• 제목/요약/키워드: high acidity

검색결과 909건 처리시간 0.024초

2단계 발효에 의한 사과식초와 시판 사과식초이 품질비교 (The Quality Comparison of Apple Vinegar by Two Stages Fermentation with Commercial Apple Vinegar)

  • 정용진;서지형;이기동;박난영;최태호
    • 한국식품영양과학회지
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    • 제28권2호
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    • pp.353-358
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    • 1999
  • We produced the apple vinegar with only apple fruits, no adding sugar and others through two stages fermentation(alcohol fermentation and acetic acid fermentation). At the first stage, apple wine contained 5% alcohol was produced at the 5th day. And through the second stage, acetic acid fer mentation, apple vinegars of which total acidity is 5.88% were produced. In comparision with com mercial vinegars for physicochemical quality, it was the lowest in total acidity. But contents of oxalic, tartaric, malic, citric, succinic acid in it were higher than other vinegars. Especially the content of malic acid in it was higher 5 times than other vinegars. Malic acid was known that it was abundant in apple fruits. Also the contents of free amino acids were distinctly high such as 21.97mg% in two stages fermented apple vingars. Potassium content in it was higher 4 times than other vinegars. So it was supposed that two stages fermented vinegar had much higher quality than commercial vinegars.

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Effect of Irradiated Red Pepper Powder on Kimchi Quality during Fermentation

  • Lee, Seung-Cheol
    • Preventive Nutrition and Food Science
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    • 제9권3호
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    • pp.218-221
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    • 2004
  • Irradiated red pepper powder (IRPP) was tested for its ability to retard fermentation and to maintain a high quality of Kimchi by the reduction of the initial microbial load. Kimchi containing IRPP at the doses of 0, 5, 10, 15, or 20 kGy was prepared. Quality indices for Kimchi in this study were pH, titratable acidity, reducing sugar content, total microbial count, lactic acid bacterial load, and sensory evaluation. Based on the pH and titratable acidity, the Kimchi with IRPP showed a retarded fermentation until 15 days. The number of the total aerobes and lactic acid bacteria of the Kimchi with IRPP were lower by about 1 log CFU/mL compared to control at day 0, however, the counts increased to 8.5 log CFU/mL after 10 days, which was similar to the control group. Kimchi that was fermented with 5 kGy IRPP was better than control and other treatments in odor and color, whereas the control scored highest in taste. Addition of IRPP showed a limited retardation of Kimchi fermentation without other quality deterioration.

Highly Active Catalyst of Nickel Sulfate Supported on Titania for Ethylene Dimerization

  • 손종락;박원천
    • Bulletin of the Korean Chemical Society
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    • 제22권12호
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    • pp.1303-1308
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    • 2001
  • A series of catalysts, NiSO4/TiO2, for ethylene dimerization was prepared by the impregnation method using aqueous solution of nickel sulfate. On the basis of the results obtained from X-ray diffraction, the addition of NiSO4 shifted the transition of TiO2 from the anatase to the rutile phase toward higher temperatures due to the interaction between NiSO4 and TiO2. Nickel sulfate supported on titania was found to be very active even at room temperature. The high catalytic activity of NiSO4/TiO2 closely correlated with the increase of acidity and acid strength due to the addition of NiSO4. It is suggested that the active sites responsible for ethylene dimerization consist of low valent nickel, Ni+, with an acid.

Characterization of Zirconium Sulfate Supported on Zirconia and Activity for Acid Catalysis

  • 손종락;권태동;김상복
    • Bulletin of the Korean Chemical Society
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    • 제22권12호
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    • pp.1309-1315
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    • 2001
  • Zirconium sulfate supported on zirconia catalysts were prepared by impregnation of powdered $Zr(OH)_4$ with zirconium sulfate aqueous solution followed by calcining in air at high temperature. The characterization of prepared catalysts was performed using Fourier transform infrared (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and by the measurement of surface area. The addition of zirconium sulfate to zirconia increased the phase transition temperature of $ZrO_2$ from amorphous to tetragonal due to the interaction between zirconium sulfate and zirconia, and the specific surface area and acidity of catalysts increased in proportion to the zirconium sulfate content up to 10 wt% of $Zr(SO_4)_2$. Infrared spectra of ammonia adsorbed on $Zr(SO_4)2}ZrO_2$ showed the presence of Bronsted and Lewis acid sites on the surface. $10-Zr(SO_4)_2}ZrO_2$ calcined at $600^{\circ}C$ exhibited maximum catalytic activities for 2-propanol dehydration and cumene dealkylation. The catalytic activities for both reactions were correlated with the acidity of catalysts measured by ammonia chemisorption method.

