Skip to main content

Advertisement

Log in

Electromagnetic Heating for Industrial Kilning of Malt: a Feasibility Study

  • Original Paper
  • Published:
Food and Bioprocess Technology Aims and scope Submit manuscript

Abstract

Industrial malting operations use ∼800 kWh/t of energy to produce the heat required to kiln malt. Electromagnetic heating technologies are suggested as a way to potentially improve the energy efficiency of the kilning processing. In this work, the potential for using electromagnetic heating to dry malt to commercially acceptable moisture levels whilst preserving the activity of enzymes critical for downstream brewing processes is investigated. The 2450 MHz bulk dielectric properties of malt at moisture contents consistent with those occurring at different points in the kilning process are evaluated; 12% is shown to be a critical moisture level below which drying becomes more energy intensive. Calculated penetration depths of electromagnetic energy in malt at radio frequency are 100-fold higher than at microwave frequencies, showing a significant advantage for commercial-scale batch processing. The moisture contents and alpha and beta amylase activity of malt subjected to RF heating at different temperatures, treatment times and RF energy inputs in the intermediate and bound water drying regions were determined. It is shown for the first time that whilst significantly reduced process times are attainable, significant energy efficiency improvements compared to conventional kilning can only be achieved at higher product temperatures and thus at the expense of enzyme survival. It is suggested that RF heating may be feasible where higher bulk temperatures are not critical for downstream use of the material or when used in hybrid systems.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9
Fig. 10
Fig. 11
Fig. 12

Similar content being viewed by others

References

  • Bala, B. K. (1983). Deep bed drying of malt. Faculty of Science: Agriculture and Engineering Newcastle University.

    Google Scholar 

  • Bathgate, G. (1973). Biochemistry of malt kilning. Brewers digest., 48, 60–65.

    CAS  Google Scholar 

  • Beddington J (2009) Food, energy, water and the climate: a perfect storm of global events. In: Lecture to Sustainable Development UK 09 Conference.

  • Betz, F. (2003). Managing technological innovation: competitive advantage from change. John Wiley & Sons.

  • Briggs, D., Hough, J., Stevens, R., & Young, T. (1981). Malting and brewing science: malt and sweet wort (Vol. 1, Springer US).

    Google Scholar 

  • Buttress, A., Jones, A., & Kingman, S. (2015). Microwave processing of cement and concrete materials—towards an industrial reality? Cement and Concrete Research., 68, 112–123.

    Article  CAS  Google Scholar 

  • CarbonTrust (2011) Maltings industrial energy efficiency. In: Industrial energy efficiency accelerator. vol CTG053. p^pp.

  • Clarke RN, Gregory AP, Cannell D, Patrick M, Wylie S, Youngs I & Hill G (2003) A guide to the characterisation of dielectric materials at RF and microwave frequencies. Institute of Measurement and Control, National Physical Laboratory

  • DEFRA (2013) Industry agree stretching energy efficiency targets with government. Available at https://www.gov.uk/government/news/industry-agree-stretching-energy-efficiency-targets-with-government.

  • Engen, G. F., & Hoer, C. A. (1979). Thru-reflect-line: an improved technique for calibrating the dual six-port automatic network analyzer. Microwave Theory and Techniques, IEEE Transactions on., 27(12), 987–993.

    Article  Google Scholar 

  • European Brewery Convention (2000) Malting technology. Getränke-Fachverlag Hans Carl,

  • Filly, A., Fernandez, X., Minuti, M., Visinoni, F., Cravotto, G., & Chemat, F. (2014). Solvent-free microwave extraction of essential oil from aromatic herbs: from laboratory to pilot and industrial scale. Food Chemistry., 150, 193–198.

    Article  CAS  Google Scholar 

  • Gebremariam, M. M., Zarnkow, M., & Becker, T. (2012). Effect of drying temperature and time on alpha-amylase, beta-amylase, limit dextrinase activities and dimethyl sulphide level of teff (Eragrostis tef) malt. Food and Bioprocess Technology., 6(12), 3462–3472.

    Article  Google Scholar 

  • Hardwick W (1994) Handbook of brewing. CRC

  • Henry, F., Gaudillat, M., Costa, L. C., & Lakkis, F. (2003). Free and/or bound water by dielectric measurements. Food Chemistry., 82(1), 29–34.

    Article  CAS  Google Scholar 

  • Jones, D. A., Lelyveld, T. P., Mavrofidis, S. D., Kingman, S. W., & Miles, N. J. (2002). Microwave heating applications in environmental engineering—a review. Resources, Conservation and Recycling., 34(2), 75–90.

    Article  Google Scholar 

  • Kaatze, U. (1989). Complex permittivity of water as a function of frequency and temperature. Journal of Chemical and Engineering Data., 34(4), 371–374.

    Article  CAS  Google Scholar 

  • Kappe, C. O. (2013). Microwave effects in organic synthesis: myth or reality? Angewandte Chemie International Edition., 52(4), 1088–1094.

    Article  CAS  Google Scholar 

  • Kraszewski, A., & Nelson, S. (1989). Composite model of the complex permittivity of cereal grain. Journal of Agricultural Engineering Research., 43, 211–219.

