Should You Add Fruit to a Marinade?

Many fruits contain enzymes that supposedly tenderize the meat. To test their tenderizing effects for ourselves, we added ½ cup each of crushed pear and crushed kiwi to separate batches of our Korean Marinated Beef marinade and soaked slices of rib-eye steak in each for 30 minutes. We also tossed more sliced steak in our go-to tenderizer—a solution of baking soda and water—for 5 minutes (since baking soda works on contact, longer isn't necessary) and then stir-fried all three samples per our recipe. While the baking soda–treated batch cooked up perfectly moist and tender, the pear- and kiwi-marinated meat cooked up mushy on the surface. That's because the tenderizers work differently: Whereas baking soda tenderizes by unraveling and separating the meat's protein strands, the powerful fruit enzymes (calpain in pear; actinidain in kiwi) snip the protein strands into smaller pieces that yield a mushy effect. We'll stick with baking soda when we need to tenderize meat.