California Almond Shelf Life: Lipid Deterioration During Storage

The effects of storage conditions on the lipid deterioration in California almond nuts and sliced were studied. Natural whole almonds with or without polyethylene (PE) packaging and blanched whole almonds and sliced with PE packaging were stored in 10 different storage conditions which were combinations of different temperatures and relative humidity levels. The peroxide values (PVs), iodine values (IVs), and free fatty acids (FFAs) were monitored during the storage. The PVs in the natural samples did not change noticeably whereas the blanched samples changed greatly, indicating that skins may have played a significant role. The IVs decreased slightly in the 1st 150 d of storage and then leveled off. The slightly faster changes in IVs in the blanched samples coincided with the greater changes in PVs in the blanched samples. The natural samples exhibited much higher FFA levels than the blanched samples after storage. In general, FFA increased with increasing storage time, temperature, and humidity. Highest levels of FFA were observed in the samples stored at high temperature and high humidity.