The tanning agents from rhubarb, together with potassium and calcium, help the body to eliminate toxins. The malic and oxalic acids from rhubarb also stimulate digestion. However, due to the oxalic acid in rhubarb, caution is also advised: It inhibits the absorption of calcium in the body and can thus cause a calcium deficiency if consumed in large quantities.
If you like, you can add chopped nuts or seeds to the crumble. Depending on the season, a fruity combination of rhubarb and strawberries can also be tasty.
Preheat oven to 180°C (approximately 350°F).
Rinse, trim and cut rhubarb into small pieces. Mix with lemon juice and sugar and divide among 4 oven-safe ramekins.
Mix flour and sugar. Add butter and rub mixture between your palms until crumbs form. Divide crumble topping over rhubarb and bake until golden-brown, about 20 minutes.