Papayas Sweet, pungent papayas contain the enzyme papain, which breaks down muscle proteins. Pureed, they’re wonderful in short-soak marinades for thick flank or skirt steaks. Fresh Ginger Grated or juiced, fresh ginger contains the enzyme zingibain, which softens meat while imparting a sweet, hot kick to marinades. Fresh Pineapple Juice The fruit’s acidic juice adds bright, sharp, tropical notes to foods, and also contains the enzyme bromelain, a powerful tenderizer. Try it on pork. Kiwifruit In Korea many cooks rub the tart pulp of kiwifruit, which contains the enzyme actinidin, on kalbi, beef short ribs, to sweeten and break down the rib meat before cooking.