Retail Meat Display Lighting

“The retail case life of fresh beef is usually limited to 2 to 3 days due to the development of undesirable surface discoloration. This reduction in color acceptability has been shown to be related to the growth of psychrotrophic bacteria at the meat surface. The retailer can improve the keeping quality of beef by reducing the number of bacteria initially contaminating the meat and by controlling the growth of organisms which are present.”

“In view of the importance of color to beef acceptability, the extent of bacterial-induced surface discoloration can be used as a measure of retail beef case life. As bacteria grow on the meat surface they accelerate the oxidation of meat pigments which results in a progressive deterioration of the acceptable red color and the appearance of varying degrees of brown surface discoloration until the steak is completely discolored.”

“The growth rate of a typical beef spoilage bacteria can double as the temperature of incubation increases from 1 to 5° C and can triple with a further increase to 10° C. Increased bacterial growth means reduced case life.”

“The actual surface temperature of steaks on retail display is much higher than that recorded at the blower thermometer. In this particular case, the blower thermometer indicated a temperature of -0.5° C while displayed steak surface temperatures were on the average about 8° C higher (7.3° C).”

“Another important consideration is the intensity and duration of display illumination. The display case in the studies described herein was illuminated with 150 watt incandescent, cool-beam floodlights to give a light intensity of about 80 foot-candles at the meat surface. Lighting was automatically timed to illuminate the display case for 12 hours/day."

"During this 12 hour period of illumination steak surface temperatures were found to be higher than in the absence of illumination. This is a type of ‘greenhouse effect’ in that the heat produced by radiant energy is absorbed by the meat and trapped between the polyvinyl wrap and the meat surface. Thus, although display illumination enhances the appearance of beef it is detrimental to keeping quality."

"Consumer studies have shown that physical appearance of a retail cut in the display case is the most important factor determining retail selection of meat products."

"Consumers select meat cuts primarily for leanness and then for appearance and freshness, with judgments for the latter two attributes based primarily on brightness of color (ASPC, 1964; Rhodes et al., 1955; Seltzer, 1955). The importance of attractive lean color was further emphasized by Shaw (cited by Nelson, 1964), who reported that 36.7% of the meat purchases from self-service counters were unplanned and that these impulse purchases were made primarily because of attractive appearance."

"Today's consumers are very demanding and quality driven, they have learned through experience that the desirable color of fresh/ground beef is bright cherry-red, and any deviation from what they perceive to be acceptable will not be purchased. Retailers discount or discard cuts that have color characteristics outside the marketable range resulting in economic losses to the company."

"Current estimates are that the value loss of fresh beef due to discoloration costs the retail beef industry 4 to 5 percent of the wholesale price or up to one billion dollars a year (Hoffman-La Roche Inc., 1993). Beef that is perfectly wholesome and safe to eat is discounted or thrown away every day because it has lost its bloom, or cherry red color, and become visually unappealing to consumers (Westcott et al.,1997)."

“The reports of other workers (Danner, 1959; Mize & Stringer, 1959; Marsh, 1958) [found] that colour was the most important selection criterion."

"The fact that 41.9% of the consumers interviewed in the present study considered colour when making meat purchases substantiates that colour is one of the most important selection criteria."

"Meat spoilage is a significant concern for the Canadian beef industry, with related costs estimated at $200 million per year."

"Previous research has shown that lactic acid bacteria are the primary bacteria in vacuum-packaged meat and that with extended refrigerated storage, their numbers attain high levels and spoilage ensues. Currently, vacuum packaging is used to market about 80 percent of Canadian beef to domestic and international markets."

"Consumers view color as one of the most important attributes of fresh beef when making a decision to purchase retail product. Color, therefore, determines appeal of the product in the retail case and consumer acceptability."

"Because visual appearance of ground beef is important to the consumer when making the decision to purchase, retailers discount or discard product that is not acceptable in color, resulting in a substantial economic loss for the retailer."

"When a consumer is presented with a package of fresh meat, visual appearance is rapidly assessed and is interpreted into a response: to buy or not to buy, to eat or not to eat."

"Color is probably the single most important appearance factor, especially today when meat cuts are already packaged."

"Since cold-tolerant bacteria capable of spoiling meat continue to grow to at least -3° C, their growth on unfrozen meat can not be prevented and as the meat temperature increases the growth rate of the bacteria also increases."

"Increasing the storage temperature by only a degree or two has a profound effect on product storage life in any type of preservative packaging utilized. Therefore, any temperature increase, above the optimum, produces a proportional decrease in storage life. For example, storage at commercial (2° C), as opposed to optimum (-1.5° C) temperatures reduces product storage life by 50% (Gill and Shand, 1993)."

"In addition, surveys of retail outlets have shown product surface temperatures to be 4 to 25° C higher than the temperature of the retail case (Holland, 1979), and a product surface temperature of 10° C was not uncommon under retail conditions (Greer, 1984)."