Flavor
A good marinade contains flavorings, spices, herbs, etc. Because a marinade is also acidic it carries these flavors into foods. Of course it can only travel so far, so marinating a thick roast will not get the added flavor you would get with a thin cut, but it is still beneficial. When selecting a marinade look for flavor that will compliment the food you are marinating.
Juiciness
Marinades typically contain some kind of oil. Olive oil is my particular favorite. In fact the best oil to use is a light oil containing mono- and/or diglycerides. These natural emulsifiers help penetrate meats faster than other oils, so check the labels for a good marinade oil. The oil also serves to hold in moisture on meats and to reduce the moisture loss during cooking.
Healthier
cooking meats over a direct flame heterocyclic amines (HCA)’s are created. These potentially cancer-causing agents can be reduced by, as much at 99% when foods are marinated in an acidic marinade at least that’s what the American Cancer Research Institute says. An acidic marinade acts by keeping HCA’s from forming on meats.
tender
The acids in a marinade that contains vinegar, citric juices or other acidic liquids acts to breakdown protein chains in meats, making them more tender. However you need to make sure that you do not let food sit in marinades for too long. Surfaces in direct contact with a marinade can become soft and mushy, not something you would want to serve. This is particularly important with fish and seafood, which can actually cook, in an acidic environment. Do not marinate foods longer than called for.
