Commercial beef ranging from Hamburg steak to filet mignon has protein, iron, fat and cholesterol in abundance. The shelf life of beef depends on various factors such as the method of preparation and storage.
Research evidence shows storage temperature and storage time as the most important factors for retaining color and minimizing lipid oxidation in beef muscles (Jakobsen and Bertelsen, 2000).
The ideal storage temperature for raw beef is between 28F and 32F. It is for the simple reason that beef freezes at 32F and above 40F, undergoes rapid microbial spoilage, lipid oxidation, turns to dull brown or grey color from red and develops a sour reek (Boyer et al, 2009).
Numerous bacteria, such as Brochothrix, Carnobacterium, Lactobacillus, Pseudomonas and Shewanella that cause bad reek, off-flavors, discoloration and gaseous by-products have been isolated from refrigerated beef spoilage (Borch et al, 1996).
Changes in temperature within a display rack differ by region from the top of the rack through the space to the food display pan and hence, the temperature regulation (either manual or automatic) may not be accurate and perfect in a commercial food display rack. This is due to a continuous heat transfer process called radiation from the light source in the racks.
Published evidence points to the fact that temperature heterogeneity inside the display cabinets do exist, in spite of good display cabinet design and controlled operating conditions (Laguerre et al, 2011). Interestingly, research evidence also shows that food display cases exhibit very high temperature discrepancies and till date, the European Standard EN 441 admits large temperature intervals associated with the defrosting process contrary to the actual technology level (Clodic and Pan, 2002).
Moreover, the color and spectral characteristics of the electric light energy for radiation depends on the type of filament, coatings and temperature at which the filament operates.
Thus, the color and spectral characteristics of light is a temperature marker that can convey the radiation energy flow in a space. For instance, a lamp that emits white light with a higher proportion of spectral red is warm and a lamp that emits white light with a higher proportion of spectral blue is cool. Infrared and ultraviolet light contributes to rapid rise in temperature by radiation in a space. In fact, nearly, 90-95% of the energy used in non-food display specific fluorescents is wasted in producing infrared radiation and thus, enormous heat (Whitaker, 2005).
Therefore, the temperature in a refrigerated beef display rack can be modulated by utilization of an intelligent lighting design that shall not contribute much to an increase in temperature by radiation in the display rack space. One of the best options lies in the use of specific LED lighting in the display cases. LEDs are comparatively cool with negligible infrared emission and heat detectable only in the base region (Whitaker, 2005).
Promolux offers a range of smart ‘semiconductor food display’ LED lights that extend the shelf life and quality of beef. These LEDs do not have a filament at all (which is the chief source of infrared and ultraviolet radiation in normal fluorescent display lighting), thus, modulating the radiation process in the shelf space and thereby, diminishing the scope for temperature related lipid oxidation and microbial spoilage.
References
- Boyer, Renee, and Julie McKinney. “Food Storage Guidelines for Consumers.” Virginia Cooperative Extension (2009): n. pag. Web. 7 Dec 2009.
- Clodic, D. and Pan, X (2002). “Heat Exchanger Shelves For Better Temperature Control Of Food In Open-Type Display Cases”. International Refrigeration and Air Conditioning Conference. Paper 607. http://docs.lib.purdue.edu/iracc/607.
- Elisabeth Borch, Marie-Louise Kant-Muermans and Ylva Blixta (1996). Bacterial spoilage of meat and cured meat products. International Journal of Food Microbiology. Volume 33, Issue 1, November 1996, Pages 103–120.
- Laguerre O, Hoang M, Alvarez G, Flick D (2011). Influence of room temperature on food safety in refrigerated display cabinet. ICEF11, International Congress on Engineering and Food, May 2011, Greece.
- Marianne Jakobsen and Grete Bertelsen (2000). Colour stability and lipid oxidation of fresh beef. Development of a response surface model for predicting the effects of temperature, storage time, and modified atmosphere composition. Meat Science. Volume 54, Issue 1, January, Pages 49–57.
- Whitaker, T. (2005, May). Fact or Fiction—LEDs don’t produce heat. Retrieved May 14, 2009, from http://www.ledsmagazine.com/features/2/5/8.