|Ultraviolet Light in Fresh Beef Display Cases
Early studies found that beef stored in the dark over a period of three to ten days did not change color significantly, while beef stored under fluorescent lighting for the same amount of time began to turn brown after only 5 days.
In a 28 day study conducted at the University of Zaragoza in 2000, ultraviolet light was shown to have a profound effect on the rate of beef spoilage and the creation of metmyoglobin, the pigment that gives meat a brownish surface color. All fresh beef in this study were packaged in a modified atmosphere of 70% oxygen, 20% carbon dioxide, and 10% nitrogen.
Beef displayed under PROMOLUX lamps and regular fluorescent lights with a PROMOLUX filter, which both block UV radiation, maintained virtually the same bright red color, fresh smell, low bacterial count, and low levels of metmyoglobin as beef stored in the dark, while beef displayed under a standard supermarket fluorescent light became brown and decomposed rapidly after only 12 days.
After 17 days, meat under regular supermarket lighting had much larger percentages of surface metmyoglobin, higher levels of psychrotrophic bacteria, and poorer odour quality than the beef displayed under PROMOLUX lights or PROMOLUX filters, or beef kept in darkness.
This study proved that ultraviolet light as emitted by standard retail fluorescent lamps accelerates bacteria growth, the brown discoloration of beef caused by high concentrations of metmyoglobin, and lipid oxidation which leads to rancidity.
PROMOLUX True Color Definition Lamps and LEDs
PROMOLUX balanced spectrum fluorescent lamps and LEDs emit lower levels of heat and ultraviolet radiation than regular grocery store fluorescent lamps, thus reducing the rate of meat decomposition. Compared to other fluorescent lighting, PROMOLUX lamps emit 86% lower UV B radiation, a shorter wavelength that penetrates and causes heating, and 52% lower UV A radiation, a longer wavelength that tends to affect surfaces.
PROMOLUX lamps and LEDs are designed for true color definition, they have a more balanced visible spectrum than other fluorescent lamps. The yellow and green wavelengths that are predominant in regular fluorescent lighting are the most damaging wavelengths in the visible spectrum. PROMOLUX lamps emit a more balanced range of wavelengths, including more of the red and blue wavelengths and more moderate levels of the yellow and green wavelengths.
This balance ensures that beef maintains its cherry red bloom while its fat and marbling are displayed in their true colors, rather than appearing brownish with yellowed or pink fat which often is the case with regular meat display lighting.
FRESH BEEF DISPLAYS IN RETAIL SUPERMARKETS
The National Cattlemen’s Beef Association and other groups estimate that up to $1 billion in beef are wasted each year in the United States, a loss of four to five percent of the wholesale price, while in Canada it is estimated that $200 million are lost each year as a result of beef spoilage in supermarket meat departments. <more...>
FRESH BEEF COLOR
Various studies have found that consumers consider color to be the most important factor when judging the freshness and acceptability of beef: they prefer beef cuts that are bright red. <more...>
BACTERIA AND FRESH BEEF DISPLAYS
Bacteria contribute to the discoloration and spoilage of beef by accelerating the oxidation of myoglobin to metmyoglobin, the pigment that causes fresh meat to look brown. <more...>
TEMPERATURE, LIGHTING, AND FRESH BEEF DISPLAYS
Average steak surface temperatures are 8 to 10°C higher than the temperature recorded on the display case thermometer, sometimes fluctuating to 20°C higher particularly when the meat was exposed to meat display case lighting. At higher temperatures, bacteria grows exponentially. <more...>