and Ca content of MDCM were 65, 12, 20, 1.7 and 0.2-0.4%,respectively. MDCM was higher in fat, ash and Ca, but significantly lower in moisture and protein. Total pigment content of MDCM was 2.5 times higher than that of HDCD such high content being attributed to the increased inclusion of hemoglobin. 3) The emulsifying capacity (ES) of MOCM per g meat was only 70% that of HDCM. but when ES was expressed on unit g of protein basis MDCM showed even higher ES than HDCM primarily due to tile higher proportion of salt soluble protein fraction. 4) Since the TBA values of MDCM increased rapidly after 4 weeks of frozen storage at -20$^{\circ}C$, the maximum possible storage period of MDCM is estimated to be about 4 weeks. 5) Total microbial counts of MDCM was approximately 1.8${\times}$10$\^$6/g/, showing no great difference from HDCM or red meat. 6) Chicken patty containing MDCM showed gradual increase in TBA value during frozen storage, but its storage up to 8 weeks presented no problems in flavor stability. 7) Color score an4 total palatability of chicken Patty were best for the product containing 30% MDCM. It was also concluded that MDCM can be included in the patties up to 50% of total meat with good results, but more than 70% was not recommended 8) The formulation of MDCM up to 50% in frankfurter gave quite satisfactory acceptability and textural properties comparable to frankfurter made of 100% MDCM, but the inclusion of more than 70% MDCM was not recommended 9) The TBA value of frankfurter containing MDCM did not increase to any great extent until 4 weeks of storage at 4$^{\circ}C$, indicating no unique problems in flavor instability compared to regular frankfurter. 10) It was concluded that processed meat products such as patties and frankfurters containing MDCM up to 30-50% of total meat ingredients gave satisfactory results in color, texture and palatability, comparable to regular products.

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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.

The synthesis of dextran from rice hydrolysates using Gluconobacter oxydans KACC 19357 bioconversion (Gluconobacter oxydans 생물전환을 통한 쌀 가수분해물 유래 dextran 합성)

  • Seung-Min Baek;Hyun Ji Lee;Legesse Shiferaw Chewaka;Chan Soon Park;Bo-Ram Park
    • Food Science and Preservation
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    • v.31 no.1
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    • pp.149-160
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    • 2024
  • Dextran is a glucose homo-polysaccharide with a predominantly α-1,6 glycosidic linkage of microbial source and is known to be produced primarily by lactic acid bacteria. However, it can also be obtained through the dextran dextrinase of acetic acid bacteria (Gluconobacter oxydans). The dextrin-based dextran was obtained from rice starch using G. oxydans fermentation of rice hydrolysate, and its properties were studied. Both dextrin- and rice hydrolysate-added media maintained the OD value of 6 after 20 h of incubation with acetic acid bacteria, and the gel permeation chromatography (GPC) analysis of the supernatant after 72 h of incubation confirmed that a polymeric material with DP of 480 and 405, which was different from the composition of the substrate in the medium, was produced. The glucose linkage pattern of the polysaccharide was confirmed using the proton nuclear magnetic resonance (1H-NMR) and the increased α-1,4:α-1,6 bond ratio from 0.23 and 0.13 to 1:2.37 and 1:4.4, respectively, indicating that the main bonds were converted to α-1,6 bonds. The treatment of dextrin with a rat-derived alpha-glucosidase digestive enzyme resulted in a slow release of glucose, suggesting that rice hydrolysate can be converted to dextran using acetic acid bacteria with glycosyltransferase activity to produce high-value bio-materials with slowly digestible properties.