Electromagnetic freezing
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Electromagnetic freezing applies magnetic fields during freezing to theoretically improve frozen food quality. While some companies have marketed electromagnetic freezers since the 2000s, a 2009 study found that the weak oscillating magnetic fields (OMFs) used in commercial freezers had no effect on ice crystal size, microstructure, color, texture, drip losses, or sensory attributes compared to static air freezing. A subsequent study also found no significant differences in drip loss, water-holding capacity, toughness, or whiteness between crab sticks frozen with varying strengths of OMFs compared to those frozen without OMFs. Future research with stronger or varying frequencies of OMFs across different foods and methods may be needed to fully understand their potential effects on
Electromagnetic freezing
- 1. Electromagnetic freezing FOOD 302 ADV FOOD PROCESSING Sineth Hasun
- 2. Introduction • Electromagnetic freezing basically involves applying a magnetic field during freezing. • Theoretically improve the quality of frozen food.
- 3. History of technology • Since the early 2000s, some companies have patented and marketed electromagnetic freezers. • ‘CAS (Cells Alive System) freezers - static and oscillating magnetic fields. (2007) • Proton freezers - static magnetic fields and electromagnetic fields. (2011) • Owada and Saito patents (2011) • enhance water supercooling • accelerate heat transfer • inhibit ice crystallization
- 4. Products on market • CAS Freezers • preventing the water molecules from clustering together • keeps the water molecules in motion • Reduce damage in the original texture, flavor and loss of moisture. • Proton freezers • Minimizes dripping and prevents food cell destruction. • preventing the forming of larger ice crystals
- 5. But • extremely low strength of the OMFs commonly applied in commercial freezers • In 2009 Study found that Weak OMF applied were exactly the same as those employed in commercial freezers. (Suzuki et al.) • Size and shape of ice crystals • Microstructure • Color and texture • Sensory evaluation • Drip losses
- 6. Electromagnetic freezing: Effects of weak oscillating magnetic fields on crab sticks Sample • Fresh crab sticks Instruments • CAS freezer • RC centrifuge • Spectrophotometer • Texture Analyser
- 7. Quality attributes Drip loss Describe the exudates from both fresh and frozen samples. Water-holding capacity The water-holding capacity (WHC) measured by using centrifugal force to remove the free and loosely bound water from the samples.
- 8. Toughness The toughness of the crab sticks was evaluated by a Warner-Bratzler test to determine the force needed to shear the sample. Whiteness Using spectrophotometer.
- 9. Results and discussion The samples frozen in static air presented the largest drip loss and toughness and the lowest water- holding capacity and whiteness. Toughness and whiteness in these samples were similar to those observed in CAS frozen crab sticks
- 11. Results Summery The oscillating magnetic fields applied during freezing did not avoid quality losses in crab sticks. These OMFs not only were incapable of avoiding quality losses but also were ineffective Strength or frequency, in reducing damage in the samples after thawing No significant differences were detected between samples frozen with (10%, 50%, and 100% CAS) and without (0% CAS) OMF application
- 12. Future application of the processing technology It should be desirable to perform investigations at much more wide ranges to have a complete view of the potential effects of OMFs on food freezing. Different food production Different methods
- 13. References • Owada, N., 2007. Highly-efficient freezing apparatus and high-efficient freezing method. US Patent 7237400 B2 • Owada, N., 2011. CAS technology: from storing fresh food to preserving medical resources. Organ Biol. 18 (1), 71e78. • Owada, N., Kurita, S., 2001. Super-quick freezing method and apparatus therefor. US Patent 6250087 B1. • Owada, N. Saito, S., 2010. Quick freezing apparatus and quick freezing method. US • Suzuki, T., Takeuchi, Y., Masuda, K., Watanabe, M., Shirakashi, R., Fukuda, Y., Tsuruta, T., Yamamoto, K., Koga, N., Hiruma, N., Ichioka, J., Takai, K., 2009. Experimental investigation of effectiveness of magnetic field on food freezing process. Trans. Jpn. Soc. Refrig. Air Cond. Eng. 26, 371e386
- 14. Questions