Autoxidation of packed almonds as affected by Maillard reaction volatile compounds derived from roasting

Shelled almonds of two Italian varieties, Romana and Pizzuta, peeled and un peeled, were roasted and packed under different conditions: air (control), vacuum, and Maillard reaction volatile compounds (MRVc) derived from the ro asting process. Samples were stored for similar to8 months at room temperat ure, without light, and, at regular intervals, were collected and analyzed to evaluate the progress of lipid oxidation. Peroxide values, triglyceride oligopolymers, and oxidized triglycerides were evaluated during the storage time. Results showed that, although the MRVc atmosphere did not protect th e lipid fraction of almonds as well as the vacuum condition; nevertheless, it was more protective than the control atmosphere, showing an antioxidant effect. The effect of the natural coating was a strong protection against l ipid oxidation; in fact, only the unpeeled samples showed peroxide values l ower than the threshold of acceptability (25 milliequiv of O-2/kg of oil). Moreover, at the end of the storage period, Pizzuta almonds showed a greate r deterioration than those of the Romana variety.