What is the purpose of oil in a marinade?

[Seven S]

Almost every recipe for marinades has an acid and an oil... what exactly does the oil do? Is it there solely for flavor, or to dilute the acid, or for anything else? Do we just add it cause we know its there for that reason or do we add it solely because thats what the recipe calls for?

[TexanFrench]

In my experience, some marinades have oil and some don't. If you are going to use the marinade as a basting sauce during cooking, it works better with a little oil, in my opinion. Also some spices disperse better in oil. But there are plenty of marinades without oil.

[Hades]

The "and" part worries and surprises me a bit. Using acids (usually along wines) makes sense because it tenderises the meat and allows the spices, herbs and other flavourings in the marinade to transfer into the meat.
Oil makes sense because it effectively takes the taste of the herbs and spices and again transfers it effectively into the meats immersed in it.
Combining bothe marinating techniques doesn't make an awful lot of sense to me. Both methods work well on their own and I don't realy see any reason to combine them.
And quite honestly, I don't know of marinade recipe's that call for both oil and wine/acid marinades
In fact I can't help but thinking that a liquid acid/wine marinade would push out the oil and make it float on top (or atleast confines the oil to "fatty islands" ) of the marinade where it doesn't realy hurt, but doiesn't realy fulfill it's puropse either.
just my opinion anyways.

[Mel!]

Personally, i think oil and vinegar taste good, together, in marinades, salad dressings and sauces. Sometimes, when i want to cut the calories, i leave out the oil, but i certainly prefer the taste, when there is oil.

Mel

[Gretchen]

Sure they get combined. The oil carries the flavors of things like garlic and it also allows the marinade to adhere to the meat better than a liquid.

[Robo410]

plus olive oil has a great taste as well!

[Seven S]

I found a good answer (to my own post!) by Shirley Corriher whom I regard a true expert in food science:

"According to Cookwise author Shirley Corriher, marinades containing oils with emusifiers mono- and diglyceride (check the labels) penetrate deeper and faster. Extra-virgin olive oil naturally contains monoglycerides and is a good choice for marinades."

http://homecooking.about.com/od/spec...almarinade.htm

[Andy M.]

As a side note, acidic ingredients do not serve to tenderize meats. It has been shown that only dairy will act as a tenderizing agent (yogurt, buttermilk, etc.).

[Goodweed of the North]

Andy is correct. Acids actually tighten the outer protien structure of the meat limiting penetration of the marinade into the meat. Brines, however, saturate the meat over time, carrying whatever flavorings contained into the meat cells.

Oils are required to release the flavors of some spices and herbs and are another flavor carrier. Though until an imulsifying agent is used, the oil and water tend to remain seperated, with the water as the more dense componant pushing oil to the top surface of the container.

A proper marinating dish only half covers the meat in marinade and requires you to flip the container half way through the marinating process. That allows the oil to sit on top of the meat and penetrate from the top down, carrying the flavors into the meat, while the marinating liquid soaks in from the sides and bottom, again carrying their water soluble flavors in. When the meat is flipped, the same actions occur to the other sides of the meat.

If a brine is used, typically, there is no acidic incredient and so the meat is simply immersed completely.

When I think about it, oil is a penetrating fluid and may very well carry flavors into the meat, in spite of the tightened protien structure from the acid/protien reaction. The acidic citrus, wine, or vinegar would flavor the outer surface while the oil would carry herbs and spice flavors into the meat. But that's just an educated hypothesis based on observation of fluid behavior. Specifically, I'm thinking about how penetrating oil has the ability to enter into places too tight for water to get into through capillary action. The same thing may be true in this application. Again, flipping the meat in a half filled container would be essential to the process.

Seeeeeeya; Goodweed of the North

[shpj4]

As far as the purpose of oil in a marinade I am sure you will find the answer

Have a great day.

Jill and Jolie