Neutral and polar lipid phase transition of soybeans with various saturated fatty acid contents

Soybeans with modified saturated fatty acid compositions sometimes have lower seed germination rate or other undesirable agronomic traits. To determine if seed germination could be related to the melting transitions of their lipids, triacylglycerols (TAG) and phospholipids (PL) from soybeans with a wide range of saturated fatty acid compositions were examined by differential scanning calorimetry. The melting transition temperatures of both TAG and PL increased with increasing palmitate and stearate percentages. The mean melting points of the various lipids calculated on the basis of the melting points of their fatty acids correlated with the observed transition temperatures. Increased lipid saturation and elevated phase transition temperatures may have contributed to the reduced germination and seedling growth rates of these modified seeds.