• Title/Summary/Keyword: juice pH

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Isolation and Characterization of Exopolysaccharide Producing Lactic Acid Bacteria from Korean Soy Sauce and Soybean Paste (전통 장류로부터 Exopolysaccharide 생성 유산균의 분리 및 특성)

  • Yun, Hye Ju;Lee, You Jung;Yeo, Soo-Hwan;Park, Hye Young;Park, Heui-Dong;Baek, Seong Yeol
    • Microbiology and Biotechnology Letters
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    • v.41 no.2
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    • pp.190-197
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    • 2013
  • Three slime-forming lactic acid bacteria were isolated from traditional Korean fermented soy sauce and soybean paste and shown to produce exopolysaccharides (EPS) in sucrose media. By isolating the strains, examining their morphological characteristics and determining their 16S rDNA sequences, N58-5 and K6-7 were identified as Leuconostoc mesenteroides and N45- 10 as Leuconostoc citreum. The acid and bile tolerances of these three strains were investigated. Amongst the three lactic acid bacteria, Leuc. citreum N45-10 exhibited the highest viability ($10^5-10^6$ CFU/ml) in 0.05 M sodium phosphate buffer (pH 0.3) for 2 h, in artificial gastric juice for 2 h and in 0.3%, 0.5% oxgall for 24h. Leuc. mesenteroides K6-7, N58-5 and Leuc. citreum N45- 10 were grown in sucrose liquid medium and 8.16 g/L, 3.65 g/L, 16.17 g/L of EPS was collected, respectively. The hydrolyzed EPS was analyzed by HPLC in order to determine the sugar composition of EPS. Leuc. mesenteroides K6-7 and N58-5 showed two peaks indicating glucose and fructose, thus they were determined to be hetero-type polysaccharides. Leuc. citreum N45-10 showed only the glucose polymer, indicating it to be a homo-type polysaccharide. In addition, all three lactic acid bacterial hemolysis did not demonstrate a clear zone in blood agar in the area surrounding a lactic acid bacteria colony.

Studies on the Ecology of Occurrence and Identification of Typhula Snow Mold of Graminous Plants -II. Several Factors Affecting Growth of Typhula incarnata- (화본과식물에 발생하는 설부소입균핵병균(雪腐小粒菌核病菌)의 동정 및 발생상태에 관한 연구 -II. Typhula incarnata의 생육에 미치는 몇 가지 요인-)

  • Kim, Jin-Won;Lee, Du-Hyung;Shim, Gyu-Yul
    • The Korean Journal of Mycology
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    • v.20 no.1
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    • pp.37-43
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    • 1992
  • Typhula incarnata grew over a temperature range of -5 to $20^{\circ}C$ with maximum growth at 10 to $15^{\circ}C$. Sclerotial production for T. incarnata was greatest at the higher temperature. Maximum mycelial growth of this pathogen occurred from pH 5.4 to 6.2. When carbon sources were added to a basal salt medium (Czapek's dox agar) at 5 g carbon sources/l, inulin, soluble starch, galactose, glucose, mannose, manitol, sucrose, maltose, cellobirose, trehalose, raffinose, and dextrin supported growth better than other carbon sources did. Of the twenty-three nitrogen sources tested, glycine, serine, ammonium sulfate, asparagine, asparatic acid, and ${\beta}-alanine$ were the most favorable for mycelial growth of T. incarnata. Cystine and cysteine were poor nitrogen sources. Ammonium salt of nitrogen sources supported growth better than nitrate salt of nitrogen sources. Potato dextrose agar, oat meal agar, and V-8 juice agar were the most favorable for mycelial growth and sclerotial formation. Appropriate addition of pepton to PDA decreased mycelial dry weight, but sucrose supported good growth of T. incarnata. Percent viable sclerotia of T. incarnate buried in bentgrass soil decreased from 2 months after treatment remarkably. Trichoderma riride and bacteria were isolated from non-germinated sclerotia. Live orchard grass leaf pieces within the soil were colonized by T. incarnata better than sterile and unsterile dead leaf pieces at $0^{\circ}C$. Saprophytic ability of T. incarnate on sterile leaf sheath occurred better at $0^{\circ}C$ than at $10^{\circ}C$. Saprophytic microflora consisting of Cladosporium sp., Fusarium sp., Mucor sp., Pythium sp., and unidentified fungi were the competitors for the sterilized and unsterilized substrate, but their colonization was not find on live leaf sheath buried in the soil at $0^{\circ}C$. In the effect of fungicides to Typhula snow mold disease of creeping bentgrass, mixture of polyoxin and thiram was the most effective, followed by iprodione, mixture of iprodione and oxine copper, thiophanate-methyl, myclobutanil, and tolclofos-methyl.

