• Title/Summary/Keyword: bacterial food

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Optimization of Culture Condition of Gluconacetobacter hansenii TF-2 for Cellulose Gel Production (Gluconacetobacter hansenii TF-2를 이용한 감귤과즙으로부터의 셀루로스 겔 생산의 최적화)

  • 최경호;정지숙;문철호;김미림
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.1
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    • pp.176-181
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    • 2004
  • Gluconacetobacter hansenii TF-2, an isolate from black tea fungus, was statically cultivated to ferment cellulose gel from citrus juice. The juice prepared by press filtering of peeled citrus fruit contained 135.5 mg of total sugar/mL, 1.23% of total acid, and average pH of the juice was 3.98. The bacterium produced cellulose gel optimally on the surface of culture broth containing 17% of citrus juice and 10$^{\circ}$Brix of total sugar. The optimum temperature was 3$0^{\circ}C$ for producing acetic acid and gel formation. The bacterium could not produce acetic acid on gel formation at 4$0^{\circ}C$. The optimum pH was 3.0∼4.0 but was not significantly different between pH 3.0∼4.0. The cultivation for 18 days under optimal conditions produced gel as 14.2$\pm$0.6 mm of thickness and acids equivalent to 1.90$\pm$0.22% of acetic acid. The pH of culture broth was stabilized at 2.6∼2.8 during the cultivation. Remaining sugar content was 27.1$\pm$4.2 mg/mL of total sugar and 6.9 mg/mL of reducing sugar. The gel productivity was 137.8$\pm$9.7 g/L.

Effect of Carbon Source Supplement on the Gel Production from Citrus Juice by Gluconacetobacter hansenii TL-2C (Gluconacetobacter hansnii TL-2C에 의한 감귤과즙 발효시 겔 생성에 미치는 탄소원의 영향)

  • 최경호;정지숙;문철호;김미림
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.33 no.1
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    • pp.170-175
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    • 2004
  • This study was conducted to determine the minimum concentration of citrus juice for basal medium and also to search for an additional carbon source for the best production of the gel. A concentrate of citrus fruit juice of 65$^{\circ}$Brix, it was diluted to be used as a basal medium. Static cultivation of Gluconacetobacter hansenii TL-2C for 14 days at 3$0^{\circ}C$ produced the best gel with 7.5$\pm$0.4 mm thickness in the 6-fold diluted citrus Juice concentrate without any additional nutrient. However, the same thickness could be obtained with 60 to 100-fold diluted juice concentrate when refined white sugar was added at appropriate concentrations. Glucose was the most effective sugar for the both of gel and acid production, and optimal concentration of the sugar was 10$^{\circ}$Brix. Ethyl alcohol at 1.0% had synergistic effects in combination with refined sugar and increased the gel thickness up to 15.1 mm which was 1.85 times thicker than that of refined sugar alone. However, acetic acid was not effective. Gel productivity with supplement of ethanol was 172.6$\pm$8.4 g wet/L, and it was approximately equal to 4.7 g of dry gel/L.

Verification of Antibacterial Activities of Oriental Herbal Medicine Extracts (한약재 추출물의 항균활성 검증)

  • Lee, Chang-Eun;Jo, Jung-Kwon;Kim, Jae-Deok;Lee, Dong-Geun;Kim, Won-Seok;Lee, Sang-Hyeon
    • Journal of Life Science
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    • v.27 no.6
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    • pp.611-616
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    • 2017
  • The antibacterial activities of nine oriental herbal medicine extracts were measured against seven kinds of bacteria known to cause food poisoning and disease. The extracts were prepared with distilled water using an autoclave ($121^{\circ}C$ for 30 min). The extraction yields of nine oriental herbal medicines were in the rage of 0.5%-33.4%. The antibacterial activities were evaluated using the paper-disc method. Extracts of Hwangryeon, Jiyu, and Ohbaeja showed antibacterial activities while the others did not. Extracts of Coptis japonica, Hwangryeon, and Sanguisorba officinalis, Jiyu showed antibacterial activities only against Clostridium perfringens and Listeria monocytogenes. Extracts of Rhus javanica, Ohbaeja showed the strongest antibacterial activities against all the bacteria tested. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of R. javanica extracts were in the range of 2.4~20 mg/ml for the bacteria tested. In conclusion, the extract of R. javanica showed superior antibacterial activities against the seven bacterial strains tested. The MIC and MBC values for each bacterium were represented as strain names (MIC, MBC), which were Bacillus cereus (11.2, 20), Clostridium perfringens (2.4, 4.7), Escherichia coli (9.1, 9.1), Listeria monocytogenes (11.1, 20), Salmonella typhi (4.7, 9.1), Staphylococcus aureus (2.4, 4.7), and Vibrio parahaemolyticus (2.4, 5.3). Further purification and study of this antibacterial material would be helpful for developing antibiotics or promoting synergistic effects with known antibiotics, producing antibacterial material for lengthening the shelf-life of food, and so on.

