KANSAS CITY — Yield enhancement refers to the binding of moisture – natural juices or added water – in meat and poultry to increase the weight of the product, and thus saleable volume. However, as with many technologies, ingredients used for yield enhancement often provide extra benefits.
The primary bonus is extra moisture translating to a juicier, more succulent protein. Some ingredients assist with color retention while others retard lipid oxidation. Still others provide food safety benefits. Yield improvement ingredients may also reduce drip loss, limit package purge and decrease freeze-thaw drying.
The role of pH
The pH of meat and poultry is a key factor in moisture retention. The higher the pH, the greater the protein’s ability to bind moisture. Processing must also be considered.
“The pH of a live animal is 7, after rigor it can drop as low as 5.4, so the goal is to manipulate it up again to more than 6,” said Dave Grex, director of meat technology for Chicago-based Newly Weds Foods.
This may be accomplished through the addition of functional ingredients, as well as environmental considerations.
“It’s important to test your water for pH, minerals and impurities, and adjust, soften and filter as needed,” Mr. Grex said. “Always keep in mind that the animal has up to 70% water already in the muscle, so it makes sense to bind as much of that as possible.”
Newly Weds Foods carries a full line of sodium and potassium phosphates for more traditional means of function, as well as specialty clean label ingredients, including organic acids, citrus fibers and flours, and oat hydrocolloids.
“All of these are highly functioning and work by either trapping the moisture inside the meat, or manipulating the pH to increase the protein water holding capacity,” Mr. Grex said.
Each of the processes involved in turning muscle into a consumable protein can impact yield. This includes cutting, chopping, grinding, emulsification, refrigeration, cooking, freezing, thawing, packaging and reheating, according to Ron Jenkins, commercial development manager of meat, poultry and seafood for Innophos, Inc., Cranbury, N.J. To maximize yields, functional ingredients are added to handle the stresses resulting from such processing and handling treatments.
“Many precooked meats can experience cook shrinks of 30% or greater," said Tom Katen, technical service representative for Cargill Texturizing Solutions. "Plus, they can have a very dry texture when reheated. By adding functional ingredients, you get better yields, freeze-thaw benefits and a great-tasting precooked meat item.”
Ready-to-eat deli meats also often contain ingredients to improve cook yield.
“The improved cook yield results in more saleable volume, more consistency, reduced purge in package and better margins for the processor,” said Stephanie Carlson, global marketing communications manager of the meat industry for Corbion, Lenexa, Kansas. “The benefit for the consumer is a juicier product, improved texture and an overall better quality product.”
Varying by application
Functional ingredients include starches, fibers, phosphates and even fruit extracts. These ingredients use different mechanisms to increase yield.
“These mechanisms differ depending on the type of water binding (physical or chemical), the conditions needed to activate the functional ingredient (e.g., temperature, pH), composition and particle size,” said Brock Lundberg, president of research and development for Fiberstar. “Because these functional ingredients provide unique functional benefits, it is common to see blends used to improve yields in specific meat processes.”
With whole muscle proteins, yield enhancement ingredients are typically added via injected or tumbled marinade. For ground and comminuted systems, they may be blended into the product in a dry or liquid solution format.
Historically, phosphate salts have been one of the most common ingredients for yield enhancement in meat and poultry products, as they efficiently increase pH. This maximizes water-binding potential of the proteins.
“Phosphates are also very useful with providing muscle-to-muscle binding,” Mr. Jenkins said. “This is critical in boneless hams and whole muscle deli products. They can establish and stabilize meat batter emulsions, which is necessary to maximize yields and deliver the desired texture.”
While phosphates improve yield, they also protect color and flavor by protecting the fat from oxidation by the metal ions inherent in meat, water and other ingredients. This protective function continues during processing, frozen storage and subsequent cooking and reheating, according to Mr. Jenkins.
Innophos offers a full line of specialty phosphates and phosphate blends that include sodium and potassium forms, both individually and in combination. Selection is based on the target application, process conditions, water quality and other ingredient characteristics.
“For example, di- and tripolyphosphates will facilitate hydration and binding of whole muscle chicken proteins through a myriad of processes including cooking, storage, freezing, batter and breading, and subsequent reheating,” Mr. Jenkins said. “Additionally, the phosphates will protect the fat component from oxidation thus providing clean flavor regardless of repeated heating applications.”
Another familiar yield enhancement ingredient is textured soy protein, which can hold up to six times its weight in water. Two of the most common soy meat extenders, textured soy flour and textured soy concentrate, are often confused.
“Textured soy flour includes the sugars and dietary fiber naturally contained in the soybean, while textured soy concentrate does not,” Mr. Katen said. “That distinction has little effect on the functionality or appearance of the two products. The big difference is in the cost. Textured soy flour is usually half the cost of concentrate. Regardless of the textured soy protein option used, it’s important to match the right size, shape and color to the meat application."
Minced pieces work best in applications such as chili, pizza toppings and taco fillings, where particle definition is important. Flaked particles are best for products such as patties, nuggets and Salisbury steak. The determining factor is how the product is cooked. Flakes hydrate faster in cold water, but are torn apart in high heat or long cooking processes. Minced forms require longer hydration and are typically used in retort, high-heat applications.
