PROCESSOR’S CHALLENGES IN ADDRESSING NEW MARKET/CONSUMER DEMANDS An Overview of Functional Non-Meat Ingredients in Meat Processing: The Current Toolbox Joseph G. Sebranek INTRODUCTION ing the use of these “toolbox” ingredients is not only the critical nature of the roles they play but also because these My “assignment” as part of this discussion of the chal- are all multifunctional ingredients. Because they impact lenges facing meat processors trying to meet consumer several important properties of processed meats, attempt- demands for clean labels is to review the critical func- ing to reduce or eliminate these ingredients has implica- tional roles of the fundamental non-meat ingredients that tions for multiple changes in the product. are essential for processed meats. The market pressure for shorter, simpler, easier-to-understand ingredient state- WATER ments is providing considerable motivation for processors to reduce or even eliminate some of the traditional, well- One of the functional non-meat ingredients in the current established non-meat ingredients. However, the practical toolbox that is often overlooked is water. While water applications of many of the traditional non-meat ingredi- is a major component of lean meat, it is also commonly ents have been developed and refined as a result of years, added to many processed meat products, and, as such, decades or even centuries of use, and have clearly evolved becomes a non-meat ingredient. Water plays an impor- to play very critical roles in processed meats. These ingre- tant functional role in processed meats which is likely to dients comprise the “current toolbox” that provides the be modified if other ingredients are changed. fundamental means to produce unique and distinctive Water is both simple and unusual compared to other processed meat products of various types. Raw, partial- chemical compounds, in ways that make water highly ly cooked, fully cooked, ready-to-eat, fermented, dried, functional in meat products (Ruan and Chen, 1998; LeM- injected, marinated and dry-cured products all derive este et al., 2006). It is simple in its composition of two distinctive properties from use of non-meat ingredients. hydrogen atoms and one oxygen atom but unusual in its Further, most of the non-meat ingredients in the current ability to form hydrogen bonds between water molecules, toolbox are used almost universally in processed meats and to bond with meat proteins. The significance of the despite the wide variety of products that are produced. hydrogen bonding is that this allows water molecules to These ingredients are analogous to the hammers, saws and be “held” together within meat structures and provides tape measure in a carpenter’s toolbox or the screwdriv- binding of water molecules to polar sites in meat, most ers, pliers and wrenches in a mechanic’s toolbox. Con- notably the myofibrillar proteins. The polar properties of sequently, because these basic toolbox ingredients play water also result in its function as a “universal solvent” critical roles in processed meats, it is important to remem- which, in meat, makes it a highly effective solvent, carrier ber and understand the importance of these ingredients and dispersing agent for salt, sugar, curing agents, phos- before changes are made. Change in the use of the basic phates and other ingredients included in processed meats. functional non-meat ingredients is virtually guaranteed to The solvent properties of water are also necessary for meat require an alternative ingredient or multiple ingredients, protein extraction which is critical to formation of emul- and/or process adjustments to achieve the same or similar sions, binding of restructured products and cooked prod- finished product properties. Part of the problem of chang- uct texture. Added water in the range of at least 10-20% provides improved protein solubility and often more is used. Joseph G. Sebranek, Ph.D. Water becomes an important consideration for the Iowa State University brine strength in a given processed meat product because 215 Meat Laboratory the brine strength is a major factor determining not only Ames, IA 50011 protein extraction, but also bacterial inhibition and prod- [email protected] uct shelf life. The brine strength (salt content in the water % salt phase or % salt + % water) is dependent on both salt and water 42 68th Annual Reciprocal Meat Conference content so obviously any change in either component will tional Salt Reduction Initiative of 2010 www.nyc.gov/html/ alter the effectiveness of the combination. Finally, the doh/html/diseases/salt.shtml, there have been serious ef- available water (AW) is the determining factor for bacterial forts to reduce sodium content of foods in general includ- growth especially in dry and semi-dry processed meats ing processed meats (Choi et al., 2014). It has become and reflects the water that is biologically available from clear that while sodium (and consequently salt) can be re- the combination of water with various other ingredients duced in processed meats to some extent, it appears to