• Title/Summary/Keyword: Surface water heat exchanger

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Weight Loss Prediction by Operating Conditions of CA Storage (CA저장고의 작동 환경에 따른 감모율 예측)

  • Park, Chun Wan;Park, Seok Ho;Kim, Jin Se;Choi, Dong Soo;Kim, Yong Hun;Lee, Su Jang
    • Food Engineering Progress
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    • v.21 no.4
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    • pp.312-317
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    • 2017
  • Weight loss that influences quality and farmer incomes is affected by the storage environment of agricultural products. The interior of storage should be maintained at high humidity to prevent the weight loss of products which contain a lot of moisture. The research had constantly proceeded with change in the heat exchanger surface areas, humidity systems, and weight loss forecast to maintain high humidity within storage. Relative humidity that exerts an effect weight loss of crop is influenced by storage temperature, leak state, and volume of product. When weight loss is predicted, different conditions of these factors are derived. In case of CA storage, ways of forecasting the weight loss become easier compared to cold storage due to sealed storage with external environment during storage period. In this study, apples were stored in purge-type CA storage and weight loss has been predicted by using operating characteristics and environmental conditions. As a result, humidity variation in the storage fluctuates with the operation of the unit-cooler. Furthermore, unit-cooler operation factor is influenced by outside temperature and respiration heat. Prediction value of weight loss according to temperature and humidity has been most accurately predicted. Prediction value through defrosting water measured shows unit-cooler work quality. K-value needs verification to calculate the VPD method.

Pasteurization Efficiency of a Continuous Microwave HTST (연속식 마이크로파 고온단시간 살균시스템에서 우유의 살균효과)

  • Kim, Suk-Shin;Lee, Joo-Hee;Kim, Sang-Yong
    • Korean Journal of Food Science and Technology
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    • v.31 no.5
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    • pp.1392-1396
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    • 1999
  • This work was to apply the microwave energy to HTST pasteurization of milk in order to prevent undesirable quality changes due to the fouling and overheating on the surface of heat exchanger. A continuous tubulartype microwave pasteurization system was designed using a domestic microwave oven(800w and 2,450MHz). Raw milk was HTST pasteurized$(at\;72^{circ}C\;for\;15\;sec)$ by three methods; by heating in a stainless steel tube immersed in a hot water bath(MP0), by heating in a microwave cavity to a desired temperature and then holding in a hot water bath(MP1) and by both heating and holding in a microwave cavity(MP2). The microbial quality based on the total plate count and Psychotrophic bacterial count was in the order MP0, MP2 and MP1 ; however, the quality difference was not significant(p<0.05) when the initial microbial numbers were involved in the statistical analysis. In addition, the three samples pasteurized by different methods showed the similar microbial quality based on the coliform count and phosphatase activity. The similar microbial quality of the three samples supports the potential use of microwave energy for the pasteurization of milk and other fluid food products.

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