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Effect of Sulfur Dioxide on Crops - Physiology of Lesion, Yield Loss, and Preventive Measures (아황산(亞黃酸)가스에 의(依)한 농작물(農作物)의 피해생리(被害生理) 감수율(減收率) 및 피해경감(被害輕減)에 관(關)한 연구(硏究))

  • Han, Ki-Hak
    • Applied Biological Chemistry
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    • v.16 no.3
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    • pp.146-165
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    • 1973
  • Crop damages caused by sulfur dioxide poisoning were studied with respect to physiology of lesion, yield loss and prevention measures. The results are summarized as follows; 1. On the physiology of injury: The sulfur dioxide gas did no: affect the pH and $E_h$ values of the tested leaf juice of plants. Peroxidase activity was inhibited just after sulfur dioxide treatment but gradually recovered to normal after 10 hours. Methanolic chlorophyll solution was instantaneously and irreversibly bleached by the addition of sulfur dioxide gas with no evidence of pheophytin formation. It seems that chlorophyll forms colourless addition product or is reduced to colourless form with either sulfur dioxide gas or sulfurous acid. Chlorophyll in the chloroplast was also bleached by the sulfur dioxide treatment, as in the case of methanolic solution of chlorophyll, except that the rate of bleaching was rather slow, requiring 1-2 hours. It appears that the most inflicting cause of sulfur dioxide gas to plants may be the destruction of chlorophyll by the poisoning gas. 2. On the effects to crop yield: The crop yield losses were proportional to the concentration of inflicting sulfur dioxide gas. The order of tolerence of the crops to the sulfur dioxide gas was as follows - chinese cabbage being the most susceptible; wheat, paddy rice, barley, soybean, welsh onion, radish and chinese cabbage. The crucifer crops were generally found more susceptible than other crops studied. With respect to the growing stages of crops exposed to sulfur dioxide gas, it was found that the flowering stage was the most susceptible fellowed by panicle forming, milky and tillering in the decreasing order of susceptibility. 3. On the preventive measures of yield losses: Soil applications of potassium, wollastonite, lime or spray of lime water were effective to prevent yield losses from sulfur dioxide fumigation of paddy rice, barley, and soybeans. The most responsive treatment was lime water spray for all crops tested. In case of sulfur dioxide fumigated paddy rice, the lime water spray also increased carbon assimilation.

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Analysis of Chemical Components of Korean Loquat (Eriobotrya japonica Lindl.) Fruit (국내산 비파 열매의 화학적 성분 분석)

  • Lee, Boo-Yong;Park, Eun-Mi;Kim, Eun-Jeong;Choi, Hee-Don;Kim, In-Hwan;Hwang, Jin-Bong
    • Korean Journal of Food Science and Technology
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    • v.28 no.3
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    • pp.428-432
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    • 1996
  • The chemical components of Korean loquat (Eriobotrya japonica Lindl.) fruit were analysed. Approximate compositions of loquat flesh and seed were as follows. respectively crude lipid 0.53% and 0.83%, crude protein 0.05% and 5.27%, crude fiber 3.46% and 3.49%, crude ash 3.24% and 2.78%, carbohydrate 92.72% and 87.63% Soluble solids content, pH and acidity (citric acid) of loquat flesh juice were $12^{\circ}Bx$ by saccharometer, 4.43 and 0.18%, respectively. Free sugar compositions of loquat flesh and seed extracts $(3^{\circ}Bx)$ were as follows, respectively; fructose 0.77% and 0.31%, glucose 0.73% and 0.79%, sucrose 0.52% and 0.19%, ribose and 0.56%, Loquat flesh contained Glu 336.72 mg%, Asp 251.06 mg%, Arg 30.90 mg% and Lys 5.26 mg% Loquat seed contained Glu 448.23 mg%, Asp 335.63 mg%, lle 44.20 mg% and His 37.89 mg%, Potassium (k) contents of loquat flesh and seed were 32627.95 mg% and 28936.28 mg% in total amount of crude ash, while vitamin A and C of loquat flesh and seed were not detected. Composition of major lipid of loquat fruit seed oils fractionated by silicic acid was neutral lipids 43.78%, glycolipids 12.32% and phospholipids 43.90%, Fatty acid compositions of loquat seed lipid extracted by chloroform-methanol (2 : 1) were as follow; palmitic acid 23.72%, stearic acid 3.815, oleic acid 8.55%, linoleic acid 54.29% and linolenic acid 9.63%, Neutral lipids consist of palmitic acid 28.89, stearic acid 6.80%, oleic acid 11.07%, linoleic acid 40.67% and linolenic acid 12.58%, Glycolopids cinsist of palmitic acid 13.21%, stearic acid 4.56%, oleic acid 6.53%, linoleic acid 64.92% and linolenic aicd 10.77% Phospholipids consist of palmitic acid 30.95%, stearic acid 3.40%, oleic acid 9.09%, linoleic acid 48.45% and linolenic acid 8.10%.