Effects of Addition of Mugwort Powder on the Physicochemical and Sensory Characteristics of Boiled Pork (쑥 분말 첨가가 돼지고기 수육의 이화학적 및 관능적 특성에 미치는 영향)

  • 정인철;문윤희;강세주
    • Food Science of Animal Resources
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    • v.24 no.1
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    • pp.15-22
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    • 2004
  • The effects of carcass grade and addition of mugwort powder on the quality of the boiled pork were investigated. Four kinds of boiled pork were denoted as B$\_$+/ or E$\_$+/ boiled porks which were made with 0.3% mugwort powder to carcass grade B or E, respectively, and B$\_$0/ or E$\_$0/ boiled porks which were made without mugwort powder. The effect of carcass grade and the added mugwort powder on the pH, volatile basic nitrogen(VBN), bacterial count, calorie, essential amino acids, free amino acids, unsaturated fatty acids, color difference and palatability of boiled porks were not significant. Water holding capacity(WHC), springiness and Hunter's L$\^$*/ value of B$\_$0/ boiled pork were higher than those of E$\_$0/ boiled pork. Hunter's a$\^$*/ value of B$\_$0/ boiled pork were lower than those of E$\_$0/ boiled pork. Sensory taste and tenderness value of B$\_$0/ boiled pork were higher than those of E$\_$0/ boiled pork(p>0.05). WHC, 2-thiobarbituric acid reactive substances(TBARS) value and residual nitrite of boiled pork with mugwort powder were lower than those of boiled pork without mugwort powder.

Influence of Supplementing Dairy Cows Grazing on Pasture with Feeds Rich in Linoleic Acid on Milk Fat Conjugated Linoleic Acid (CLA) Content

  • Khanal, R.C.;Dhiman, T.R.;Boman, R.L.;McMahon, D.J.
    • Asian-Australasian Journal of Animal Sciences
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    • v.20 no.9
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    • pp.1374-1388
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    • 2007
  • Three experiments were conducted to investigate the hypothesis that cows grazing on pasture produce the highest proportion of c-9 t-11 CLA in milk fat and no further increase can be achieved through supplementation of diets rich in linoleic acid, such as full-fat extruded soybeans or soybean oil. In experiment 1, 18 lactating Holstein cows were used in a randomized complete block design with measurements made from wk 4 to 6 of the experiment. In experiment 2, three cannulated lactating Holstein cows were used in a $3{\times}3$ Latin square design. Each period was 4 wk with measurements made in the final wk of each period. Cows in both experiments were assigned at random to treatments: a, conventional total mixed ration (TMR); b, pasture (PS); or c, PS supplemented with 2.5 kg/cow per day of full-fat extruded soybeans (PES). In both experiments, feed intake, milk yield, milk composition, and fatty acid profile of milk and blood serum were measured, along with fatty acid composition of bacteria harvested from rumen digesta in experiment 2. In experiment 3, 10 cows which had continuously grazed a pasture for six weeks were assigned to two groups, with one group (n = 5) on pasture diet alone (PS) and the other group (n = 5) supplemented with 452 g of soy oil/cow per day for 7 d (OIL). In experiment 1, cows in PS treatment produced 350% more c-9, t-11 CLA compared with cows in TMR treatment (1.70 vs. 0.5% of fat), with no further increase for cows in PES treatment (1.50% of fat). Serum c-9, t-11 CLA increased by 233% in PS treatment compared with TMR treatment (0.21 vs. 0.09% of fat) with no further increase for cows in PES treatment (0.18% of fat). In experiment 2, cows in PS treatment produced 300% more c-9 t-11 CLA in their milk fat compared with cows in TMR treatment (1.77 vs. 0.59% of fat), but no further increase for cows in PES treatment (1.84% of fat) was observed. Serum c-9, t-11 CLA increased by 250% for cows in PS treatment compared with cows in TMR treatment (0.27 vs. 0.11% of fat), with no further increase for cows in PES treatment (0.31% of fat). The c-9, t-11 CLA content of ruminal bacteria for cows in PS treatment was 200% or more of TMR treatment, but no further increase in bacterial c-9, t-11 CLA for cows in PES treatment was observed. Supplementation of soy oil in experiment 3 also did not increase the c-9 t-11 CLA content of milk fat compared with cows fed a full pasture diet (1.60 vs. 1.54% of fat). Based on these findings, it was concluded that supplementing with feeds rich in linoleic acid, such as full-fat extruded soybeans or an equivalent amount of soy oil, to cows grazing perennial ryegrass pasture may not increase milk fat c-9 t-11 CLA contents.

