To achieve soft or flavorful meat, chefs often marinate their protein in some sort of potent, strong sauce. But why is this the case? Why does marination tenderize and flavor meat, and does marination really add flavor to the inside of meat?
If you have ever had a braise or a stew, you've probably noticed that the meat is noticeably more tender. This is because the addition of moist heat allows for the collagen and fibers in the meat to break down, resulting in a softer, tenderer meat. Through this process, the collagen melts and breaks down, but this often requires 12-24 hours of cooking to achieve tender meat. Chefs and home cooks have turned to marinating meat, an often unattended task and a way to significantly improve the taste and texture of meat.
When I say marinade, I'm not referring to 4 tablespoons of oil, salt, pepper, and some herbs. That's not a marinade. That's seasoning. Marinade, specifically in Asia and Africa, typically consists of a fat, such as yogurt, buttermilk or coconut milk and has a wide array of spices and sauces. These marinades almost always have an acid, such as yogurt, lemon juice, or vinegar.
Acids have a unique way of tenderizing meat. Because of their low pH, they denature proteins by disrupting hydrogen bonds in collagen fibrils. Additionally, alcohol can serve as a great marinade. Though alcohol does not have a low pH, the fats in meat are soluble in alcohol, which is why beer and wine make excellent marinades.
Shrimp Ceviche is a dish originating from Peru that has completely omitted the physical cooking of the shrimp. Instead, it requires some sort of acid, often in the form of lemon juice. This dish uses a form of Enzymatic Marination. Because enzymes increase the rate at which chemical reactions occur and also help attack the protein fibers and networks of meat, the acid and enzymes "cook" the meat itself. Fungal amylase and protease (often present in ginger, citrus and seeds), break down collagen and elastin. History suggests that in Mexico, people would wrap meat in papaya leaves because it increased tenderness.
Herbs, oils, and spices infuse the meat as it sits in the marinade. This is why 2 day-old chicken curry probably tastes better than the day it was made. Additionally, fats help at moisture to meat, because of its ability to lubricate muscle fibers, enhancing juiciness. Because the meat can hold in its juices more, marinated meat will feel tenderer and juicier.