"To tenderize the meat" means to make the meat softer and easier to chew by using different methods such as pounding, marinating, or using natural enzymes. Full definition
While the grill heats, the chicken soaks in a yogurt - and - spice marinade which helps tenderize the meat and brings lots of tangy flavor to the dish. (finecooking.com)
The purpose of slow cooking is not only for the convenience, but, it also tenderizes the meat while cooking and allows the meat to soak up the flavors. (spendwithpennies.com)
The yogurt helps to tenderize the meat while also adding a tangy flavor that takes on a variety of spices with the greatest of ease. (cookincanuck.com)