**3.1 Estimation of levels of oxymyoglobin Mb (Fe2+) and metamyoglobin MetMb (Fe3+) of raw meat emulsions and determination of color parameters**

In **Figures 1**–**4**, it is observed that in the Starch + NaNO2 sample, the oxymyoglobin levels are lower than in the Dtfg sample throughout the shelf life of the meat emulsions. In addition, in the Starch + NaNO2 sample, lower metamyoglobin values were observed after the fifth day of maintenance. These results could be correlated with the analysis of color parameters, as shown in **Figure 5**, where of particular

**Figure 1.**

*Effect of deffated Trigonella foenum-graecum seed powder in oxymyoglobin content of meat emulsions with olive oil.*

**Figure 2.** *Effect of deffated Trigonella foenum-graecum seed powder in metmyoglobin content of meat emulsions with olive oil.*

*Incorporation of Trigonella Foenum-Graecum Seed Powder in Nitrite-Free Meat Emulsion… DOI: http://dx.doi.org/10.5772/intechopen.104759*

interest is the sharp reduction of the factor *L*\* (brightness) and *a*\* (red color) in the Starch + NaNO2 sample, in contrast to the Dtfg sample.

These findings are particularly important; as in the present literature, there is difficulty in implementing strategies for the total replacement of nitrites with different plant materials. However, in some studies, an increase in color stability has been observed with the use of plant materials in meat products low in nitrite [12]. The stabilization of the color of meat products with the use of Trigonella plant powder is probably due to its high content of antioxidants, such as phenolic compounds and some steroids [27], as similar effects are observed during the incorporation of essential oils, with high content of antioxidants, in meat products with low nitrate content [26, 28]. These indications may be an important tool for the use of the Trigonella plant in the development of strategies for the reduction and replacement of nitrites in meat products, especially given that the samples of the present work were kept for 7 days without packaging in an environment with high redox potential without undergoing heat treatment.

**Figure 5.** *Effect of deffated Trigonella foenum-graecum seed powder in b\* (yellowness) factor of meat emulsions with olive oil.*
