[14] especially lysine , threonine , tryptophan , and the sulphur-containing amino acids. [15]   Minerals Rich in iron (60–100 ppm), zinc (20–30 ppm) and selenium (20–50 ppb). [16] [17]   Antioxidants 10–200 ppm of rutin and 0.1–2% of tannins [18]   Aromatic compounds Salicylaldehyde (2-hydroxybenzaldehyde) was identified as a characteristic