# Nitrite: From Application to Detection and Development
## 7 Nitrite Alternatives and Degradation  
Nitrite is widely used as coloring agents and preservatives in food. In recent decades, new technologies have been explored to replace synthetic chemical preservatives with natural preservatives that have potential applications in the meat industry [126]. Also, as a coloring agent, the corresponding coloring agents are likewise being sought to replace nitrite.  
Relevant studies have shown that low doses of sodium nitrite promote the dynamic conversion of nitrosylated peptide fragments of myoglobin, thereby preserving the color of meat [127]. Therefore, the development of alternative additives is perhaps the best way to replace nitrite in meat products [128].  
Motivated by the study of the effects of nitrite on meat products, a similar low-hazard alternative has been actively sought based on similar principles of color development. It was found that the cochineal dye was observed to be adsorbed on the surface of the layered compounds and on the mortar storage. It ensured a more stable pink/red color than the other product formulations. Therefore, layered matrices adsorbed with cochineal may be a suitable alternative for obtaining the pink/red color characteristics of cooked meat products through the application of natural hybrid dyes [129]. In addition, researchers selected two strains from fermented foods with excellent myoglobin and high myoglobin conversion capacity (Met-Mb) to red nitrosomyoglobin (Mb-NO) as natural bio-coloring agents and preservatives to replace nitrite in meat products, and the application of these two strains will reduce the health risk of nitrite [130]. The effects of black tea broth on the basic composition, texture, surface color, sensory, antioxidant activity, fat oxidation, protein oxidation, and microbiological quality of steamed beef have been investigated using black tea broth as a research object, and it was found that black tea broth had comparable effects on the texture, flavor improvement, and antioxidant effects of steamed beef as those of nitrite, which provides theoretical support for the application of black tea broth as a natural alternative to nitrite in the preservation of beef [131]. In addition to this, natural extracts have been used [132] of beetroot powder (BP) [133] instead of nitrite. Similarly, it has been found that the use of fruit and vegetable powders in fried beef meatballs can also replace sodium nitrite in the meat processing industry [134]. Detailed information is listed in the Table 5.  
In food and the environment, too much nitrite tends to bring bad effects, so the degradation of nitrite is of great importance. There are chemical and biosafety problems in fermented vegetables, and biogenic amines and nitrite generation can be solved by using unique fermentation agents, high pressure, ultrasonic, and cold plasma [135]. Meanwhile, the corresponding studies have shown that electrochemical catalysis of nitro nitrate generation of nucleophilic intermediates facilitates nitrite removal and degradation [136]. In addition, anaerobic ammonia oxidation can be used for economic treatment of wastewater without addition of organic matter and aeration [137]. In the study of nitrite reduction to nitric oxide in fungi, the two synthesis mechanisms of nitric oxide provide some ideas  
\begin{table}
\begin{tabular}{c c} \hline \hline
**Substance** & **Function** \\ \hline layered matrices adsorbed with cochineal & Coloring agent, replacing the coloring effect of nitrites \\ Met-Mb (strain) & Natural biological colorants and preservatives \\ black tea broth & Antioxidant, preventing food spoilage \\ BP (beetroot powder) & Adding color and flavor to food \\ \hline \hline \end{tabular}
\end{table}
Table 5: Representative substitutes for nitrite and function.  
for the degradation of nitrite [138]. In addition, RAS (Return Activated Sludge) water treatment plants can also be used to treat nitrite [139].