acts to remove excess water, creating a firmer texture and, in some cases, a rind (Guinee and Fox, 2004). Salt also contributes to characteristics such as meltability, shredding, stretching, and flow (Reddy and Marth, 1991).
Other sodium-containing compounds are also used to establish physical properties of food products. Some of the more common sodium-containing compounds are used in baked goods (e.g., sodium bicarbonate, also known as baking soda) for leavening and to condition dough for easier processing. For a variety of products, such as sauces and dressings, emulsification and thickening agents may contain sodium. Examples of sodium-containing compounds that impact the physical properties of foods, along with their functions, are provided in Box 4-1.
The practice of enhancing raw poultry, beef, pork (Baublits et al., 2006; Brashear et al., 2002), and seafood products (Rattanasatheirn et al., 2008; Thorarinsdottir et al., 2004) with solutions that contain sodium is also worth noting. Typically, these enhancement solutions include salt and sodium phosphates. One reason for the use of this processing technique is to improve the tenderness (which consumers may perceive as juiciness) of leaner cuts of meat. Such cuts of meat can become tough due to their low fat content, which, in the case of beef and pork, is a result of genetic advances made to produce leaner animals (Detienne and Wicker, 1999). Increasing product yield may be another driver for the use of this technique (Detienne and Wicker, 1999). Clearly, salt and sodium phosphates increase the sodium content of the overall product. For example, a regular serving of meat (114 g, reference amount commonly consumed) without enhancement contains 68 mg of sodium, but that same serving of meat injected up to 10 percent of its weight with brine containing 4.5 percent sodium tripolyphosphate and 3.6 percent salt results in 384 mg sodium per serving (DeWitt, 2007).
The difficulty of reducing sodium without losing desirable physical properties is dependent on the specific food application and the availability of other ingredients that can fulfill similar functions. In some foods (e.g., certain cheeses and processed meats), the salt used to create special physical properties may be impossible to remove, given current technologies. As previously mentioned in the discussion of challenges to reduce sodium while maintaining food safety, reformulation has a number of costs that are described further in Chapter 6.
Still, for many products, more salt may be added than is truly needed for the desired physical property. In these cases, research to determine critical salt levels may be necessary to quantify the amount of salt that can be