Sugar composition was measured as follows: Aliquots (0.3–0.6 g) of milled seeds were weighed and incubated stirring with 2 ml of 72% (w/w) sulfuric acid for 1 h at room temperature, then diluted with 56 ml of distilled water (final conc. 4% (w/w)) and autoclaved for 1 h at 121°C.