Previous research suggested that
Ricinus communis
may be used for soil remediation and oil production.
However, the quality of the oil and bioproducts under
polluted conditions need to be tested to be assured of their
potential use in biofuel production with environmentally
friendly bioproducts (cake, seed coats and biomass). Oil
characteristics and metal concentrations in oil, cake (deoiled
seeds) and seed coats, as well as the shoot carbon
content were analyzed. The oil contents of palmitic and
oleic acids from plants growing in polluted mine tailings
were comparable to those for plants grown under nonpolluted
conditions. Linoleic acid content was significantly
higher in oil of plants from mine tailings, which enriches
the fuel properties. Cadmium and lead were mainly concentrated
in the seed coat, whereas copper in the cake.
Castor bean oil had low concentrations of cadmium, lead,
zinc, nickel, manganese and copper-free. Cake and seed
coats can be useful for soil fertilization applications since
the metal concentrations are below safety regulations. The
biomass carbon was around 43 %, which suggests it may
be used for biogas production. These properties make
castor bean valuable for its oil and bioproducts even when
growing at metal-polluted sites. However, agronomic
optimization is needed in order to produce higher plant
productivity.
