THE ACTIVITY AND IMMUNOREACTIVITY OF LIPASE IN STORED SUNFLOWER SEEDS

During the storage of sunflower seeds with moisture content adjusted to 6 and 18%, activity (by the diffusion method) and immunoreactivity (by the immunoblotting method) of lipase were examined. The activity of sunflower lipase ranged from 28.4 to 37.5 AU/mg protein and from 24.5 to 31.4 AU/mg protein during storage of sunflower seeds with moisture content adjusted to 6% and 18%, respectively. Protein fraction characterized by molecular weight of 78 kD on electrophoregrams of protein extract from sunflower seeds with moisture content 6% cross reacted with the anti-lipase antibodies. The presence of immunoreactive proteins was not however detected in the extracts from sunflower seeds with 18% moisture content. The enzyme immunoreactive properties appear to be affected by moisture content to a higher extent as compared to its activity, so no relationship between the enzyme activity and immunoreactivity is observed. Sunflower seeds are rich in lipids which constitute about 42-55% of seed weight. Linoleic acid is the most abundant fatty acid in sunflower oil. It accounts for approx. 55% of all fatty acids. For optimal health a human diet should be provided with “essential fatty acids”. They are necessary for proper development of human organisms and play important role in development and function of brain and retina, as well in biosynthesis of eicosanoid hormone-like substances [Linder, 1991]. The plant oils are very susceptible to deteriorative changes, thus the quality and nutritional value of seeds can be lowered. The enzyme starting unfavourable transformation of lipids is of high interest to food scientists,