Preparation and Characteristics of Kimchi Tablet (김치 타블렛의 제조와 품질특성)

  • 박석란;최유원;윤광섭;김순동
    • Food Science and Preservation
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    • v.8 no.3
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    • pp.302-307
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    • 2001
  • In order to prepare kimchi tablet(K7), the kimchi was fermented with crushed materials and lactic acid bacterial starter. The effect of raying methods (hot air-drying : HAD, freeze drying: FD), moulding pressure (100, 150 and 200 kg/cm2) and moulding time (0, 1, 2, 3 and 4 min) of kimchi tablet on residual solid, characteristics of filtrate, color, textual properties, hygroscopicity and sensory quality were investigated. No great difference showed in residual solid of the tablet prepared with freeze dried kimchi (FD-KT), but the tablet prepared with hot air-dried kimchi (HAD-KT) decreased markedly with an increase in moulding pressure. Residual solid of FD-KT was lower than that of HAD-KT. The pH and redness for HAD-KT and FD-KT were similar. Total sugar. acidity and lightness of FD-KT as compared with HAD-KT were higher, while higher max, yield, strength and hardness were found for HAD-KT. Color, tactile, flavor, chewing taste, acceptability and hygroscopicity of FD-KT were generally higher than those of HAD-KT. Hygroscopicity of HAD-KT decreased with an increase in moulding pressure in md time, but that of FD-KT increased. Overall qualities of FD-KT and HAD-KT showed best in 200 kg/㎠ of moulding pressure, 3min of moulding time.

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An Identification of Enterobacter sp. Isolated from Contaminated Ginseng and Inhibition Effect of Ginseng Saponin on Its Growth (오염된 인삼으로부터 분리된 Enterobacter sp.의 동정 및 인삼사포닌의 균 생육억제효과)

  • 곽이성;이종태;여운형
    • Journal of Food Hygiene and Safety
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    • v.17 no.1
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    • pp.26-30
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    • 2002
  • A bacterium isolated from contaminated white ginseng was indentified by using API kit and electron microscope. The isolate was determined as rod shaped bacterium having 0.6-1.0 ${\mu}{\textrm}{m}$ in diameter and 1.2-3.0 ${\mu}{\textrm}{m}$ in length. It had motility by flagellum. The isolate had $\beta$-galactosidase, arginine dihydrolase and omithin decarboxylase. It used citrate as sole carbon source but not produced H$_2$S. It also fermented glucose, manitol, sorbitol, rhamnose, sucrose, melibiose, arabinose and amygdalin. The isolate was identified as Enterobacter sp by the above API kit analysis and electron microscopy observation. Ginseng saponin was added to culture of Enterobacter sp. in order to investigate saponin's influence on its growth. The strain was incubated at 38$^{\circ}C$ for 3 days after addition of 0.05, 0.5, 2.0 and 4.0% (w/v) of saponin, respectively and the growth rates were investigated. The relative bacterial growth rates showed 75.0, 37.5, 7.5 and 0.5%, respectively, when compared with 100% of saponin non-added group. These results suggest that the growth of Enterobacter sp. is inhibited by saponin with the concentration dependency.

