Determining the allowed temperature in drying the seed germination of sunflower (Helianthus annuns L.) and rapeseed (Brassica napus L.)

In this study, the influence of the drying temperature of free fatty acids (FFA), as well as seed germination of sunflower (Helianthus annuus L) and 00-rapeseed (Brassica napus L.) were evaluated.Thin-layer drying experiments were first conducted at 35, 40, 45, 50, 55, 60 and 65 °C air temperatures, with each product dried down to 8% wb, then drying of samples was repeated at 40, 50, 60, 70, 80, 90 and 100 °C air temperatures for two hours. Drying temperatures up to 60 °C showed no influence on FFA-content in sunflower. However, above this temperature, the concentration of FFA increased significantly.The results showed that the FFA of rapeseed decreased at higher temperatures significantly. Thus, increasing drying temperature causes decreasing the FFA-content due to lipolyse enzyme neutralisation. The germination of sunflower and rapeseed decreased significantly with increase in the air temperature. For effective seed germination, the allowed drying temperatures for sunflower and rapeseed was up to 40 °C.