When meat is marinated, the theory is that it holds more moisture in the spaces between its protein filaments. Salt increases the space in between the filaments by extracting salt-soluble meat proteins and causing the myofibular proteins to unfold so there is more space to trap the moisture. Phosphates increase meat pH, which shifts the pH away from the meat protein’s isoelectric point and increases the water-holding capacity.
“Xanthan is the gum of choice in both marinade dry mixes and ready-to-use liquid marinades due to its salt and pH tolerance,” adds Nieto. “Gums perform various functions in marinades, including providing a sauce-like appearance. A soupy or watery marinade reduces the shelf appeal of these products and is perceived as a defect. Gums also suspend spices and insoluble particulates; at the same time they thicken and improve cling of the sauce or marinade to the meat.”
The surface marinades used in case-ready meat products are very different than the ones consumers purchase in a bottle and apply at home, notes Chris Kelly, director of technical services, Advanced Food Systems, Inc., Somerset, NJ. “We’re talking having the uncooked protein sit in the marinade for about three weeks at refrigerated temperatures,” he says. “The bottled marinades are designed to do their trick sometimes in 30 minutes.”
Kelly explains that such industrial marinades cannot be too acidic, because the acid will degrade the texture of the protein over time. “So, instead of using acidic ingredients such as vinegar or various citrus juices, we will often formulate such marinades with the flavors of these acids instead of the actual acid.”
Marinades for refrigerated, uncooked protein products should be customized for each application. “There are many variables to consider, including the protein type, the cut, the package type, the gas flush and the desired shelf life,” says Kelly. “And, of course, what’s really important is creating that signature flavor profile that keeps consumers buying your product.”
From an economic standpoint, it makes sense for meat and poultry packers to purchase marinade mixes that are put into solution at the plant. These mixes could be dry blends or concentrated slurries that are reconstituted with water.
“Water quality must be factored into consideration,” says Bosch. “Hard water reduces the solubility of many ingredients in marinades. Other contaminants in water also affect product quality. For example, nitrites, even at very low levels, can cause discoloration in meat. Metals, such as iron and copper, as well as chlorine in water, will accelerate meat oxidation.” He notes some phosphate blends are customized to work with water high in minerals and metals.
Injection and vacuum tumbling are the two most-common techniques to introduce marinades to meat and poultry. Injection is typically used on larger cuts or whole-muscle products that are bone-in, while tumbling works best on smaller cuts when there is a high surface-area-to-volume ratio. The latter allows for thorough penetration of the marinade for consistent flavor through the product. Further, when tumbling, vacuum is critical as it assists in tenderizing the protein by expanding the muscle and breaking down some of the structured network, improving absorption of the marinade.
Making marinades
Marinades for case-ready proteins, notes Kelly, need low levels of soluble solids, such as salt, sugar and maltodextrin. “If they are too highly concentrated, depending on the application,” he says, “they could pull moisture out of the protein. And one of the reasons marinades are added to protein is to keep them tender and moist.”
Keeping solids concentrations down in a marinade is important, notes Jenny Zhou, food scientist, ICL Performance Products LP, St. Louis, “because the solids will build up on the surface of the protein and form a barrier, preventing the protein from absorbing the flavorful ingredients.
“Many marinades include phosphates,” continues Zhou, “typically alkaline phosphates, which increase the meat water-holding capacity by increasing the protein pH away from its isoelectric point. The finished products are tender and juicier after cooking or reheating.” Enhanced moisture retention also means the consumer sees less purge so the packaged product looks more desirable.