Assertion: tea's tannin | /r/HasProperty | occurring chemical compounds
Facets:
value: naturally
type: MANNER
Source sentences:
text: Black tea also contains catechins (the powerful antioxidants in tea that fight cancer-causing cells and help prevent heart disease), tannins (the naturally occurring chemical compounds that give black tea and red wine their astringency), guanine (a natural stimulant) and xanthine (another natural stimulant, similar to caffeine).