    Article  Google Scholar 

  • Kunze, W., Wainwright, T., & Mieth, H. (1999). Technology brewing and malting (Vol. 669). Germany: Vlb Berlin.

    Google Scholar 

  • Lu, Z., Lanagan, M., Manias, E., & Macdonald, D. D. (2009). Two-port transmission line technique for dielectric property characterization of polymer electrolyte membranes. The Journal of Physical Chemistry B., 113(41), 13551–13559.

    Article  CAS  Google Scholar 

  • Mehdizadeh M (2015) Microwave/RF applicators and probes: for material heating, sensing, and plasma generation. William Andrew,

  • Meredith RJ (1998) Engineers’ handbook of industrial microwave heating. Institution of Electrical Engineers,

  • Metaxas AA & Meredith RJ (1983) Industrial microwave heating.

  • Muller, R. (2000). A mathematical model of the formation of fermentable sugars from starch hydrolysis during high-temperature mashing. Enzyme and microbial technology., 27(3), 337–344.

    Article  CAS  Google Scholar 

  • Nelson, S. (2008). Dielectric properties of agricultural products and some applications. Research in Agricultural Engineering., 54(2), 104–112.

    Google Scholar 

  • Nelson, S. O., & Stetson, L. E. (1976). Frequency and moisture dependence of the dielectric properties of hard red winter wheat. Journal of Agricultural Engineering Research., 21(2), 181–192.

    Article  Google Scholar 

  • Nelson, S. O., & Trabelsi, S. (2006). Dielectric spectroscopy of wheat from 10 MHz to 1.8 GHz. Measurement Science and Technology., 17(8), 2294.

    Article  CAS  Google Scholar 

  • O’Rourke, T. (2002). Malt specifications & brewing performance. Brew Int., 2(10), 27–30.

    Google Scholar 

  • Pethig, R., & Kell, D. B. (1987). The passive electrical properties of biological systems: their significance in physiology, biophysics and biotechnology. Physics in medicine and biology., 32(8), 933.

    Article  CAS  Google Scholar 

  • Raghavan, G., Rennie, T., Sunjka, P., Orsat, V., Phaphuangwittayakul, W., & Terdtoon, P. (2005). Overview of new techniques for drying biological materials with emphasis on energy aspects. Brazilian Journal of Chemical Engineering., 22(2), 195–201.

    Article  CAS  Google Scholar 

  • Serdyuk, V. M. (2008). Dielectric study of bound water in grain at radio and microwave frequencies. Progress In Electromagnetics Research., 84, 379–406.

    Article  Google Scholar 

  • Sopanen, T., & Laurière, C. (1989). Release and activity of bound β-amylase in a germinating barley grain. Plant Physiology., 89(1), 244–249.

    Article  CAS  Google Scholar 

  • Tassou, S. A., Kolokotroni, M., Gowreesunker, B., Stojceska, V., Azapagic, A., Fryer, P., & Bakalis, S. (2014). Energy demand and reduction opportunities in the UK food chain. Proceedings of the ICE-Energy., 167(3), 162–170.

    Google Scholar 

  • Thostenson, E., & Chou, T.-W. (1999). Microwave processing: fundamentals and applications. Composites Part A: Applied Science and Manufacturing., 30(9), 1055–1071.

    Article  Google Scholar 

  • Trabelsi, S., Kraszewski, A. W., & Nelson, S. O. (2001). New calibration technique for microwave moisture sensors. Instrumentation and Measurement, IEEE Transactions on., 50(4), 877–881.

    Article  Google Scholar 

  • Trabelsi, S., & Nelson, S. O. (2003). Free-space measurement of dielectric properties of cereal grain and oilseed at microwave frequencies. Measurement Science and Technology., 14(5), 589.

    Article  CAS  Google Scholar 

  • Trabelsi, S., & Nelson, S. O. (2006). Temperature-dependent behaviour of dielectric properties of bound water in grain at microwave frequencies. Measurement Science and Technology., 17(8), 2289.

    Article  CAS  Google Scholar 

  • Trabelsi, S., & Nelson, S. O. (2007). Unified microwave moisture sensing technique for grain and seed. Measurement Science and Technology., 18(4), 997.

    Article  CAS  Google Scholar 

  • Venkatesh, M., & Raghavan, G. (2005). An overview of dielectric properties measuring techniques. Canadian biosystems engineering., 47(7), 15–30.

    Google Scholar 

  • Weir, W. B. (1974). Automatic measurement of complex dielectric constant and permeability at microwave frequencies. Proceedings of the IEEE., 62(1), 33–36.

    Article  Google Scholar 

  • Whitehurst RJ & Van Oort M (2010) Enzymes in food technology, vol 388. Wiley Online Library,

Download references

Acknowledgements

The authors would like to express their gratitude to Muntons PLC for sponsoring this work.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to R. S. Ferrari-John.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ferrari-John, R.S., Katrib, J., Zerva, E. et al. Electromagnetic Heating for Industrial Kilning of Malt: a Feasibility Study. Food Bioprocess Technol 10, 687–698 (2017). https://doi.org/10.1007/s11947-016-1849-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11947-016-1849-0

Keywords

Navigation