Carotenes rhymes with:
nicotine's, argentines, bernstein's, feldstein's, finkelstein's, hammerstein's, libertines, mangosteens, nicotine's, philistines, protein's, proteins, quarantines, seventeens, springsteen's, thirteen's
Carotenes sounds like:
cardenas, cardenas's, carting, cartons, cartooning, cartoons, chardonnays, charting, cording, cortens, cortens', cortinas, cortines, courtemanche, courting, crating, creating, creations, credence, credenza, crediting, croatian's, croatians, croatians', crowding, curtains