The Effects of Moisture on Meat

When purchasing prepackaged meat at the grocery store, consumers might find statements related to the product’s moisture content on the label. While some companies add water to meat and poultry products, meat naturally has high moisture levels. As with other food products, moisture content plays a large role in the quality, taste and safety of meat and poultry, making humidity control for meat products an essential part of the packaging process.

Meat and Moisture

Meat, including poultry, is muscle tissue. According to the U.S. Department of Agriculture, this tissue is about 75 percent water and 20 percent protein. The remaining 5 percent is a combination of minerals, carbohydrates, and fats. The actual percentage of moisture in meat depends on the type of muscle, livestock, time of year, and pH. In general, leaner meats contain more water. The reason for this is due to the fact that water is essential for protein synthesis, a process that builds muscle.

In the supermarket, consumers may find enhanced or value-added meat and poultry products that add flavor or make them tender. Processing facilities add the flavor by injecting, soaking, or marinating the meat. A product’s label must indicate the amount of added moisture by stating something like, “…flavored with up to X% of a solution.” Marinated meats refer to meats containing 10 percent or less of a solution. Boneless poultry must not contain more than 8 percent of a solution. Bone-in poultry must not contain more than 3 percent of a solution.

Humidity Control for Meat Products

Implications of Freezing and Chilling Meat and Poultry

When a food processing facility freezes meat and poultry, the water within it turns into solid ice crystals. At the same time, the water expands, causing the sharp edges of the water crystals to tear into the surrounding tissues and ruptures cells.

As meat and poultry freeze, the water in the outermost tissue membranes freezes first, drawing out more water from within the membranes. For this reason, frozen and thawed meat products have less moisture than fresh products. Some food processing facilities use flash-freezing processes to freeze meat because the water forms smaller ice crystals, which do less damage.

When a food label indicates that a meat or poultry product has a certain percentage of “retained water,” it refers to the amount of moisture that it retained from post-evisceration processing, when a producer quickly chills meat using cold water to bring it to a safe temperature. 

While transporting raw meat and poultry between slaughtering and processing facilities, refrigerated trucks are as cold as 1°F. This causes meat to become hard-chilled or semi-frozen. Many processing facilities produce ground beef and poultry in this semi-frozen state. The ice crystals that form in the ground meat make it seem as if it contains more water.

When a supermarket stocks meat and poultry in refrigerated cases that are as cold as 26°F, the frozen cells loosen as the moisture melts. The result of this moisture loss is the visible juice found in a product’s packaging, as meat does not technically bleed. The longer meat and poultry sit in a refrigerator, the more moisture the muscles loose.

Meat and Poultry Packaging

In an effort to preserve the moisture content within meat and poultry products, food processors may vacuum-pack the items. In addition to making the packaging leak-proof and airtight, the vacuum remains in effect while a meat product sits in a refrigerated case. Instead of the moisture evaporating into the air, the juice accumulates in the packaging.

Humidity control for meat products is crucial for preserving their quality. At the same time, humidity control is vital for the food processing, transportation, and storage stages to ensure the delivery of safe products to consumers. Because processing meat and poultry involve significant amounts of water, it is vital that a facility have the ability to control relative humidity levels to prevent the growth and spread of mold, bacteria, and other contaminants without taxing the HVAC system. The custom environmental control solutions from Polygon do just this while increasing productivity, saving energy, and promoting healthy, sanitary conditions. Get in touch with Polygon today to learn more and obtain a free estimate. 

[Photo from Stuart Webster via CC License 2.0]