Disclosed herein are processes for converting an unsaturated fatty acid into a saturated branched-chain fatty acid through a zeolite-catalyzed process and methods of economically regenerating and reusing the zeolite catalyst. The processes include subjecting the unsaturated fatty acid to an isomerization reaction to result in a selective conversion of the unsaturated fatty acid into the saturated branched-chain fatty acid. The reaction occurs in the presence of (i) an activated zeolite catalyst, (ii) an effective amount of water, and (iii) optionally an oligomerization reducing agent. The spent zeolite catalyst may be regenerated by heating to create a regenerated zeolite catalyst that is functional for use as the activated zeolite catalyst.