Lipid deterioration during storage of Almond kernels (Shalimar var.)

Almond is one of the most valuable nuts in the world. Due to the high presence of these unsaturated fatty acids almonds are highly susceptible to immediate lipid oxidation which impairs their nutritive as well as sensory quality. The aim of the research was to determine the best storage conditions for almond kernels. Almonds of uniform size were manually decorticated and extracted kernels were mechanically dried at 40 C to a final moisture content of 4.20% after antioxidant treatment (0.015% BHA + 0.015% BHT). Both treated and untreated samples were packed in LDPE and Laminates (under vacuum) to monitor the changes in quality attributes under ambient (19C±2C, RH 22%) and accelerated (35 C±1C, RH 60-70%) storage conditions for a period of 270 days. Antioxidant treated samples packed in vacuum laminates and stored under ambient conditions proved significantly superior by exhibiting minimum free fatty acid value (0.75 mg/g) and minimum peroxide value (109.99 meq/100g) compared to untreated kernels packed in LDPE under accelerated conditions throughout the storage period. The peroxide value and fatty acid value in the treated samples did not change noticeably whereas the untreated samples changed greatly, indicating that antioxidant treatment and packaging have played a significant role. Higher free fatty acid levels than the blanched samples after storage. In general, free fatty acids increased with increasing storage time, temperature, and humidity. Highest levels of free fatty acids were observed in the untreated samples stored at high temperature and high humidity.