Yes, acid ingredients unwind the fibers and actually do tenderize. But, too much acid - vinegar, hot sauce, wine - in a marinade or being marinaded for too long can have the opposite effect causing the meat to be stringy and tough.

Brining also does the same thing through osmosis. Since the cell wall is semi-permeable, the water and salt can pass into the cell, but the proteins cannot pass out of the cell. Once inside the meat, salt causes the strands of protein to "unwind" changing the structure. The strands become tangled together, trapping moisture. When the meat is cooked, the tangled proteins solidify and form a barrier that keeps the moisture and salt in the meat.

So Mr. Windsor was right ... and wrong.

I've salted things like duck and pork overnight for years because it really does improve the flavour and actually prefer it to acid marinades. Dry marinading with salt and diced vegetables - carrots, onions and celery - really tenderizes well too.

Thanks for letting me wear my food science hat.

Karen