• 제목/요약/키워드: accelerated heat-treatment

검색결과 82건 처리시간 0.017초

침지액의 NaOH와 NaCl의 농도 및 계란 침지기간이 계란 피단의 완성도에 미치는 영향 (Effect of Concentration of NaOH and NaCl in Dipping Solution and Dipping Period of Egg in Completeness of Egg Pidan)

  • 신택순;조성근;이홍구;조병욱;강한석;박현철;배석현;김윤석;김병우
    • 농업생명과학연구
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    • 제46권6호
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    • pp.117-126
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    • 2012
  • 본 실험은 계란의 과잉생산에 따른 여러 가지의 문제점을 해결하고 사육 농가의 소득을 증대하기 위해 계란으로 피단을 제조하는 방법을 실험하였다. NaOH의 농도를 3, 5, 7%로 기준하고 NaCl의 농도를 5, 10, 15, 20%로 기준하여 침지액을 제조하여 2일 간격으로 14일간 실험하였다. 침지액의 pH는 NaOH의 농도가 높을수록, 그리고 침지기간이 경과할수록 피단제조용 침지액의 pH는 증가하였고, NaCl의 농도가 높을수록 감소하는 경향이 나타났다. 난황의 pH는 NaOH의 농도가 진할수록 증가하였으나, NaCl의 농도에 따라서는 차이가 나타나지 않았다. NaOH와 NaCl의 농도가 높을수록 난황과 난백 침투속도는 빨라지는 것으로 나타났다. NaOH의 농도가 3%일 때 14일까지도 난백의 수양화가 되지 않았으나, 5%일 때는 11~12일째에, 7%일 때는 8~10일째에 각각 수양화가 발생하였다. 수양화가 되었을 때 난백의 pH는 11.8~12.0으로 조사되었다. NaOH의 농도가 3%일때는 12~14일 정도, 5%일 때는 10일 정도, 7%일 때는 6~7일 정도 침지 후 열처리를 하면 피단이 완성되었다. NaOH의 농도가 높을수록 침지기간 및 제조기간은 단축하였으나, 피단 난백의 수양화가 빠르게 진행되는 것이 큰 단점으로 나타났다. 따라서 NaOH가 3~5%정도가 알맞다고 생각되며, NaCl의 농도는 침지기간에는 무관하나 염도에 영향을 미치므로 5~10%정도 범위에서 조절하는 것이 적당하고 15~20%일 경우에는 염도가 높아 기호도가 떨어졌다.

Shalf Life Enhancement of Minimally Processed Fruits and Vegetables

  • Kim, Dong-Man
    • 한국식품저장유통학회:학술대회논문집
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    • 한국식품저장유통학회 1993년도 정기총회 및 제3차 학술발표회
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    • pp.6-9
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    • 1993
  • According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. According to changes in population, economic conditions, life-stile and eating habits, the frui ts and vegetables market wi 11 be shi fted from processed (i. e. , canned) to fresh. Undressed fresh produce, consisting of washed, disinfected and peeled fruits and vegetables that either sliced or grated, are currently increased in demand by retail and institutional market which use them as salad components or in ready-to use foods, Main attributes of minimally processed fruits and vegetables are convenience and fresh-like quality. Minimally processed Products readily deteriorate in quality, especially color and texture, as a result of endogeneous enzyme enhanced respiration and microorganisms which lead to reduced shelf Iife. Thus. to prevent these undesirable changes , val'ious techniques such as controlled atmosphere (CA) storage, modified atmosphere OIA) storage, including vacuum packaging have been receiving considerable attention, Although milch research has been done to find optimal conditions for whole intact frui ts and vegetables, only limi ted information is avai lable on fresh cut. and other minimally processed products. 81 iced frui ts exhibi t increas~d ethylene production and respiration compal'ed to whole f, 'uits during distribution in response to tissue damage. As a result, accelerated senescence and enzymatic browning OCCUI', Recent l'esearch on minimally processed fl'uits and vegetables has mainly focused on methods to inhibit browning, due to ban on use of sulfur dioxide, In order to retard or prevent these physiological changes, val'ious al ternatives, reducing agents. acidulants, chelating agents and inol'ganic sal ts have been evaluated for use on fresh cut fl'ui ts. Al though some agents were effective replacement for sulfur dioxide. consum$\textregistered$I'S demandless use of chemical on such products. Shel~ life of minimally processed products has been extended by inhibition of metabolic reactions associated with loss of quality and by inhibition of aerobic spoilage caused by wide variety of microorganisms. Appl ication of ~I.-\ packaging, including vacuum packaging, retards the rate of respiration, prevents growth of aerobic spoilage organisms, inhibits oxidation and color deterioration. Tissue softening is another major problem in minimally processed products because enzymes re 1 a ted to ce 11 wa 11 degrada t i on are not inactivated. Various treatments have been investigated for retardation of the softening of sliced products. Some studies have concentrated on the application of an active packaging system with ~I, l. packaging and calcium infi 1 tration as possible measures to retain firmness of processed products. In my opinion, one important step for production of minimally processed frui ts wi th favorabl e color of cut surface and firm texture is the selection of better cultivar. As the view, changing tendency of fresh color by apple cultivars and relationship between the tendency and PPO activity will be discussed in the seminar. In addition to the topic, research result on quality enhancement of fresh apple slices by heat shock treatment will be introduced.

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