In the basic game of Race for the Galaxy (no expansions), what happens during the consume phase if none of your cards give you any consume powers? Do those goods get consumed anyway without giving you VP's?
No, the goods remain. Goods are only discarded if they are used to invoke a Consume power (or Traded). If you do not have enough Consume powers to use all your goods (or none at all), the goods remain.
Furthermore, although you may not decline to invoke a Consume power, you get to choose what order your Consume powers are invoked in. This may allow you to avoid invoking certain powers by leaving the "wrong" goods left over. For instance, consider this situation: you have a Blue good, a Green good, a Consume power that consumes a Blue good for 1 VP, and a Consume power that consumes any good for 1 VP. If you wanted to, you could activate the first power using the Blue good and the second power using the Green good, and gain 2 VP. However, you could also choose to activate the second power using the Blue good. That leaves you with 1 VP, no remaining powers that can be used, and a Green good left over. As the rulebook puts it (p. 6):
Consumption is mandatory. However, consume powers can be invoked in any desired order, even if this results in some unconsumed goods left over that could have been consumed with a different order (due to their kinds not matching the player’s remaining unused consume powers).