In kettle-cooked products such as chili, textured soy protein can absorb the melted fat, improving product appearance and customer appeal. At the same time it is absorbing fat, it’s adding protein, increasing the protein-to-fat ratio in a prepared meat product.
Starches and fibers derived from plants are increasingly being used to plump up meat and poultry products. For example, The Dow Chemical Co., Philadelphia, offers cellulose ingredients that may be used in various comminuted meat applications.
“Addition provides a good, juicy bite, even in reduced-fat products,” said Christopher Spontelli, marketing manager for Dow. “In hot dogs, 0.75- to 1% modified cellulose can be used to replace lean meat and reduce cost. Our data has shown a yielded cost savings of 4- to 6% over control, while still maintaining heated firmness and juiciness.”
Some yield enhancement ingredients allow for fat reduction in fried foods. For example, when modified cellulose is used in the coating system of fried meat products, fat uptake can be reduced as much as 35% during the frying process. These fibers can also increase yield in fried foods by increasing moisture retention during frying and extending hold time under heat lamps, as well as improve adhesion of coatings to the meat substrate.
“When it comes to clean label formulating, the functional ingredient formulation tool box shrinks,” Mr. Lundberg said. “Processors are tasked to replace their workhorse functional ingredients with clean label versions, while maintaining yields, reduced purge and comparable sensory results.
“One newer functional ingredient that is up to the challenge is citrus fiber. It can be used along with clean label starches, such as native rice starch, to maintain yields when replacing chemical phosphates.”
Not all citrus fibers are created the same, Mr. Lundberg said.
“Our citrus fiber is a very unique clean label functional fiber that is classified as a binder and can be used at levels up to 3% in meat and poultry products, with labeling options of ‘citrus flour’ or ‘dried citrus pulp.’”
When used at less than 1%, this citrus fiber has been shown to reduce purge by up to 4% and increase yields by as much as 5%. These functions are attributed to the citrus fiber’s composition, which is about 70% dietary fiber (soluble and insoluble) and protein content (about 8%). This is in addition to the cell wall structure that provides water-holding stability, a structuring effect and emulsification properties.
Corbion offers a patent-pending blend of citrus fiber and vinegar powder that not only improves cook yield, it provides food safety benefits. Declared simply as “citrus fiber, vinegar,” it is considered a clean label option for all-natural marketed products.
“Data show a 4.4% yield increase in natural turkey breast when this ingredient is 1.5% of a marinade,” Mr. Carlson said. “In an injected natural ham with fibrous casing, a use level of 1.2% allowed for a 9.9% yield increase over the control.”
“We offer rice starch that binds moisture, assisting with maintaining yields and margins without any negative impact on the end product," said Olivier Chevalier, business development manager for meat applications at Belgium-based Beneo. "Being pure white, rice starch ensures that poultry, in particular, has a clean look, with no pinking.”
Sampling tests by Texas A&M Univ. showed rice starch improves yields comparable to modified corn starch, the most common starch used in tumbling of poultry products in the United States. Additionally, a sensorial test with 50 volunteers confirmed that in terms of organoleptic properties, rice starch is a viable alternative. There were no differences in taste, tenderness, juiciness and appearance between the starch solutions tested.
Unlike some other hydrocolloids, rice starch does not increase a marinade’s viscosity. Due to the structure of amylopectin and its ratio to amylose in rice starch, there is very low retrogradation, enabling water retention to be maintained after the poultry has been packed.
“This not only means that there is no unsightly water release in the packaging for consumers, but that the product remains moister for the duration of its shelf life,” Mr. Chevalier said.
Ingredion Inc., offers functional native starches for clean label chicken products. Studies show that native starches may effectively replace modified starches and sodium tripolyphosphate to lock in both moisture and flavor in poultry products.
Fruit-derived ingredients offer a label-friendly yield enhancing option. For example, the chemical composition of plums makes them powerful water binders in many types of meat and poultry.
“We offer fresh plum concentrate and dried plum powder and puree for yield enhancement,” said Rick Perez, research and development chef and spokesman for Sunsweet Growers Inc. “These products contain naturally high levels of sorbitol (about 15%) and fiber. Sorbitol attracts moisture while fiber absorbs moisture and holds it in place.”
Plum ingredients are naturally high in antioxidants, which may enhance shelf life of both raw and cooked products and have been shown to lower the incidence of warmed-over flavor. At the same time, for many applications, the rich deep brown color of dried plum product can replace the need for caramel coloring.
“Our plum ingredients are approved as binders and allowed at levels of up to 2% of the total product formulation when used solely for moisture binding,” Mr. Perez said. “This limit does not apply when the ingredients are used as a flavor component, such as when added to sausages to improve taste and texture as well as yield.”
With plum ingredients, less can be more. A study done by the Univ. of Arkansas at Fayetteville using boneless skinless chicken breasts found that adding more plum product did not necessarily lead to more marinade pick-up. The study showed that a marinade with 1.1% fresh plum concentrate had a 10% marinade pickup while a marinade with 2.2% of the plum concentrate only had 8%.
“When working with plum ingredients, we recommend lowering total salt and spices to keep flavors in balance,” Mr. Perez said. “These ingredients are flavor extenders, so we recommend decreasing salt content by 10% as a starting point when formulating.”