Using a capacitor to smooth momentary voltage cuts
Yes you can.
Depending on the current and break time the capacitor MAY need to be large.
Voltage drop is ~=
V= T x I / C (Volts seconds Amps capacitance).You can rearrange that as
C = T x I /V or other. 

eg for a 0.1V drop for a 50 ms break at 100 mA  .
C = T x I / V
= 0.05 x 0.1 / 0.1 = 0.05 Farad = 50,000 uF  (!)
Change the values to suit.