Changes of Physico-Chemical, Microbilogical and Sensory Properties on Hanwoo Beef Fed With Supplemental Bamboo Vinegar during Refrigerated Storage (죽초액을 급여한 한우육의 냉장 저장기간 중 물리화학적, 미생물학적 및 관능 특성의 변화)

  • Kook Kil;Kim Kwang-Hyun
    • Food Science of Animal Resources
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    • v.25 no.4
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    • pp.403-408
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    • 2005
  • The objective of this study was to investigate the effects of supplemental levels of Bamboo vinegar (BV) on meat quality characteristics of Hanwoo. A total of 15 cows $(400.0\pm15.0\;kg)$ was fed with a commercial diet (control) or $3\%$ bamboo vinegar supplemented diets $(3\%\;BV),\;6\%$ BV for four months. Then, cows were slaughtered and M. longissimus dorsi (LD) was collected from each treatment group During storage at $4^{\circ}C$ for 21day, physico-chemical, microbiological and sensory characteristics were determined It increased (p<0.05) in at 3 and 9 days of the refrigeration storage. Hunter a value decreased (p<0.05) in the meat fed with $3\%\;and\;6\%$ BV at 1, 3 and 9 days. Hunter b value increased (p<0.05) in $3\%\;and\;6\%$ BV at 1 and 3 days. TBA and total bacterial count were significantly (p<0.05) low in $3\%\;and\;6\%$ BV at 1 and 3 days. Supplementation of $3\%\;or\;6\%$ BV showed a significant (p<0.05) decrease in cooking loss at 9 and 15 days. $3\%\;and\;6\%$ BV showed a significant (p<0.05) decrease in shear force at 1, 3 and 9 days; it tended to decrease throughout the whole storage period The treatments $3\%\;and\;6\%$ BV scored high in area of taste; taste increased significantly (p<0.05) at 1 and 3 days.

Quality Characteristics of Low-Fat Sausage Containing Curcumin Extract during Cold Storage (울금 추출물 함유 저지방 소시지의 냉장저장 중 품질 특성)

  • Kim, Il-Suk;Jin, Sang-Keun;Park, Ki-Hoon;Jeong, Ki-Jong;Kim, Dong-Hoon;Yang, Mi-Ra;Chung, Young-Sin
    • Food Science of Animal Resources
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    • v.27 no.3
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    • pp.255-261
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    • 2007
  • The effects of curcumin extract on the physicochemical, microbial and sensory properties of low-fat sausages during refrigerated storage were studied. Sausage products were produced with three different formulations including 0%, 2.5%, and 5.0% curcumin extract. Low-fat sausages made with the addition of curcumin extract had lower (p<0.05) crude fat content, pH and TBARS values than the control sample. The addition of curcumin extract did not affect the water holding capacity, cooking loss, shear force, meat color, texture profile, and total bacterial count in low-fat sausages duringstorage (p>0.05). With regard to sensory evaluation, 2.5% curcumin extract added to low-fat sausages resulted in a high overall acceptability (p<0.05). In conclusion, low-fat sausages with added 2.5% curcumin extract had a higher acceptability and lipid oxidative stability during storage than products without curcumin extract.

Quality Characteristics of Fermented Soybean Products by Bacillus sp. Isolated from Traditional Soybean Paste (전통장류 유래 Bacillus sp.를 이용한 콩 발효물의 품질 특성)

  • Lee, Sun Young;Eom, Jeong Seon;Choi, Hye Sun
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.43 no.5
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    • pp.756-762
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    • 2014
  • This study evaluated the quality characteristics of soybean fermented with several Bacillus sp., which were selected based on their high enzymatic and antimicrobial activities. Total aerobic bacterial counts of fermented soybeans with HJ5-2 ($3.00{\times}10^9CFU/mL$) were the highest among all strains. Lactic acid bacteria numbered $2.50{\times}10^2{\sim}7.30{\times}10^4CFU/mL$ in soybeans fermented with isolates. Amylase and protease activities of the RD7-7 sample were the highest among all strains. Reducing sugar and amino-type nitrogen contents of fermented soybeans with HJ18-4 (2.35%) and RD7-7 (227.96 mg%) were the highest. Total amino acid contents of the samples were 16.62~18.38%, and glutamic acid, aspartic acid, leucine, lysine, arginine were major amino acids. Oxalic acid (36.51~63.57 mg/100 g) and succinic acid (429.49~600.15 mg/100 g) were the predominant organic acid. These results provide useful information for development starter (single and complex) as well as for the production of high quality fermented soybean foods.