Following heavy defeats to New Zealand and Australia's top teams, Samoa had high hopes of a breakthrough win but found themselves trailing 42-5 at halftime.
Vaifagaloa Mamoe scored Samoa's only first-half try, scooping up the loose ball following a dropped ball.
The Samoans opened the scoring a few minutes after halftime through left-winger Ausage Ausage before the Barbarians ran in four more tries to complete a comprehensive victory.
Head coach Etimani Faamoetauloa says more games against the trans-tasman rivals would help their development.