Effect of Metal Ions on Residual Nitrite

Abstract

The effect of various metal ions on residual nitrite was studied in both a meat system and a model system. Reducing ability, nitrosylhemochrome, nitrate and p H were determined i n an attempt to explain the mechanism of loss of nitrite in the system. The control meat system contained 2% NaCl and 156 p p m of NaNO2 while treatment groups had 0.05% of metal ions (Fe", Fe"', Cu", Zn", Ca", and Mg" as chloride salts) substituted for the same amount of NaCl. The results showed that ferrous (Fe"+), ferric (Fe"), cupric (Cu'+) and Zinc (Zn") ions caused a depletion of nitrite while calcium (Ca"+) and magnesium (Mg++) ions did not have any effect on residual nitrite. The model system consisted of 25 mM PIPES buffer at p H 5.8 to which was added 156 p p m NaNOz with or without 0.05% metal ions. Only ferrous (Fe"') ion decomposed more nitrite than the control after heating. Considering the results from both systems, the mode of action for each ion appeared to be different; ferrous ion appeared to act directly as an electron donor, ferric ion acted like ferrous after being reduced, cupic ion appeared to act as an electron donor after being reduced and then as an electron acceptor, and zinc ion seemed to be effective only by decreasing the p H of the system.

Discoloration Characteristics of 3 Major Muscles From Cattle During Cold Storage

“…MRA was measured by the method of Lee and others (1981). Two grams of sample was homogenized with 10 mL of 25 mM PIPES buffer at pH 5.8.…”

Treatments for Prevention of Persistent Pinking in Dark‐Cutting Beef Patties

“…This was probably due to the lower levels of glycogen and glucose in DC meat (Apple et al, 1995). Glucose as a reducing sugar reduces ferricyanide in the reducing ability assay (Lee et al, 1981). Thus, in spite of lower ORP, DC beef had less ferricyanide reducing ability than normal beef, and a tendency for higher %Met-Mb levels ( Table 1).…”

“…Total reducing ability was measured as described by Lee et al (1981). A 2-g sample was blended with 10 mL of 25 mM PIPES {piperazine-n, n-bis (2-ethane-sulfonic acid)} buffer, pH 5.8.…”

Effect of freeze–thaw cycles on physicochemical properties and color stability of beef semimembranosus muscle

“…Metmyoglobin reducing ability was measured by the method of Lee, Cassesns, and Fennema (1981). Sample (2 g) was homogenized with 10 ml of 25 mM PIPES buffer at pH 5.8.…”