When buying food the most important thing is usually taste. The way stores are set up, however, we can't just go around tasting everything. Instead we use various other features of the food to get some idea how the food would taste should we eat it. Over time food producers have adapted to make these features much less reliable quality signals. So we eat a lot of bland food.

Bread starts out at maximum softness and gets harder as it gets older. Your standard American bread is incredibly fluffy, primarily because we perceive it as being fresher:

Squeezable softness had become consumers' proxy for knowing when their bread had been baked. By the 1920s, market surveys revealed that consumers didn't necessarily like eating soft bread, but they always bought the softest-feeling loaf. -- Aaron Bobrow-Strain

Bread bakers and the US government experimented with recipes until in the mid 1950s they achieved our current level of puffiness. Getting this amount of air into the bread has major trade-offs in flavor because you're pushing the yeast to its limits, but we buy it anyway because we read it as fresh.

The taste of peaches varies over a very wide range. Under-ripe peaches are hard, which makes transport easier and cheaper, but a soft peach might be mealy and bland, juicy and delicious, or overripe bordering on rotten. Trying as hard as I can to pick out tasty peaches, I sometimes get wonderful ones and other times terrible ones. Falling back on taste, I'll go stall to stall at Haymarket, buying single peaches and if they're good buying several dozen. (Perhaps making peachsicles if the flavor is good but the texture is poor.) This is pretty much the only time I use coins.

The standard supermarket apple is the Red Delicious. Shiny, with a vibrant color and good firmness it looks like it should live up to its name. Instead, it's just dull, with minimal flavor, slightly bitter skin, and a texture bordering on mealy. The Granny Smith does better, backing up its shiny green skin with crisp texture and a strong sour flavor, but it doesn't have the complexity or balance of better apples. Much of this is just the trade-off in trying to get an apple to keep well enough to supply it year round. A lot of the year, however, there are much tastier but less attractive apples that could be sold.

The problem is with using proxies for taste, so I think the real fix is to have people actually tasting the food. Offering free samples should help fix this, but most of the time I just eat the samples and don't buy. Paid samples would be interesting (drop in a quarter to try some) but I suspect people wouldn't use them. Consumer advocates who stand next to food and having tried all the options recommend what's currently good? Other ideas?

Update 2012-02-16: Also: ethylene gas ripening. We pick fruit before it's green, then expose it to hormones to tell it to become ripe just before it hits the store. This makes it look ripe while only having some of the taste of fruit that ripens on the vine/tree.