The answer to this dilemma was pretty obvious to me, probably because I’m attacking it from a differnet angle than you guys did. You guys are taking a microscope to a problem that deserves a much wider perspective. Lots of things stink, but we’re examining “refrigerator stink” (NOT decay stink, there’s a world of difference which I’ll explain below) and that narrows the field tremendously.
Point #1: Bacteria and fungi are the ultimate causes of the majority of stink in a refigerator.
Most of the other sources of stink will tend to diffuse out naturally, but stench with bacterial and fungal origins will build up continuously. What kinds of waste products do bacteria and fungi produce? Oh lots of things, but remember we’re only looking at the ones you’re going to find in a refrigerator. Now, you cannot look at these bacteria and fungi like you look at other cells. Bacteria typically alter their entire metabolism for the breakdown of the most abundant energy source, and the fungi your likely to find in your refrigerator are anaerobic.
For example: In milk, the bateria will quickly reorganize their metabolism to break down carbohydrates. Bacteria that try to breakdown proteins and fats, while carbohydrates are the primary energy molecule in the mix, will quickly become an insignificant part of the total population. Remember that bacteria reproduce exponentially until they’ve reached the capacity for their environment, so in an environement with half the bacteria running at 100% and half running at 98%, the 98% individuals will be virtually extinct within hours.
Point #2: The primary source of any refrigerator stink will be the immediate byproducts of the breakdown of the most abundant energy molecule in the mix (bacteria’s contribution), and the breakdown of sugars (fungi’s contribution).
Point #3: The most abundant energy molecules in a refrigerator will be sugars. The low temperature of a standard refrigerator prevents bacteria populations from reaching the levels needed to create an environment in which all of the carbohydrates would be broken down (at which point the fauna would have to resort to breaking down other molecules). Besides, most people will have thrown the food out before this could happen and baking soda would hardly be expected to tackle that level of stench, even if it were effective on it.
Conclusion #1: Bacteria will break down sugars aerobically and aerobically. Fungi will break down sugars anaerobically. The primary source of smell products will be anaerobically breakdown of sugars.
Point #4: The products of the anaerobic breakdown of sugars are (surprise surprise) acids in most fungi and bacteria.
Conclusion #2: Most of the stink in your refrigerator is directly caused by acids. I’ve also noticed that “refrigerator stink” bears more than a passing resemblance to the smell of rising dough (pre-baking, of course), which would tend to support this conclusion.
Point #5: In any chemical reaction where one reactant is suspended and the other stationary, the reactant will eventually be consumed to its equilibrium point (what that is for baking soda, I don’t know, but the volcano experiment seems to indicate that it greatly favors the products).
This is due to simple diffusion. The suspended reactant will tend to spread out evenly throughout the space available. The reactant is being consumed in one area of the space, so the suspended reactant will appear to be drawn to the stationary reactant until equilibrium is reached. If the reaction favors the products strongly enough and there is sufficient stationary reactant, the suspended reactant will eventually be almost entirely consumed.
Conclusion #3: Baking soda has the potential to consume anything which it will react with in an enclosed space.
Final Conclusion: Baking soda, a weak base, has the potential to reduce refrigerator odor. Whether or not this effect is perceptible is still open to debate.