Definitional. Some people might say yes, some no. To my mind, marinades contain acid to tenderize and to transfer flavor into the meat by the chemical processes of diffusion and osmosis.
People use the term "marinate," even more loosely. It's fairly common to refer to any long immersion in wet seasoning as marinating, and even to distinguish a "dry marinade." I don't disagree with people who use the terms, it's only language and there's no real right or wrong. I just like to make sure everyone's on the same page before we get into the subject too deeply.
I mentioned diffusion and osmosis. These process are "powered" by differences in the seasoning outside of the food, the liquids within, and the tendency of different solutions of similar density to become a single homogenous solution. Certain differences power the processes more strongly than other -- particularly acid and salt. Acidic and/or salty solutions best penetrate in the interstitial spaces between cell walls (diffusion) and possibly across cell membranes themselves (osmosis).
Besides carrying flavor, acidic marinades also begin the process of denaturing proteins -- which is part of tenderizing. Without acid the marinade is far less effective at doing what you want a marinade to do.
You may want to call soaking meat in olive oil with onion, garlic, and oregano in it, "marinating," and I'm not going to say you're wrong. I use different words though, and want you to know where I'm coming from when I answer your questions.
[/quote] Salt is alkaline, right ?[/quote] All alkalis are salt. But not all salts are alkaline. Ordinary table salt, NaCl is neither acid nor basic but neutral.
From a bacterial/viral standpoint ... no way is practical.
My answer might have been too glib and insufficiently scientific. Poultry is not only a prime source of dangerous bacteria and noroviruses, it's known as one and inspires a geat deal of fear.
Perhaps the fear is overblown, and perhaps the marinade can be sterilized with heat. But it's not worth taking the chance, and it's not worth treating the food in a way your diners would find frightening or objectionable.
Red meat carries a lower risk of bacterial and viral contamination than poultry -- so it's safer to use the marinade. But if you return to my original answer you'll also see I told you to avoid using the liquid from long marinades. There's really nothing all that special about a used marinade, and no reason a sauce can't be built around the same theme out of fresh ingredients. My recommendation is that when you feel a used marinade will make a good base, you only use it when the marinating process was less than an hour, occurred in the refrigerator, and did not involve poultry.
Hope this helps,