S-Nitroso-N-acetylcysteine Generates Less Carcinogenic N-Nitrosamines in Meat Products than Nitrite

Abstract

Nitrite reacts with secondary amines to form N-nitrosamines (N-NA), which lead to gastrointestinal cancers. The aim of this study was to compare nitrite with S-nitrosocysteine (Cys-SNO) and S-nitroso-N-acetylcysteine (NAC-SNO) with respect to N-NA formation, which was evaluated by determining the conversion of N-methylaniline to Nnitrosomethylaniline. Under neutral and acidic pH conditions, N-NA formation rate was nitrite > Cys-SNO > NAC-SNO. In the presence of copper or nucleophiles, NAC-SNO generated much less N-NA than Cys-SNO. Nitrite and Cys-SNO produced higher amounts of N-NA in the presence of oxygen, whereas NAC-SNO was almost oxygen insensitive. In meat in the stomach medium, NAC-SNO produced much lower amounts of N-NA than other additives. In heated meat, Cys-SNO and NAC-SNO generated the nitrosyl-hemochrome pink pigment, better than nitrite. In conclusion, NAC-SNO was much less reactive for N-NA formation than nitrite and Cys-SNO in conditions relevant to meat production and stomach digestion.

Nitrite accumulation during storage of tomato fruit as prevented by hydrogen gas

“…[24] Several approaches, including the addition of vitamin C or other antioxidants, have been applied to reduce nitrite content and nitrosamines formation. [6,24,25,48] Accordingly, our results imply a possible interaction between H 2 and vitamin C governing NR-mediated nitrite accumulation. It has been reported that H 2 could also be an antioxidant, not only selectively scavenging reactive oxygen species (ROS), [49] but also interacting with or modulating vitamin C metabolism.…”

“…As a major source of antioxidant, vitamin C can react with many clinical health-risk factors, including nitrite. [6,24,25] To investigate the possible role of vitamin C in the above observed H 2prevention of nitrite accumulation, a time-course analysis of vitamin C level during tomato fruit storage, was determined by HPLC after treatment in the presence or absence of H 2 . Similar to the reduction of endogenous H 2 production (Figure 1c), decreased vitamin C levels were observed.…”

“…Sodium and potassium nitrite, which are usually referred to as nitrite salts, have been widely used in meat production industry as preservatives for many centuries. [6] However, nitrite has adverse effects upon human health. Firstly, nitrite can increase methemoglobin content by reacting with hemoglobin, transforming the ferrous iron to the ferric state and then arresting or decreasing the oxygenation of blood.…”

“…[23] Furthermore, some antioxidant compounds that are found in food, for example, vitamin C, could inhibit nitrite accumulation. [6,24,25] Because of nitrogen assimilation by plants due to nitrogen fertilization, eating fruit and vegetables is one of the main pathways to ingest nitrite. [18,20,26] In addition, during storage after harvesting, nitrite content has been found to increase constantly.…”

S-Nitroso-N-acetylcysteine (NAC-SNO) as an Antioxidant in Cured Meat and Stomach Medium

“…N-NA formation rate was nitrite > cys-NO > NAC-SNO, and the sum formation of N-NA by S-nitroso-Nacetylcysteine (NAC-SNO) in the product and stomach was 99% less than nitrite. 27 As NAC-SNO seems to be a good candidate molecule for the replacement of nitrite in meat products, the aim of the present study was to compare the inhibition of meat lipid peroxidation and antioxidant tone achieved by NAC-SNO to nitrite, in cured meat, during processing, storage, and digestion in stomach medium.…”