Add the baking soda to the cut meat and then wash it off. Measure about a teaspoon in your palm and then sprinkle it over the thinly sliced meat from high up. This way you get a thin layer over all the meat. Wash after some time (you can do it overnight). There is an eHow that you may follow
The baking soda will work like other meat tenderizers, by denaturing the proteins on the surface of the meat, so it should work on pork or chicken as long as the baking soda is on the meat (and not the skin or fat). The tenderizers penetrate the meat very slowly, millimeters per day at refrigerator temperatures, faster at cooking temperatures, so in practice it will only work on thin slices. If you use thicker pieces, you will still change the meat's surface texture.
If you use the baking soda straight into the dish in the same proportion (some people like it this way), adjust your salt accordingly, as the baking soda will make the dish salty.
The paragraph you quoted is utter nonsense.
Milk contains absolutely no factors which will tenderize anything. Tenderization is a process whereby protein strands are broken down, resulting in shorter strands, resulting in a more tender product. A lot of substances and physical processes will tenderize, to a greater or lesser extent, sometimes subject to other factors: acids, bromelain, a similar compound found in mango, physically pounding the meat, etc. Milk is none of those things.
Further, simply limiting the cooking temperature to under 212F/100C will not, in fact, guarantee a tender and moist result. To see this for yourself, boil a chicken breast in water or milk for a while. It will never go over the boiling point of water, but if you leave it too long? Dry, nasty chicken.
As Mike said in his answer, braising will result in a more tender end product; the length of cooking time plus the liquid medium helps to moderate the temperature and cook the protein very, very slowly. This retains more moisture within the product, and prevents protein strands from bunching up very tightly (which, really, is the same thing: protein strands force water out of meat as they constrict; prevent or ameliorate the constriction and you will have much moister and more tender meat). It is also worth noting that braising is always done at significantly below boiling temperatures; one braises at a simmer at most, more in the 60-80C range.
Milk is often used with certain proteins due to its facility in absorbing unpleasant odours or flavours. Liver is the classic example, but milk is also often used with sweetbreads and fish (amongst other things) to help draw off the funkier aromas before cooking. I do not know the specific scientific mechanism behind why this works; I suspect it is something to do with the fat molecules in the milk itself, which suggests that any fatty liquid would have the same effect.
So, for the short answer, see my first sentence.
Best Answer
Yes Kiwifruit contains Actinidin, which is a great meat protein tenderiser
But it tastes crap, it is not a good accompaniment for meat, especially chicken. It is way too sweet tasting, sort of like serving chicken with fruit jam (preserve), if you like that, go for it!