One of my goals for writing this post – beyond bringing about world peace through a universal appreciation for meat culminating in an enormous BBQ attended by leaders of all nations – is to shed a little light on ingredients you might come across as you scrutinize a meat product on a grocery run. In a time when more and more people are reading labels more closely to understand what is in their food (Olayanju, 2019), knowledge is definitely power. I admit: some ingredients sound a bit more like they belong in a chemistry lab than a kitchen, but ingredients must be declared by their “common or usual names” (9 C.F.R. § 317, 2020), not fanciful names to make them sound more appealing. Declaring sodium nitrite as “sodium nitrite” and not “happy salt” or some other alias is just evidence that the manufacturer is following the law. Sure, “happy salt” might be more marketable, but it isn’t a truthful representation of the ingredient.
This post, then, will be the first of several to feature ingredients commonly found in meat products with rather nebulous names. And the star of this post is… sodium phosphate! Sodium phosphate comes in many varieties, but a form widely used in meat and poultry products is sodium tripolyphosphate (STPP) (Lampila, L.E., 2013). Below is a portrait of this handsome compound. STPP is on FDA’s list of Generally Recognized As Safe (GRAS) ingredients so even though the name might make you think of chemistry labs filled with safety goggles and other protective gear, STPP has been proven to be safe to consume at the prescribed amount. In meat products, this amount is at most 0.5 percent of a formulation (Aberle, Forrest, Gerrard, Mills, 2001).
When introduced into meat – a complex system made mostly of water but also of proteins, fats, minerals and salts – STPP will increase the pH of the environment due to its basic, or alkaline, properties. As you learn in Chemistry 101, a base has a net negative charge and is eager to scoop up positively charged hydrogen ions…possibly while making a noise like sssthhhwhooop *pop*. pH is measured along a logarithmic scale to save the scientific community from having to write so many zeros, and is inversely related to the amount of free hydrogen atoms in a system: a higher number (say, 14) indicates a system with much fewer free hydrogen atoms than a system with a pH of 1. Ordinarily, meat in its very raw stage with a pH of about 5.4 is at its isoelectric point without any net charge (Glorieux, Goemaere, Steen, & Fraeye, 2017). Once STPP enters the scene and dissociates from its sodium ions, the phosphate groups – sssthhhwhooop *pop* – begin sucking up hydrogen atoms, shoving their negatively charged bits into the faces of proteins previously at ease, and forcing them into new formations. Spaces are then opened that allow water molecules to settle in and chill; this is known as an increase in water holding capacity (Aberle et al., 2001).
STPP is a powdery white substance with an appearance not much different from baking soda (sodium bicarbonate), and this comparison is fitting since both are considered bases (Markings, 2018). Both can also be used to give meat a more tender sensation due to their ability to the increase water holding capacity and separate muscle fibers (Cook’s Illustrated, 2020). In addition to their ability to increase water holding capacity, phosphates also encourage more uniform, stable color in cured products and work with ascorbates (another ingredient in cured products) to limit the development of rancidity over time (Aberle et al., 2001). Overall, sodium phosphate is a safe, effective ingredient that is used to make meat and poultry products more juicy, tender, and enjoyable. So don’t let the name put you off when you see it on a label!
9 C.F.R. § 317(f)(1), 2020. Retrieved from https://www.ecfr.gov/cgi-bin/text-idx?SID=d130a7d96ef989db1a2b83e677ab76dd&mc=true&node=se9.2.317_12&rgn=div8.
Aberle, E.D., Forrest, J.C., Gerrard, D.E., Mills, E.W. (2001) Principles of Meat Science (4th ed.). Kendall/Hunt Publishing Company.
Cook’s Illustrated (2020). Tenderizing meat with a baking soda solution. America’s Test Kitchen. Retrieved from https://www.cooksillustrated.com/how_tos/6707-tenderizing-meat-with-a-baking-soda-solution.
Lampila, L.E. (26 Aug. 2013). Applications and functions of food-grade phosphates. Annals of the New York Academy of Sciences, 1301(1). https://doi.org/10.1111/nyas.12230.
Markings, S. (26 April 2018). What is the pH level of baking soda? Sciencing. Retrieved from https://sciencing.com/ph-level-baking-soda-5266423.html.
National Center for Biotechnology Information. (11 March 2020). PubChem Database. Sodium tripolyphosphate, CID=24455, https://pubchem.ncbi.nlm.nih.gov/compound/Sodium-tripolyphosphate (accessed on Mar. 15, 2020)
Olayanju, J.B. (16 Feb. 2019). Top trends driving change in the food industry. Forbes. Retrieved from https://www.forbes.com/sites/juliabolayanju/2019/02/16/top-trends-driving-change-in-the-food-industry/#5a177c836063.
Texas A&M University (NA). Conversion of Muscle to Meat. Meat Science. Retrieved from https://meat.tamu.edu/ansc-307-honors/conversion-muscle-to-meat/.
Featured image of sodium phosphate photo credit: Great American Spice Co. (2020). Retrieved from https://www.americanspice.com/sodium-phosphate/.