Cutting out nitrite and controlling aroma in cooked ham - The ‘Jambonol’ project

Les Cahiers de l'IFIP, 9(1), 34-46.
This study focused on pathways to reducing or even eliminating added nitrite in cooked ham without losing the typical cooked ham aroma. The aim was to use all-natural added ingredients to obtain a tasty ham with a sufficiently long shelf life. The ‘Jambonol’ project harnessed research on alternatives to nitrite that work on the key aroma-active compounds that produce cooked ham flavour by adding natural precursors of the aroma-active compounds and adding natural antioxidants. Experiments using potential precursors to the odour-active compounds in cooked ham showed that these key aroma compounds are produced by the thiamine degradation process. The research managed to compute the relationship between thiamine concentration in the ham and concentration of odouractive compounds formed in the cooking process. Our research has shown the role played by nitrite in the development of cooked ham aroma, which results from the perceptional balance between the odour-active sulphur compounds and odour-active lipid oxidation products formed during cooking or storage of the ham. The antioxidant action of nitrite controls this balance by limiting the formation of oxidation-product compounds that would otherwise mask the ‘cooked ham’ flavour notes brought by the odour-active sulphur compounds.
Among the set of active ingredients tested, four antioxidant compounds—ascorbic acid, malic acid, catechin, and quercetin—proved to be relatively effective alternatives to nitrite in terms of oxidative profile. Four of the natural plant extracts tested—cranberry, acerola, green tea, and onion—equalled or bettered the antioxidant performances of sodium nitrite, and without creating flavour/ odour defects. These extracts produced a more intense ‘cooked ham’ aroma than nitrate-free ham and almost reached the level of nitrite-cured ham. Adding 100 mg of thiamine per 100 g of brine effectively lifted the ‘cooked ham’ head notes in nitrite-free acerola + cranberry and acerola + onion formulations. The heat-process-driven degradation of thiamine induced ‘cooked ham’ head notes that proved near-identical to a nitrite-cured ham.