Heat and storage effects on the flavour of peanuts.

Two peanut varieties, Giza 4 and Giza 5 were subjected to different heat treatments such as drying in solar drier at air speed 0.5 and 2 m/sec with average temperature 45 and 60 degrees C and heating in oven at 120 and 150 degrees C. The sensory evaluation of the two varieties showed insignificant differences among varieties and heating processes. A correlation between the sensory and instrumental data was found. The high sensory scores of samples heated at 150 degrees C were attributed to the presence of high concentration of pyrazines which were thought to contribute to flavour and aroma of fresh roasted peanut. A comparative study between the main chemical classes retained in peanut samples after storage for 3 months at room temperature showed that the aldehydes derived lipids increased significantly in the solar dried samples. The antioxidative components produced via Maillard reaction resulted in oxidative stability of the samples heated in oven.