H NMR as a simple methodology for differentiating barn and free-range chicken eggs.

The conventional intensive system produces cheap and safe chicken eggs, but exposes the animals to stress due to overcrowding on farms. This work compared the HNMR lipidic profile of chicken eggs produced in conventional and free-range systems. Sample preparation consisted of a single-step extraction and centrifugation, and the H NMR experimental time was just 3 min per sample.