be in a product that may bind and restrict water availability virtually impossible to eliminate salt from processed meat (Jay et al., 2005). formulations and still retain expected product properties. Because water has a major functional and quality im- As noted earlier, salt provides an important means of pact on processed meats, there are numerous regulations reducing available water (AW) in processed meats to re- controlling the addition and/or final water content of pro- duce microbial growth and spoilage. With all else equal, cessed meats. However, most of these regulations are fo- reducing the salt content of cooked processed meats will cused primarily on product identity and standardization reduce the shelf life of the product and may introduce rather than issues of safety or quality (Anon., 2005). greater risk of pathogenic bacterial growth as well. Even though water is a highly functional ingredient, it Chloride ions in a cured meat product may also play can also introduce some problems if not monitored care- a small but potentially significant role in cured color de- fully. Hard water can be a source of contaminants that velopment because chloride can accelerate the conver- are detrimental to color and flavor of processed meats. sion of nitrite to nitric oxide during the cure development Even softened water can change if treatment systems are phase prior to cooking (Sebranek and Fox, 1991; Møller changed, so periodic testing is recommended. Plumbing and Skibsted, 2002). Salt is classified as a GRAS (Gener- issues within a plant can result in water contaminated with ally Recognized as Safe) substance and has been consid- bacteria or chemicals providing another good reason for ered to be self-limiting because excessive amounts greatly periodic testing of the water to be used as an ingredient. impact palatability. However, one of the ideas that was suggested during the recent discussions of salt reduction SALT (SODIUM CHLORIDE) in food was that perhaps the GRAS status of salt should be reconsidered (Henney et al., 2010). While such a change Salt (sodium chloride) is clearly one of the most impor- is highly unlikely, the implications of such a change would tant functional non-meat ingredients in processed meats, be immense. and probably the most common in terms of both quantity and frequency of use. The importance of salt is widely CURING AGENTS recognized due to the multifunction role of this ingredi- ent in processed meats, some of which are indispensable. Another absolutely essential tool in the processed meat Because salt dissociates into sodium and chloride ions in toolbox is the curing agents (nitrate and nitrite). Nitrate, the water phase of meat mixtures, its functions are largely of course, is relatively rare in the popular, high-volume the result of the dissociated ions. The ionic strength of the cured meats like frankfurters, hams and bacon because salt-water phase, for example, is necessary for the solubi- it must be converted to nitrite before it becomes effec- lization and extraction of the myofibrillar proteins which tive as a curing agent. In fact, nitrate has been described are responsible for stabilizing fat in emulsion products, as “useless and superfluous” in products cooked within a binding of muscle pieces in restructured products and few hours of formulation (Honikel, 2004; 2010). On the product textual properties that result from heat-set gela- other hand, nitrate is an important ingredient for many tion of the proteins. An ionic strength of 0.5 or greater dry-curing processes where it is reduced to nitrite by bac- is needed for muscle myofibrils to swell and solubilize teria (Leroy et al., 2006), and thus provides a reservoir of myofibrillar proteins (Hamm, 1986). A salt concentra- nitrite during the extended curing and or drying phases tion of about 2% or more will achieve the necessary ionic of dry-cured hams and dry sausage. More recently, the strength under normal circumstances. Cooked product nitrate included in concentrated vegetable products such yields can be expected to decline rather sharply when salt as celery and Swiss chard has been utilized as a means is reduced to less than 2% (Wierbicki et al., 1976; Ruu- of providing curing agents for processed meats labeled as sunen and Poulanne, 2005). “natural” or “organic.” While chloride ions provide much of the functionality Because nitrite is the true curing agent that creates of salt for water binding and yields, it is the sodium ion cured meat properties by reacting with a variety of meat that provides the flavor expected of products with added components, it can be considered the essential curing salt. Not only does sodium provide “saltiness” but it also agent whether derived from nitrate or added to meat as potentiates other flavor components to enhance the over- nitrite. The reaction products of nitrite which are deliv- all flavor (Ruusunen and Puolanne, 2005), and a mini- ered via nitric oxide are the reason for the unique and mum amount of salt is essential to acceptable flavor of distinctive properties of cured meat products.