Spinach retains nearly all its folate when cooked in a microwave oven; in comparison, it loses about 77% when boiled, leaching out nutrients. Bacon cooked by microwave oven has significantly lower levels of carcinogenic nitrosamines than conventionally cooked bacon. Steamed vegetables tend to maintain more nutrients when microwaved than when cooked on a stovetop. Microwave blanching is 3–4 times more effective than boiled-water blanching in the retaining of the water-soluble vitamins folic acid, thiamin and riboflavin, with the exception of ascorbic acid, of which 28.8% is lost (vs. 16% with boiled-water blanching).