Unable to read correct value from ADC10MEM
As per the comment on your question, you do need to set up everything, including IO pins, clocking source, connection to peripherals instead of digital IO, etc.

Your startup code would normally run to 10 - 100 lines depending on what you initialise.  I always initialise absolutely everything, my startup code is normally around 400 lines or so.

BUT ALSO on the F2274 (as for most of the F2 and F1 series), its very important to make sure you follow the hardware design recommendations, specifically you need the capacitor on the ADC reference voltage that appears externally. If you don't have that cap you get random rubbish in your readings.