Acetobacter sp. SK-7에 의한 매실식초 발효 (Acetic Acid Fermentation by Acetobacter sp. SK-7 using Maesil Juice)

  • 김미향;최웅규
    • 한국식생활문화학회지
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    • 제21권4호
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    • pp.420-425
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    • 2006
  • This study was conducted to produce vinegar using maesil. Acetic acid bacteria was 20 strains isolated from several conventional vinegars. Among the isolates, a strain showed highest acetic acid productivity was selected and identified as Acetobacter sp. SK-7. The optimum medium of acetic acid production by Acetobacter sp. SK-7 was 30% of maesil juice, 4% of ethanol, and 2% of starting acidity and 0.2% of glucose. Optomum condition for the high yield of acetic acid was in the shaking culture at 30$^{\cire}$. The acidity of culture medium was reached to 7.1% after 12 days fermentation. Organic acid was identify 6 kinds containing acetic acid. The total content was 7,068.7 mg% after 12 days and malic acid slowly decreased and acetaic and citirc acid gradationally increased according to fermentation

김해지역의 산성강우와 기압유형 (Weather Patterns and Acid Rain at Kimhae Area)

  • 박종길;황용식
    • 한국환경과학회지
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    • 제8권3호
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    • pp.271-280
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    • 1999
  • This study was carried out to investigate the characteristics of acidity in the precipitation and weather patterns that were influenced it at Kimhae area from March, 1992 to June, 1994. The range of pH value in the precipitation at Kimhae is 3.45 to 6.80 and the average is pH 4.62, and the major anion components associated with acidity in the precipitation are $Cl^-, SO_4^{-2}, NO_3^-$. These distributions are to be expected the influence of industrialization such as, urbanization and construction of industrial complex at Kimhae area and the long range trasporting of air pollutants from China. The weather patterns governing the acid rain at Kimhae were classified broadly into four types(Cyclone(type I-a, type I-b), Migratory Anticyclone(type II), Tropical Cyclone(type III), Siberia High(type IV) and weather pattern which had the most occurrence frequency of acid rain was type I-a and the average pH value of precipitation in this pattern was 4.45, and we are found that the source area of air mass which was accompanied with high acidic precipitation in Kimhae was the central China include with Peking through the analysis of surface weather maps, 850 hPa wind fields, and the streamline analyses.

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온.습도 변화에 따른 양지의 손상원인 및 보존방안 연구 (The investigation of conservation methods and destruction regions of papers under the various temperature and humidity changes)

  • 이혜윤;정용재;이규식;한성희
    • 보존과학연구
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    • 통권21호
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    • pp.145-175
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    • 2000
  • To examine the method for preservation of papers, 9 kinds of papers were purchased and pretreated for 6 months with various artificial conditions which were controlled as 3 temperature classes($20^{\circ}C$, $80^{\circ}C$, $-20^{\circ}C$&$20^{\circ}C$) and 4 humidity classes(40%, 60%, 80%, 100%).Whiteness, acidity and folding endurance were measured to examine the state of papers pretreated under each condition. From the resultexamining the state, all the papers were best condition at low temperature($20^{\circ}C$) and low humidity(40%) and damaged at high temperature($80^{\circ}C$) and high humidity(100%).The values of whiteness, acidity, and folding endurance were measure din relation with deterioration of papers. According to damage of papers caused by the chemical agent, papers became to be acidic, increased color difference and reduced the force of folding endurance. The effect of change of temperature($-20^{\circ}C$&$20^{\circ}C$) on degradation of papers was not well acquired. Because the period of investigation was not long enough to acquire the data. So the more studies are needed to find the cause of damage of papers.

