The technology could also help to prevent the discolouration of beef, which can affects consumers’ perceptions of the meat’s shelf-life.
The project, undertaken by Kansas State University compared LED lighting in units to fluorescent lights, which are widely used in refrigeration units across the industry. It looked at the effects on several specific types and cuts of meat, including pork loin steaks, beef loin steaks, beef inside round steak (a unique cut from the semimembranosus muscle), minced beef and minced turkey. As well as colour differences, which can affect consumers’ perceptions of shelf-life, the team looked at the oxidation process of fresh meat, which can affect the rancidity and taste, under both types of light to see if there was a difference, and the internal temperature of the meat.
LED lighting was found to keep the internal temperature of the beef cuts lower and the team also calculated that the operational efficiency of the LED-lit units was greater. This was measured by recording the number of cycles each cooling condensor performed, along with the running time (per hour) needed to keep each display case cool. An average cycle per running hour was calculated to compare the two.
The team also found that the LED lighting helped to lessen the discolouration of beef cuts. Researcher Kyle Steele explained that expert visual colour panellists detected less discolouration under LED lighting than the fluorescent lighting systems, although there was no significant visual difference in discolouration on either the pork or ground turkey.
Steele told GlobalMeatNews: “Instrumental colour revealed a true difference in discolouration for the beef inside round steak, with steaks under LED lighting having better colour stability.
“The shelf-life of the meat products was determined by visual colour panellists’ scores. So when their scores reached a level where they would no longer purchase the product at full price, due to discolouration, then that product had reached its shelf-life.
“However, the results for the lipid oxidation were the opposite of what we had predicted. Even though the cooler and product temperatures were lower for products in the LED case, pork loin chops, ground turkey, and the inside round steak under LED lighting experienced greater oxidation, as measured by the TBARS (thiobarbituric acid reactive substances) method.
“However, the levels of rancidity had not reached the detectable threshold level perceived by consumers. In other words, the colour life of the product had reached its limit before the oxidation reached its limit.”
The research was supported by Cargill Meat Solutions and refrigeration manufacturer Hussmann Corp.