Color preservation in meat and poultry is more about consumer perception than it is about quality and safety. 
The Power of Meat 2018 affirms that the appearance of fresh (uncooked) meat and poultry is how consumers perceive quality. It also happens to be the second biggest influencer of purchase, sandwiched between price per pound and total package cost.

“For many shoppers, price goes hand-in-hand with appearance to solidify the purchase,” says Anne-Marie Roerink, principal of 210 Analytics LLC, San Antonio, Texas, and co-author of the annual study.

Appearance includes everything from package to label to actual food. Case-ready fresh meat and poultry makes it easier for retailers to deliver on appearance. Processors can incorporate moisture-absorbent pads to soak up excessive juices. Modified atmosphere reduces spoilage bacterial growth as well as promotes vibrancy. And, ingredient technology may assist with maintaining desirable color.

When it comes to meat color, shoppers have expectations. Fresh beef should be bright cherry-red, while fresh poultry should have some pink. Often, loss of color does not render the meat spoiled or unsafe to eat. However, in consumers’ eyes, when color expectations are not met, the product is inferior and is passed over for a more appealing option.

Characteristic colors are formed when myoglobin in the meat is exposed to oxygen. This converts the myoglobin (blue) to oxymyoglobin (red). Think how enclosed veins are blue and exposed blood is red. Different species of meat have different concentrations of myoglobin in their blood, which is why there are varying intensities of red in meat. For example, beef has about four times as much myoglobin as pork.

Factors influencing beef and pork color are extensive. They include animal conditions such as age, nutrition and metabolic state, as well as muscle type and pH.

Greying or browning of fresh beef and pork products occurs when the oxymyoglobin gets oxidized and transforms into the harmless, yet unappealing metmyoglobin. Ingredients can assist with preventing this undesirable transformation.

Raw whole-muscle poultry color expectations are different and can be quite varied, from bluish-white to yellow. Color depends on the bird’s age, breed, diet and even slaughter and post-slaughter conditions. Further, the white meat is virtually void of myoglobin while dark meat gets its name because of its myoglobin content.

With ground poultry, color variations are typically due to the amount of white and dark meat in the mixture. In packaged ground chicken or formed uncooked chicken, such as that encountered in patties or kiev-style products, a higher amount of dark meat translates into a darker pink. More white meat or skin in the chicken blend gives it a lighter tone.

Proper color development in certain cooked or smoked meats is just as important as color retention in fresh meat. In pork, for example, nitrogenous compounds such as nitrates and nitrites, which are added to the pork via traditional cures, give ham and bacon a desirable pink color. Select plant and spice extracts are also able to deliver desirable pink color to uncured pork products.

The appearance of ready-to-eat deli-style meats – in the deli as well as packaged – also influences purchase. The most common discoloration is greying, the result of oxymyoglobin oxidation. This may be managed through the addition of antioxidants.

Another common discoloration is known as greening. This has to do with the way light bounces off the surface of the deli meat. It is a phenomenon known as diffraction and may produce an almost rainbow-like iridescent color. Diffraction involves the fibrous strands of protein in the meat and white light, which is composed of a spectrum of different colors of varying wavelengths. After meat is sliced, the cut ends of the tightly packed strands form a series of grooves. When light hits these grooves, some of the light is absorbed and some of it is diffracted. These color waves bend at different angles, producing an iridescent effect.

Diffraction depends on the grooves being structurally intact and perfectly aligned. Therefore, iridescence discoloration is more common on processed deli-style meat, which has a firmer texture than raw meat.

This shimmer is also more noticeable in darker cooked meats, such as roast beef and ham. Turkey and chicken are too pale to showcase the reflected light bends. It also matters if the deli product is restructured or whole muscle. In the latter, the ground and reformed fibrous proteins are no longer aligned and therefore cannot diffract light.

There’s not much a meat processor can do to prevent this shimmering effect. However, how the meat is sliced at the deli counter or before being packaged has an impact. Only cuts that are sliced against the grain, or perpendicular to the direction of the fibrous proteins, show iridescence. Blade sharpness may also influence the development of the grooves that diffract the light waves. Sharper blades produce cleaner cuts with smoother surfaces, which are better for refracting light.

Nitrates and nitrites have traditionally been added to pork via cures. This gives ham and bacon a desirable pink color.

Tools to preserve color

Processors have many varied ingredient technologies to assist with preserving color in fresh and ready-to-eat meat and poultry. Phosphates are a common and highly effective option. They are most often used in meat processing to improve juiciness, tenderness and cook yields, but they may also impact color development and maintenance in both fresh enhanced and processed cured and non-cured meat products.

There are many phosphates to choose from, all with their unique claims to fame in meat and poultry processing. Depending on the desired effect, they are either used alone or in application-specific blends for the best impact on the finished product.

A&B Ingredients Inc., Fairfield, New Jersey, is exploring how a dilution of a new lauric arginate formulation improves bright color retention in fresh meat and poultry. Derived from natural compounds, lauric arginate has no flavor impact and is effective at very low usage rates.

“We recently conducted a study to explore the benefits of using a lauric arginate solution as a treatment for raw meat products, which goes beyond the category of ready-to-eat meats where it is currently used,” says Gil Bakal, managing director. “It is a low-cost option for processors, and in many cases, requires no label as lauric arginate is permitted in raw meat products as a processing aid up to 200 ppm.

