• Title/Summary/Keyword: pH 영향

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Studies on the Amylase Production by Bacteria (세균(細菌)에 의(依)한 Amylase생산(生産)에 관한 연구(硏究))

  • Park, Yoon-Joong
    • Applied Biological Chemistry
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    • v.13 no.2
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    • pp.153-170
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    • 1970
  • 1. Isolation and identification of amylase-producing bacteria. The powerful strain A-12 and S-8 were respectively isolated from air and soil after screening a large number of amylase-producing bacteria. Their bacterial characteristics have been investigated and it has been found that all characteristics of strain A-12 and S-8 are similar to Bac. subtilis of Bergey's manual except for the acid formation from a few carbohydrates and the citrate utilization, i.e., the strain A-12 shows negative in the citrate utilization, and the acid formation from arabinose and xylose, S-8 shows negative in the acid formation from xylose. 2. Amylase production by Liquid cultures with solid materials. Several conditions for amylase production by strain A-12 in stationary cultures have been studied. The results obtained are as follows. (1) The optimum conditions are:temperature $35^{\circ}C$, initial pH 6.5 to 7.0 and incubation time 3 to 4 days. (2) The amylase production is not affected by the preservation period of the stock cultures. (3) Among the various solid material, the defatted soy bean is found to be the best for t1e amylase production. However, the alkali treatment of the defatted soy bean gives no effect contrary to the cage of defatted rape seed. The addition of soluble starch to the alkali extract of defatted soy bean shows the increased amylase production. (4) Up to 1% addition of ethanol to carbon dificient media gives the improved amylase production, whereas the above effect is not found in the case of carbon rich media. (5) The amylase production can be increased 2.5 times when 10% of defatted soy bean is admixed to cheaply available wheat bran. (6) The excellent effect is found for amylase production when 20% of wheat bran is admixed to defatted dry milk which is a poor medium. The activity is found to be $D^{40^{\circ}}_{30'}$ 7,000(L.S.V. 1,800) in 10% medium. (7) No significant effect is observed due to the addition of various inorganic salts. 3. Amylase production by solid cultures. Several conditions for amylase production by strain A-12 in wheat bran cultures have been studied and the results obtained are as follows. (1) The optimum conditions: are temperature $33^{\circ}C$, incubation lime 2 days, water content added 150 to 175% and the thickness of the medium 1.5cm, The activity is found to be $D^{40^{\circ}}_{30'}$ 36,000(L.S.V. 15,000) (2) No significant effect is found in the case of the additions of various organic and inorganic substances.

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Study on BMI, Dietary Behavior, and Nutrient Intake Status According to Frequency of Breakfast Intake in Female College Students in Chuncheon Area (춘천지역 일부 여대생의 아침식사 빈도에 따른 BMI, 식행동 및 영양소 섭취상태)

  • Kim, Yoon-Sun;Kim, Bok-Ran
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.10
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    • pp.1234-1242
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    • 2017
  • The purpose of this study was to investigate BMI, dietary behavior, and nutrient intake status according to frequency of breakfast intake in female college students (n=253) in Chuncheon area. This study was conducted by employing a self-administered questionnaire. Dietary assessment was measured by the 24-h recall method. The subjects were divided into two groups by frequency of breakfast: Five to seven times per week (eating breakfast group, n=139) and none to four times per week (skipping breakfast group, n=114). The living with parents group showed significant high frequency of breakfast intake, whereas the self-boarding group showed significant low frequency of breakfast intake. The body image satisfaction score of the 5~7 times/week group was higher than that of the 0~4 times/week group. The average height and weight of the 5~7 times/week group were $161.0{\pm}0.1cm$ and $52.6{\pm}7.6kg$, respectively, whereas those of the 0~4 times/week group were $160.7{\pm}0.1cm$ and $57.1{\pm}11.8kg$, respectively. The average body mass index (BMI) values of the 5~7 times/week and 0~4 times/week groups were $19.8{\pm}1.9kg/m^2$ and $21.5{\pm}3.4kg/m^2$, respectively. The dietary behavior score of the 5~7 times/week group was higher than that of the 0~4 times/week group. The daily averages for energy, carbohydrate, and protein intakes in the 5~7 times/week group were significantly higher than those of the 0~4 times/week group. Intakes of vitamin A, vitamin $B_1$, vitamin $B_2$, niacin, vitamin $B_6$, P, Zn, and cholesterol in the 5~7 times/week group were significantly higher than those of the 0~4 times/week group. Multiple regression analysis revealed that resident type was the most significant variable associated with breakfast intake frequency. Therefore, strengthening dietary education programs that largely focus on resident type will greatly contribute to prevent skipping breakfast.

Effect of Sanitation Treatment of Extending Shelf-life on Fresh Poultry Meats (계육(鷄肉)의 유통기간연장(流通期間延長)을 위(爲)한 위생처리방법(衛生處理方法)에 관(關)한 연구(硏究))

  • Cho, M.J.;Jang, P.H.;Park, K.B.;Lee, B.M.
    • Korean Journal of Food Science and Technology
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    • v.14 no.4
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    • pp.291-300
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    • 1982
  • In order to develop effective and simple sanitation method for the extention of shelf-life of fresh poultry meat, the effect of sanitizers, sanitation methods and packaging materials on the extention of shelf-life of poultry meats was observed at the $4^{\circ}C$ and room temp$(10{\sim}20^{\circ}C)$. The results are summarized as follows: 1. The autochonous skin microflora of poultry, before processing, were believed to be removed or killed during the scalding and plucking, and exposed dermal tissue was contaminated by microorganisms from the subsequent stages of processing. 2. In the final stage of poultry processing, total viable counts of microorganisms and coliforms were averaged to $3.5{\times}10^4/cm^2$ and $400/cm^2$, respectively. 3. The refrigerated shelf-life of fresh whole poultry carcasses at $3\;to\;4^{\circ}C$ was extended to 7 to 16 days compared to control with the various treatments of some sanitizers by dipping freshly chilled carcasses for 5 min or spraying 1 liter of sanitizers per carcasses. In the case of storage at $10\;to\;15^{\circ}C$, the shelf-life of poultry carcasses was extended to one to two days by the sanitation treatments compared to control. 4. Spraying sanitation was more effective than dipping sanitation, and 5 minutes dipping and one liter spraying per carcass were enough for effective sanitation of poultry carcasses in most sanitizers. 5. The packaging with an oxygen impermeable polyvinylidene chloride extended the shelf-life to 10 days and 5 days with polyethylene compared to control. When poultry carcasses were sanitized by continuous spraying with one liter of 30 ppm of chlorine and another one liter of 5% of potassium sorbate, packaged with polyvinylidene chlorlde were extended to about 30 days compared to control.

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