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토양산도 및 시비량 조절에 의한 연초의 Grey엽 발생방지 효과 (Effect of Lime Application and Fertilization Level on Prevention of Grey Tobacco Leaves)

  • 이철환;진정의;이동훈
    • 한국연초학회지
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    • 제16권2호
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    • pp.128-133
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    • 1994
  • This study was carried out to get agronomic information about the tobacco culture in paddy soil where incidence of grey tobacco leaves used to appearly uptake of iron, manganese and chlorine due to soil acidity and high water level. Application of lime to paddy soil(pH5.4-5.6) reduced content of iron, manganese known as proceeding materials giving rise to variegated grey tobacco after curing, compared with non-treatment. Grey leaves were found mainly at lower and middle stalk positions, and incidence of grey tobacco was lowered by application of lime in the well drained field but was not affected by level of fertilizer application. Amendment of soil acidity by lime tended to decrease chlorine and manganese content in leaves. Nicotine and mangenese content of leaves were lowered by reduction of one-quarter fertilizer level. In case of lime treatment, increase of yield reached to 4-6% comparing with those of non-treatment but price per kg was not affected. Reduction of N fertilizer level to three-quarters had the equal yield but high quality of leaf comparing with standard fertilization in paddy field.

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초기 임신 기간중 흰쥐 자궁 내막조직의 Phosphatase 활성에 관하여 (On the Activity of Phosphatase in the Endometrium of the Rat Uterus During Early Pregnancy)

  • 김성례;조완규
    • Clinical and Experimental Reproductive Medicine
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    • 제8권2호
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    • pp.1-11
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    • 1981
  • The quantitative analyses of the phosphatase activity in the endometrium of the rat ovariectomized on Day 2 of pregnancy was carried out in comparison with the intact one, in order to investigate the hormonal dependency of the uterus prior to the implantation, and to study the phosphatase activity in the endometrial tissues in vitro incubated in different acidity of the medium. The results obtained were as follows: 1. The activity of the total phosphatase was the highest at Day 3 of pregnancy of the intact animals irrespective of acidity of the medium. However, the ovariectomized rat showed its peak somewhat delayed. The time of the highest activity of the enzymes was matched with the time of high secretion of the ovarian hormones. 2. The activity of acid phosphatase in the endometrium was twice or four times as much high as that of neutral or alkaline phosphatase, respectively. 3. The activity of alkaline phosphatase was rather steady in Day 3 through Day 5 of the pregnancy of the rat intact or ovariectomized but with low level compared to those of other phosphatase. 4. The present re~lt indicated more important role by $Mg^{2+}$-dependent phosphatase than by $K^+$-dependent one for the preparation for decidualization.

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오렌지 및 포도 농축액과 과당의 첨가량에 따른 soy kefir의 품질특성 (The Effects of the Addition of Orange and Grape Concentrates, and Fructose on the Quality Characteristics of Soy Kefir)

  • 이숙영;나성훈;이시영
    • 한국식생활문화학회지
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    • 제21권3호
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    • pp.330-335
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    • 2006
  • The objectives of this study were to characterize the quality of soy kefir made with soymilk in combination with fructose (5%, 10%) and one of the extracts from orange (10%, 15%) and grape (5%, 10%) with differently adjusted amounts as defendant variables. The lactic acid bacteria, yeast and total microbial counts of soy kefir were respectively $1.3{\times}10^7$ CFU/ml, $1.6{\times}10^8$ CFU/ml, $1.5{\times}10^8$ CFU/ml, soy kefir was propered to drink. pH of soy kefir mixed by orange and grape extracts was decreased significantly according to add fructose 5%. Acidity became significantly high when orange and grape extracts were added, which means acidity showed similar tendency in the opposite direction. The saccharinity of soy kefir was not significantly in orange extract, but soy kefir added fructose 10% was high more than fructose 5% in grape extract. In sensory evaluation, soy kefirs added orange extract 15%, fructose 5% and grape extract 10%, fructose 5% were estimated highly on color, astrigent taste, sour taste, mouth feel and overall quality.