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Processing and Property of Olive Flounder Paralichthys olivaceus Terrine (넙치(Paralichthys olivaceus) Terrine 제품의 제조 및 품질특성)

  • YOON, Moon-Joo;LEE, Jae-Dong;PARK, Si-Young;KWON, Soon-Jae;PARK, Jin-Hyo;KANG, Kyung-Hun;CHOI, Jong-Duck;JOO, Jong-Chan;KIM, Jeong-Gyun
    • Journal of Fisheries and Marine Sciences Education
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    • v.27 no.4
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    • pp.1084-1091
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    • 2015
  • Aquaculture of olive flounder started in the middle of 1980's and now farming has been taken place in many places along the coastal line in Korea. The taste of olive flounder has a good chewy texture because of high collagen content, low fat content, so it is popular for sliced raw fish. Olive flounder is popular among Koreans but the consumption pattern is uniformly so as to be used as sliced raw fish but not other ways. So, now there needs to develop high valued-processed food using olive flounder. This study was set to investigate the processing of terrine by using olive flounder, in which terrine is French style meat loaf that is well favored around the world. In this study, terrine was prepared by chopping olive flounder meat with 39 g egg white and 10 mL fresh cream (per 50 g fillet) and then seasoned with 5 mL lemon juice, 5 mL brandy, 0.05 g salt and 0.05 g pepper. The 25 g of dough was placed on a vinyl wrap, put with 2 g cheese, and layered an another 25 g dough, and then rolled up and wrapped by aluminium foil. Two different cooking methods were used for terrine processing in this study. Terrine-1 was cooked by vacuum sealed in polyethylene film ($20{\times}30{\times}0.05mm$) after boiling for 5 min and stored at $-20^{\circ}C$ for 7 days. Terrine-2 was prepared by vacuum sealed in polyethylene film ($20{\times}30{\times}0.05mm$) and stored at $-20^{\circ}C$ for 7 days. After 7 days, Terrine-1 was thawed and then heated up in microwave for 2 min (Sample-1), while Terrine-2 was thawed and then boiled in water for 5 min (Sample-2). Viable bacterial count, chemical composition, pH, salinity, hardness, TBA, free amino acid content, and sensory evaluation were measured for both Sample-1 and Sample-2. Especially, the scores of sensory evaluation of Sample-2 is slightly higher than that of Sample-1. On the other hand, there were no significant differences on color, odor, taste, texture, and overall acceptance between Sample-1 and Sample-2.

Yeast Selection and Comparison of Sterilization Method for Making Strawberry Wine and Changes of Physicochemical Characteristics during Its Fermentation (딸기주 발효를 위한 효모 선발과 살균 방법의 비교 및 발효 중 이화학적 특성의 변화)

  • Jeong, Eun-Jeong;Kim, Yong-Suk;Jeong, Do-Youn;Shin, Dong-Hwa
    • Korean Journal of Food Science and Technology
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    • v.38 no.5
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    • pp.642-647
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    • 2006
  • Yeast selection and the sterilization methods of strawberry juice were optimized for making strawberry wine. In addition, changes in the physicochemical characteristics of the wine during its fermentation were estimated. Maehyang and Yukbo cultivars of strawberry were tested for wine making; they contained 9.8 and 9.3% soluble solids and 0.59 and 0.58% titratable acidities, respectively. Among six yeasts tested, the Wg-15 and Sc-51 strains were selected based on the alcohol yield in the strawberry wine. Alcohol and soluble solid contents following heat treatment ($85^{\circ}C$, 10 min) or $K_2S_2O_5$ (200 ppm) treatment for sterilization were 7.10-7.20% and 5.60-5.80%, respectively, and no differences were observed between the Wg-15 and the Sc-51 strains. However, the flavor of wine produced following heat treatment was slightly better than that following $K_2S_2O_5$ treatment. The greatest amounts of alcohol were produced after 2 days of fermentation at $26^{\circ}C$. The alcohol content in wines produced with 12, 14, and 16% sugar content in the initial stages were 5.1, 6.0-6.2, and 7.5-7.7%, and the soluble solid contents were 3.9-4.3, 4.1-4.3, and 5.0-5.3%, respectively; no significant differences were observed between the Wg-15 and the Sc-51 yeast strains. For making strawberry wine, we proposed that the sugar content of Maehyang or Yukbo cultivars be adjusted to 16% soluble solids in the initial stages with heat treated at $85^{\circ}C$ for 10 min and fermentation with the Wg-15 or Sc-51 yeast strains at $26^{\circ}C$ for 8 days.