Someone asked about the possible health effects of baking soda (sodium
bicarbonate) and baking powder (sodium bicarbonate+cream of tartar which is
really tartaric acid). In baked goods, the bicarb reacts with an acid
(either the 'built in' tartaric acid or some other acidic ingredient like
fruit juice, yogurt, buttermilk, etc...) to form water, carbon dioxide
(harmless gas that makes bubbles to raise the batter), and a sodium salt.
The only health effects would be from the sodium- those on low sodium diets
might need to pay attention to how much is used. But for an average batch of
say, banana bread, this really is not an issue. Two teaspoons of baking soda
has probably around 1500mg of sodium. This is the amount in a recipe that
would yeild 2 loaves, or at least 24 servings. So each slice would have
about 60mg of sodium from the baking soda. (these calculations are off the
top of my head, the actual numbers may be little higher or lower- but it's
probably a good estimate).
Hope this helps.