You'll be surprised by at least one method.
Not everyone has a taste for mushrooms. (We know—it's crazy.) In fact, many mushroom eaters, have to sauté fungi to make them more palatable. But a new study gives even those people a reason to think twice before bathing mushrooms in butter and letting them cook over a low, slow heat. The best (read: healthiest) way to cook mushrooms, according to the research, isn't in a pan. Rather, you will reap the most health benefits from your white button, portabella, cremini, or shiitake mushrooms by grilling them—and microwaving them. (We're serious.)
First, a primer on the health benefits of fungi: mushrooms have loads of fiber, and protein—and they don't have much fat or contain too many calories, which make them an ideal side dish to any dinner. Bonus: most mushrooms have significant B vitamin levels, and a bit of zinc or selenium. In other words, they're good for you.
Scientists from Mushroom Technological Research Center of La Rioja—yes, that's a real place—looked at the various and most common ways we cook mushrooms, and recorded how each method affected mushrooms' nutritional profiles. (Specifically, the researchers studied white button, shiitake, oyster, and king oyster mushrooms, because these varieties are the most commonly consumed fungi.) They found that frying mushrooms led to the most severe protein and antioxidant loss but increased the fungi's fat content. Boiling mushrooms also led to decreased nutritional values.
On the flip side, grilling mushrooms (and even microwaving them) allowed the fungi to keep the most antioxidants, and were determined to be the best cooking methods.
"Frying and boiling treatments produced more severe losses in proteins and antioxidants compounds," wrote researcher Irene Roncero, "probably due to the leaching of soluble substances in the water or in the oil, which may significantly influence the nutritional value of the final product." But, "when mushrooms were cooked by microwave or grill, the content of polyphenol and antioxidant activity increased significantly, and there are no significant losses in nutritional value."
So, the next time you add mushrooms to your meal, may we suggest you throw them on the grill with a little olive oil and salt for flavor—and all their nutritional value?