Before eating spinach, it is recommended to blanch it for 1 to 2 minutes because spinach is rich in oxalic acid, which is the highest amount of oxalic acid in leafy greens, with 200 grams of spinach containing about 1,500 milligrams of oxalic acid.

And oxalic acid in the body will combine with free calcium ions to generate calcium oxalate crystals, not only astringent taste, but also easy to produce stones, affecting the absorption of calcium, oxalic acid is easily soluble in water, so it is recommended to eat spinach should be blanched to remove oxalic acid. Both can remove astringency, but also can greatly reduce the content of oxalic acid, spinach nutrient loss is not too big.