“Some customers have reported seeing a benefit in ground beef applications after spraying the beef trim,” he says.

There are also several plant extracts that have been shown to ensure appealing color. Rosemary and green tea extracts, for example, are proven ingredients for their ability to positively impact the appearance, taste and quality of meat and poultry. Both contain phenolic compounds that function as antioxidants, preventing oxidative breakdown of meat pigments by being oxidized themselves.

The main difference between the two plant extracts is that green tea extract has a lower negative flavor contribution to the final product. Thus, using a lower level of rosemary extract in combination with green tea extract allows the manufacturer to increase the natural plant extract usage rate, often resulting in a blend that works better in the meat product than using rosemary alone, according to a study conducted at the Univ. of Nebraska-Lincoln for Kemin Food Technologies, Des Moines, Iowa. Kemin now offers domestically grown organic rosemary.

When slicing cooked roast beef, cutting with the grain prevents the undesirable iridescent coloring effect. 
Acerola cherry extract is also proving to be a highly effective ingredient in meat and poultry. Extracted from the namesake wild plant grown in tropical and subtropical regions, acerola extract contributes the antioxidant vitamin C.

“Our acerola extract blends delay both lipid and myoglobin oxidation, thereby delaying the onset of color loss and maintaining the desirable color and quality of meat products,” says Courtney Schwartz, senior marketing communications manager at Kemin. “When used in combination with rosemary and green tea extracts, acerola is more effective at delaying early discoloration than either extract alone.”

Corbion, Lenexa, Kansas, recently introduced an advanced food safety ingredient that also assists with color retention in fresh sausages and ground meats. It is based on a patent-pending blend of vinegar and jasmine tea extract. Vinegar is a source of acetic acid that is very effective against spoilage organisms and pathogens and is commonly used in natural and clean-label processed meats. However, vinegar can affect the pH of meat products, which can be detrimental to color and bind. The pH of this ingredient has been optimized to maintain color uniformity and reduce grey discoloration during shelf life.

Through a partnership with Prosur Ingredients of Spain, Wenda Ingredients, Naperville, Illinois, offers a range of proprietary blends of fruit and spice extracts with proven antimicrobial and antioxidant properties.

“One solution is designed for fresh meat and poultry and has been shown to improve shelf life by preventing oxidation discoloration and growth of spoilage microorganisms,” says Chad Boeckman, national accounts and marketing manager at Wenda Ingredients. “On fresh, conventionally packaged chicken breast, shelf life can often be doubled from 12 to 24 days.”

Another ingredient option contributes desirable cured color and flavor to true-uncured cooked meats, such as deli-style hams, bacon and pepperoni. “This system allows for cured color with the lowest possible amount of residual nitrates or nitrites in the industry,” Boeckman says.

In addition to plant extracts, ingredients made from real fruits and vegetables high in antioxidants may assist with preserving coloring. They often exert additional benefits.

Basic American Foods, Walnut Creek, California, for example, offers a multi-functional ingredient made from dried potatoes, with or without dried mustard, which is how it is declared on ingredient statements. In addition to helping retain red color in fresh meat products, the ingredients bind water, thus increasing yield; enhance freeze/thaw stability; and reduced lipid oxidation. 

“Dried potatoes are a concentrated source of antioxidants,” says Daniela Sanfelice Boyd, director of ingredient sales. “As an ingredient in meat products, dried potatoes support clean-label initiatives. They are minimally processed, non-GMO and gluten-free.”  

When 2 percent of the ingredient was blended into fresh (uncooked) beef patties, the patties showed improved color compared to the control (beef only) after four days of refrigerated retail display, according to a study conducted at the Univ. of Idaho Meat Science Research Lab, Moscow, Idaho. The version with mustard, where the mustard acts as a mild flavor enhancer while also delivering additional antioxidants, provided even more resistance to discoloration. 

“Both dried potato ingredients produced juicier, more acceptable patties than the control and the patties made with texturized vegetable protein (TVP),” Boyd says. “The dried potatoes also reduced lipid oxidation in fresh patties during refrigerated storage and in cooked patties during frozen storage.

“Although preserving color is not a priority in fully cooked breaded chicken products, meat processors find that adding 2 percent of our dried potato ingredients to the ground chicken mass increases yield, maintains firmness and slows lipid oxidation, all without the addition of phosphates,” Boyd says. “Both dried potato ingredients produced a product with increased consumer acceptance to the control (no additives).”  

Plum ingredients are another option. Dried plums have been shown to assist with color in fresh and cooked meat products. Not only are they a source of antioxidants, they contribute to a desirable red hue. Thus, they can be used to enhance color, often in conjunction with other ingredients.

There’s a trend with incorporating finely diced or chopped mushrooms into ground meat matrices to make lower-fat, flavorful burgers, meatballs and other meat dishes. Though the mushrooms have not been shown to exert any antioxidant coloring-preservative effect, they do contribute a desirable brown color to both fresh and cooked ground meat products. Thus, they provide another way to improve the appearance of meat and poultry.

Color is an important visual cue for consumers when they are shopping for meat and poultry. Desirable color suggests freshness, quality and taste. It’s the way to get product into the cart and onto the dining table.