Tatiana Koutchma Ph.D., Research Scientist, Agriculture and Agri-Food Canada
With the high growth of cold preservation and sanitation markets, light technologies are now emerging in food production both as mild thermal and non-thermal techniques of preserving food and eliminating food pathogens due to their unique effects on microorganisms and minimal impact on food quality. Food researchers, technology providers, and food manufacturers currently explore a few techniques based on the unique properties of light to interact with foods and food related micro-flora. This includes continuous and pulsed ultraviolet light (UV), pulsed light (PL), and light emitting diodes (LEDs). Each technology utilizes a different type of light that is generated in various forms and demonstrates different efficacy in terms of results and applications. In addition to improvement of food preservation operations, creating new functional properties, and dry sanitation, further development and commercialization of light technologies have much to offer for the sustainable development of industry. This article will briefly review the basics and sources of light technologies and present the pros and cons of the potential applications and available equipment.
Continuous UV Light
UV light is known as a portion of the electromagnetic spectrum between 100 and 400nm corresponding to photon energies from 124 eV to 3 eV. The wavelength of UV light is shorter than the violet end of the visible spectrum, but longer than the X-ray. Because of low inherent energy of photons, the penetration of UV photons is low in comparison with ionising radiation and UV light belongs to non-ionizing radiation. UV-light range is further divided into UV-A, -B, and -C sub-diapasons that characterized by various wavelengths and energy levels of photons, and thus differ in produced effects. Most people are familiar with UVB and UVA from sunlight as causing suntan and sunburn.