Deciphering key structural elements in the ability of phenolic compounds and plant extracts to alleviate secondary amine N-nitrosation and lipid oxidation in a cured meat model

In cured meats, nitrite provides microbiological safety, lipid oxidation control and typical sensorial properties although it is associated with N-nitrosamine formation, including cytotoxic and genotoxic ones. This work reports a new test to evaluate the antinitrosating capacity of plant extracts or phenolic compounds in an o/w emulsion, in which N-acetyltryptophan is the secondary amine target, and in processing and gastric digestion conditions (pH 5 and 2.5). Extracts from green tea, a fruit mix, grape seed or olive, evaluated at the level of 1 mM gallic acid equiv., were shown to be among the most antinitrosating extracts. Additionally, in the absence of nitrite, they markedly inhibited the metmyoglobin-initiated accumulation of triacylglycerol hydroperoxides highlighting a potent antioxidant capacity for meat preservation. The phenolic composition of the fruit mix, green tea, olive-grape mix extracts was further elucidated allowing the assessment of the antinitrosating capacity of the major phenolic constituents. Finally, this work brings out elements of molecular structure which should be helpful for plant extract selection in the aim of processing newly formulated cured and nitrite-free meat products.