Mustard pods or siliques open when fully ripe. They contain round oilseeds of very small size (about 0,03 inch / 1 mm in diameter) and covered with a crunchy skin. The number of seeds per pod varies by species: brown mustard pods typically contain up to twenty seeds while yellow mustard pods hold around six. Mustard seeds are rich in protein, antioxidants, and oil (more than 35 %) but also in glucosinolates (≈ 120 µmol/g) and sinigrin.