Adaptation of a Method for the Determination of Soluble Orthophosphates in Cooked and Uncooked Pork Containing Acid‐Labile Poly‐ and Pyrophosphates

Abstract

A calorimetric method developed for determining p,g levels of soluble orthophosphates in soils was successfully used in cooked and uncooked pork to monitor hydrolysis and residual levels of added sodium acid pyrophosphate (SAPP). The method is based on the formation of blue color by reacting existing orthophosphate with molybdate ions in an acid medium and preventing further reaction by rapidly sequestering excess, unreacted molybdenum ions with a citrate-arsenite reagent. The usefulness of the method to monitor poly-and pyrophosphate hydrolysis in meat is discussed.

Lnsolubilization of Orthophosphates in Fresh or Cooked Ground Pork

“…The formation of orthophosphate as a result of the enzymatic hydrolysis of SAPP was observed in fresh meat samples that received the polyphosphate alone or in combination with OR-THO (Table 3). This observation agreed with similar results obtained with beef by Awad (1968) and with those of our previous work with pork (Molins et al, 1985). After 4 days at 5"C, uncooked meat that received 5000 pg/g of SAPP had approximately the same soluble orthophosphate as ground pork treated with the same concentration of ORTHO.…”

Effect of temperature on phosphate diffusion in meats

“…The modified spectrophotometric ammonium molybdate method (AOAC, 1990, 973.55-56;Lee et al, 1998;Molins, Kraft, & Olson, 1985;Ü nal et al, 2004) was used to determine the phosphate levels both in meat samples and the solutions during dipping time. This method is based on hydrolyzing all phosphates into orthophosphates by using sulfuric acid and spectrophotometric measurement (at 690 nm; UV/VIS spectrophotometry, Lamda EX201, Perkin Elmer) of the blue color from the reaction of orthophosphates with ammonium molybdate and ascorbic acid.…”

Experimental theory, fundamentals and mathematical evaluation of phosphate diffusion in meats

“…Batista et al (1999) determined the total phosphorus content of dog cockle meat samples by ashing the samples followed by acid digestion and colorimetric measurement of yellow color. Molins et al (1985) used a modified spectrophotometric method to determine the soluble orthophosphates in cooked and uncooked pork containing acid-labile poly and pyrophosphates. Then, Lee et al (1998) re-modified this method to determine the soluble orthophosphates in beef.…”

“…Therefore, it would be an important issue to find out about the added amount of phosphates in the products. For this, an experimental determination would be needed, and it requires more attention due to the presence of naturally occurring orthophosphates in the meat products (Molins, Kraft, & Olson, 1985).…”