The AC voltage measurement you get from your meter is called the Root Mean Square (RMS) voltage. The actual peak-to-peak voltage is greater by a factor of 1.414 (1 / squrt(2)). If you rectify an AC voltage and feed it into a capacitor to smooth it out, you will measure a DC voltage nearly equal to the peak-to-peak voltage. As soon as you start loading the capacitor, the DC voltage will go down from there.
As an important side note, your capacitors must be rated to handle that greater peak-to-peak voltage, not just the RMS AC voltage. When I was a young pup (before my engineering degree), I learned that the hard way. A nice big juicy 1000 mic cap blew up in my face when I over-voltaged it.