Phenolic compound are a major class of polyphenols. These 
phytochemicals are derivatives of the phenolic acids.
Subtypes:
Phenolic compounds differ from flavonoids, and they are hydroxybenzoic acid, hydroxycinnamic acid, coumrins, caffeic acid, chlorogenic acid, ferulic acid, eugenol, gallic acid, gentisic acid, vanillic acid, coumaric acid, sinapic acid, syringic acid, oleuropein, and elenoic acid.
Food Sources:
Fruits: acai berry, bilberry, cranberry, elderberry, goji berry, grapes, loganberry, mango, nectarine, olive, orange, pear, persimmon, pitaya, plum, pomegranate, quince, raspberry, sea buckthorn, strawberry, and tamarillo.
Vegetables: amaranth, beets, bell pepper, celery, corn, coriander, eggplant, garlic, green peas, lettuce, onion, parsley, potatoes, pumpkin, radish, rhubarb, and spinach .
Health Benefits:
- Are powerful antioxidants.
- Show anti-inflammatory activities.
- Demonstrate antibacterial and antiviral properties.
- Enhance immune system.
- Prevent from platelet aggregation.
- Improve HDL cholesterol level.
- Display cardioprotective activities.