Thawing of food products by radiofrequency
- How does it work?
- What can it be used for?
- What can it not be used for?
- Related Facilities
- Further Information
|Key words||Thawing, tempering, defrosting, radiofrequency, electromagnetic radiation, heat transfer, meat, pork, beef, fish, seafood, vegetal-type products, ready meals|
How does it work?
|Primary objective||Rapid thawing of meat and seafood products enhancing the product freshness quality.|
|Working principle|| Radiofrequency (RF) is a form of dielectric heating, and implies heating foods by dipole rotation and ionic polarisation. Compared to Microwave heating, RF has been proposed to be more suitable for industrial heating of meats because of its greater penetration depths (1).
In conventional thawing methods used in the meat industry the product is placed in contact with air or water at controlled temperatures, with air being the predominant method used. This is time consuming.
By radiofrequency treatment, thawing meat blocks to within a target temperature range of -1 to +5ºC is feasible. A 85 fold reduction in thawing time (3) and a 30 fold reduction in tempering time (2) has been reported when compared to conventional methods. Leaner blends and higher power treatments produced the most efficient RF tempering process (4).
The most common methods used in seafood industry are air based or water systems, using either immersion in tanks or spraying with water. Water systems have several problems i.e. under-thawed product and yield losses, or over-thawed product involving problems with texture loss and decreased freshness as well as excessive water consumption.
Using radiofrequency 5cm blocks of fish can be thawed in 15 to 45 minutes. For final temperatures near the thawing point of seafood (typically -1°C), the two frequencies offered by microwave processing (2450 MHz and 915 MHz) are no longer adequate as they can create uneven temperature distributions and result in poor quality products. At the lower frequencies of RF, penetration of the RF energy into foods is much greater and enables the temperature of blocks to increase from -20° C to -2 or 0°C. As a result, the thawing process can be shortened.
|Important process parameters||frequency, power level, distance between electrodes, application time|
|Important product parameters||degree of comminution, composition (lean/fat ratio), geometry (preferably cutted in blocks), dielectric constants|
What can it be used for?
|Operations||thawing, tempering, defrosting, heating|
|Solutions for short comings||
What can it NOT be used for?
|Risks or hazards||
|Maturity|| RF is a mature technology and industrial applications are known since the 80’s. Industrial application for thawing is still not wide spread.
Bottlenecks for a wider spreading of industrial application of RF for seafood thawing are high capital costs and personnel maintanence-related costs (8).
|Modularity /Implementation|| Batch and continuous RF thawing methods can be adapted to an existing line. Depending on the application, various radiofrequency modules can be implemented.
For seafood products: batch RF systems operate from 40 to 350 kg/hour whilst continuous RF systems can operate from 900 to 3000 kg/hour (8).
|Consumer aspects||No information available. No problems expected.|
Facilities that might be interesting for you
|Institutes||IRTA, SP, Wageningen UR - FBR, Nofima, Matís|
|Companies||Sairem, Stalam, Petrie Technology, Keam Holdem Associates, NSG Environmental - NIS|
|References|| 1. Brunton N.P., Lyng J.G., Li W., Cronin D.A., Morgan D.J., McKenna B.. Effect of radio frequency (RF) heating on the texture, colour and sensory properties of a comminuted pork meat product; Food Research International, Volume 38, Issue 3, April 2005, p. 337-344
2. Farag K. W., Lyng J. G., Morgan D. J., Cronin, D. A. Tempering and thawing rate effect on drip loss of beef meat. Meat Science 83 (2), 2009, p. 278-284
3. Farag K.W., Lyng J.G., Morgan D.J., Cronin D.A. A Comparison of Conventional and Radio Frequency Thawing of Beef Meats: Effects on Product Temperature distribution. Meat Science 80, 2008, p.488–495
4. Farag K.W, Marra F., Lyng J.G. Morgan D. J, Cronin D. A. Temperature Changes and Power Consumption During Radio Frequency Tempering of Beef Lean/Fat Formulations. Food and Bioprocess Technology 3(5), 2010, p.732-740
5. Thawing and tempering. In Meat Refrigeration (p. 159–187). Cambridge: Woodhead Publishing. James, S. J., & James, C., 2002.
6. Farag K.W., Duggan E., Morgan D.J., Cronin D.A., Lyng J.G. A comparison of conventional and radio frequency defrosting of lean beef meats: Effects on water binding characteristics. Meat Sci., 2009 May 21.
7. Keam Holdem, 2004. Radio frequency tempering of frozen fish. Application note KHA-0302.
8. Seafood thawing, Feb. 2008. Seafish Research & Development. Michaela Archer, Mark Edmonds and Martin George. http://www.seafish.org/media/Publications/SR598_Thawing.pdf
frequency, power level, distance between electrodes, application time degree of comminution, composition (lean/fat ratio), geometry (preferably cutted in blocks), dielectric constants Electro-Magnetic equipment 2.2.3 physical structure forming other Sciencedirect, Springerlink, Wiley, internal knowledge Search terms: thawing, tempering, defrosting, radiofrequency, meat, frozen beef WikiSysop :Template:Review document :Template:Review status