IDEAS home Printed from https://ideas.repec.org/a/caa/jnlpse/v64y2018i10id482-2018-pse.html
   My bibliography  Save this article

Effect of drying temperature on the content and composition of hop oils

Author

Listed:
  • Adolf RYBKA

    (Department of Agricultural Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic)

  • Karel KROFTA

    (Hop Research Institute Co., Ltd., Žatec, Czech Republic)

  • Petr HEŘMÁNEK

    (Department of Agricultural Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic)

  • Ivo HONZÍK

    (Department of Agricultural Machines, Faculty of Engineering, Czech University of Life Sciences Prague, Prague, Czech Republic)

  • Jaroslav POKORNÝ

    (Hop Research Institute Co., Ltd., Žatec, Czech Republic)

Abstract

In terms of content, the paper is aimed at analysing and comparing the quality of fresh green hops and hops dried at two drying temperatures - 55°C (in the traditional manner) and 40°C (using the so-called gentle drying), regarding the maximum preservation of hop essential oils. Comparative experiments were carried out in an experimental chamber dryer with two Czech hop cultivars Saaz and Harmonie. The moisture content of hops at the beginning of drying was 75% and at the end of drying it was 9-10%. By lowering the drying temperature from 55°C to 40°C, the drying time in cv. Saaz prolonged from 8 to 10 h and for the cv. Harmonie from 9 h to 12 h. Compared to fresh hops, the amount of hop oils decreased by 10% when dried at 40°C and by 36% (cv. Saaz) and 43% (cv. Harmonie) when dried at 55°C. These losses can be considered significant, especially for hops intended for late and dry beer hopping. However, by drying the hops at different temperatures, the ratios between various components of the essential oils and thus also their sensory character remained approximately unchanged. Due to the reduced amount of essential oils, the drying effect reduces the intensity of hop aroma depending on the drying temperature.

Suggested Citation

  • Adolf RYBKA & Karel KROFTA & Petr HEŘMÁNEK & Ivo HONZÍK & Jaroslav POKORNÝ, 2018. "Effect of drying temperature on the content and composition of hop oils," Plant, Soil and Environment, Czech Academy of Agricultural Sciences, vol. 64(10), pages 512-516.
    • Handle: RePEc:caa:jnlpse:v:64:y:2018:i:10:id:482-2018-pse
    DOI: 10.17221/482/2018-PSE
    as

    Download full text from publisher

    File URL: http://pse.agriculturejournals.cz/doi/10.17221/482/2018-PSE.html
    Download Restriction: free of charge
    File URL: http://pse.agriculturejournals.cz/doi/10.17221/482/2018-PSE.pdf
    Download Restriction: free of charge
    File URL: https://libkey.io/10.17221/482/2018-PSE?utm_source=ideas
    LibKey link: if access is restricted and if your library uses this service, LibKey will redirect you to where you can use your library subscription to access this item
    ---><---

    As the access to this document is restricted, you may want to search for a different version of it.

    References listed on IDEAS

    as
    1. I. Vitázek & J. Havelka, 2014. "Sorption isotherms of agricultural products," Research in Agricultural Engineering, Czech Academy of Agricultural Sciences, vol. 60(SpecialIs), pages 52-56.
    Full references (including those not matched with items on IDEAS)

    Most related items

    These are the items that most often cite the same works as this one and are cited by the same works as this one.
    1. Adolf Rybka & Petr Heřmánek & Ivo Honzík, 2021. "Effect of drying temperature in hop dryer on hop quality," Research in Agricultural Engineering, Czech Academy of Agricultural Sciences, vol. 67(1), pages 1-7.

    Corrections

    All material on this site has been provided by the respective publishers and authors. You can help correct errors and omissions. When requesting a correction, please mention this item's handle: RePEc:caa:jnlpse:v:64:y:2018:i:10:id:482-2018-pse. See general information about how to correct material in RePEc.

    If you have authored this item and are not yet registered with RePEc, we encourage you to do it here. This allows to link your profile to this item. It also allows you to accept potential citations to this item that we are uncertain about.

    If CitEc recognized a bibliographic reference but did not link an item in RePEc to it, you can help with this form .

    If you know of missing items citing this one, you can help us creating those links by adding the relevant references in the same way as above, for each refering item. If you are a registered author of this item, you may also want to check the "citations" tab in your RePEc Author Service profile, as there may be some citations waiting for confirmation.

    For technical questions regarding this item, or to correct its authors, title, abstract, bibliographic or download information, contact: Ivo Andrle (email available below). General contact details of provider: https://www.cazv.cz/en/home/ .

    Please note that corrections may take a couple of weeks to filter through the various RePEc services.

    IDEAS is a RePEc service. RePEc uses bibliographic data supplied by the respective publishers.