Total lipid and fatty acid profiles of Coffea arabica endosperm and embryo tissues and their relationship to seed desiccation sensitivity

Abstract

As seed chemical composition may lead to different responses during drying and other post-harvest operations, the objective of this study was to determine the effect of drying rate (slow and rapid) and the concentration and composition of lipids in the embryo and endosperm tissues of Coffea arabica seeds on desiccation tolerance/ sensitivity. The total concentration of lipids and the composition of fatty acids were evaluated in isolated embryos and endosperms, and in whole (intact) seeds. Embryos had a higher total lipid concentration (23%) than endosperm tissue (8%). Linoleic acid was the predominant fatty acid, with concentrations of 48% in the endosperm and 34% in the embryo tissues. Although rapid or slow drying did not change the fatty acid profile in the embryos or endosperms, the palmitic and linoleic acid concentrations varied significantly between the embryo and endosperm. The predominance of linoleic acid in the endosperm supports the hypothesis that the endosperm tissue may be an important source of damage to the seed and may advance seed deterioration. This indicates that unsaturated fatty acids may have a greater effect on sensitivity to desiccation than the percentage of total lipids.