Method for obtaining three products with different properties from fennel (Foeniculum vulgare) seed

The objectives of this study were to determine the effects of distillation time (DT; 15-1080 min) on yield, composition, and antioxidant capacity of fennel (Foeniculum vulgare) seed essential oil (EO) as well as on the yield, composition, and properties of lipids extracted from steam-distilled fennel seeds (15-600 min). EO yield increased with increasing DT to a maximum of 1.375% at 1080 min. The principal constituent was estragole, comprising 82-91% of the overall content. Other species included limonene, fenchone, and anethole. Antioxidant capacity of the EO was essentially unaffected by DT, with capacities ranging from 11.2 to 20.6 μmol Trolox/g. The yield of lipids extracted from steam distilled fennel seeds was unaffected by DT and ranged from 21.7 to 22.8 mass%. The fatty acid composition was also unaffected by DT, and the major constituents were petroselenic (67.0-71.3%) and oleic (12.0-16.4%) acids. The concentrations of tocopherols, tocotrienols, and phytosterols were unaffected by DT whereas unsaponifiables and EO content in lipids decreased with increasing DT. Acid value, kinematic viscosity, peroxide value, and pour point increased with increasing DT, whereas density decreased. Induction period, heteroatom content, and Gardner color were unaffected by DT. As DT increased, in vitro degradability of defatted, steam-distilled fennel seeds decreased. In summary, longer DT negatively impacted feed quality of steam-distilled, defatted seed meal and lipid quality but did not significantly affect EO composition and antioxidant capacity.