Background: Recent patents reveal that vegetable ingredients have several applications
in novel food formulations. Many so-called antinutritional components (e.g. tannins, saponins, lectins
and protease inhibitors) have nutraceutical as well as pharmaceutical significance. Seeds of two
wild legumes of the genus Canavalia inhabitants of the coastal sand dunes of Southwest India are
known for a variety of bioactive principles (e.g. phenolics, tannins, canavanine, concanavalin and
Objective: This study evaluates the impact of Electron Beam (EB) irradiation on the bioactive
components of seeds of two coastal sand dune wild legumes Canavalia cathartica and C. maritima.
Methods: The dry seeds of C. cathartica and C. maritima were EB irradiated with different doses
(2.5, 5, 10 and 15 kGy) to follow changes in six bioactive principles (total phenolics, orthodihydric
phenols, tannins, canavanine, trypsin inhibitors and phytohemagglutinins) in comparison to control
seeds. One-way ANOVA was employed to follow the variation in bioactive components of seeds in
control and different doses of irradiation.
Results: Seeds of both legumes were devoid of orthodihydric phenols and trypsin inhibitors. In
C. cathartica, the total phenolics showed significant dose-dependent increase up to 5 kGy and decreased
thereafter. Tannin content was not altered up to 10 kGy followed by significant decrease at
15 kGy. There was no significant change in canavanine content and the phytohemagglutinin activity
against human erythrocytes was not altered. Seeds of C. maritima did not show significant
changes in total phenolics as well as tannin contents. The content of canavanine showed significant
dose-dependent increase up to 5 kGy followed by significant decrease. There was no variation in
phytohemagglutinin activity against erythrocytes A, B and O, while against AB, the activity decreased
at 2.5 kGy and further decrease was constant at higher doses.
Conclusion: The EB irradiation doses employed have selectively altered the bioactive principles of
Canavalia seeds and such treatments may facilitate to maneuver desired medicinal, nutritional,
functional and cooking properties. Besides selective changes in bioactive components the seeds
have extended shelf life.