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  • autolysis

    I need how much is the specific heat of yeast to design a heater to autolyse it.
    Carlos A. Felix
    M. Brewer

  • #2
    Thermodynamics

    I have never seen a specific heat value for yeast.
    So you may have to determine it yourself.

    You could take a known volume (mass) of yeast heat it to a measured temperature. Combine the yeast sample in known volume (mass) of water at a different temperature in a well insulated cup. record the temperature change after combining once equilibrium is reached. Then solve for the specific heat of yeast using the equation q=MC "delta T" where q is heat, m= mass, c= specific heat of the substance, and delta T is the change in temperature. The specific heat would be different depending on the beer the yeast came from, the cell density of the yeast and so on. I am not sure why you would need the specific heat to autolyse yeast? Just heat the yeast to the autolysis temperature and hold until its all autolyzed. I think some people just use their kettle to lyse the yeast before disposal if need be. Chemical lysis is also another option. You could also emprirically determine the most effective time and temperature by doing some experiments and viability counts with methylene blue...or a flow cytometer for viability if you happen to have one.

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    • #3
      I want to build a heater to autolyse yeast, a 100 hl/hr heater as a heat exchanger: vapor/yeast
      Carlos A. Felix
      M. Brewer

      Comment


      • #4
        To design and make a heat exchanger to autolyse I need some data like specific heat of yeast..
        Carlos A. Felix
        M. Brewer

        Comment


        • #5
          now thats some serious engineering

          I did find a paper on the web, I don't subscribe to this journal however. Please see the abstract below

          Drying of baker's yeast in batch fluidized bed

          Mustafa Türkera, , Ali Kanaryaa, Uğur Yüzgeçb, , , Hamdi Kapucua, and Zafer Şenalpc

          aPakmaya, P.O. Box 149, 41001, Kocaeli, Turkey

          bDepartment of Electronics & Telecommunications Engineering Kocaeli University, 41040, Kocaeli, Turkey

          cGebze Institute of Technology, Gebze, Kocaeli, Turkey


          Received 11 June 2005; revised 9 December 2005; accepted 10 January 2006. Available online 7 April 2006.




          References and further reading may be available for this article. To view references and further reading you must purchase this article.


          Abstract
          A drying model was developed for production scale fluid bed drying of granular baker's yeast. In the model, heat capacity of the dryer and the product entrained through cyclone and heat transfer from the dryer to environment were also taken into account to improve the predictive capacity of the model. Kinetic model based on the assumption that the resistances to mass transfer during drying lie not inside but liquid film around the granules was integrated into material and energy balances. Drying rate constant was determined from experimental results at constant air inlet flow rate and temperature but at varying dryer loadings. Its magnitude was found as function of amount of product loaded into the dryer. Simulations were performed for two different granule sizes and good correspondence was found between model predictions and experimental measurements for small granule sizes. For larger granules, deviations between simulations and measurements were observed and this was attributed to diffusive transport limitation of moisture inside granules, which requires mathematical description of spatial distribution of moisture and temperature inside the particles. The model can be used for design, optimization and control of drying processes for various applications.

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