Table 2.

Dietary sources of protocatechuic acid

Source	Content*	References
Açai pulp	11.7 μmol/L	[72]
Apple	31 μmol/Kg	[56]
Avocado	2.4 μmol/Kg	[73]
Beer	3 μmol/L	[57]
Bilberries	111 μmol/Kg	[58]
Bitter melon, ripe	970 μmol/Kg	[59]
Blackberries	127 μmol/Kg	[58]
Blueberries, V. arctostaphylos	9.5 μmol/kg	[60]
Buckwheat, whole grain	600 μmol/Kg	[62]
Cauliflower, raw	29 μmol/Kg	Phenol-Explorer†
Chicory	1,090-1,415 μmol/Kg	Phenol-Explorer
Currants, black	78 μmol/Kg	[58]
	357 μmol/Kg	[56]
Dates, dried	320 μmol/kg	Phenol-Explorer
Eggplant, purple, raw	48 μmol/Kg	Phenol-Explorer
Garlic	23 μmol/Kg	[74]
Gooseberry	405 μmol/Kg	[56]
Grapes, white	22 μmol/Kg	[56]
Honeysuckle, blueberried	140 μmol/Kg	[58]
Juneberries, European	159 μmol/Kg	[58]
Kiwi juice	39 μmol/L	[65]
Lentils, dried, dehulled	4.5 μmol/Kg	Phenol-Explorer
Lentils, dried with hulls	9 μmol/Kg	Phenol-Explorer
Lingonberries	195 μmol/Kg	[75]
Mango pulp	2.5 μmol/Kg	[73]
Mangosteen pulp	91 μmol/Kg	[76]
Medlar, ripe	6 μmol/Kg	[77]
Mulberries, black	119 μmol/Kg	[58]
Oil, Açai – phenol rich	4 μmol/mL	[72]
Oil, olive – virgin	3-11.5 μmol/Kg	[78]
Olive, black, raw	390 μmol/kg	Phenol-Explorer
Olive, green, raw	43 μmol/Kg	Phenol-Explorer
Onion, red	130 μmol/Kg	Phenol-Explorer
	50 μmol/Kg	[74]
Onion, white	65 μmol/Kg	Phenol-Explorer
	1.2 μmol/Kg	[74]
Pear	3 μmol/Kg	[56]
Raspberry	270 μmol/Kg	[56]
Shallot	65 μmol/Kg	Phenol-Explorer
Sorghum	165 μmol/Kg	Phenol-Explorer
Strawberry	112 μmol/Kg	[56]
Star anise	2,090 μmol/Kg	Phenol-Explorer
Wine, red	0.3-0.8 μmol/L	[79]
Wine, white	0.1-0.5 μmol/L	[79]

*Values given are for the free phenolic as well as the phenolic derived from either esters or glycosides. All published values converted to μmoles per unit volume or per Kg fresh fruit (based upon an 85% water content) or per Kg grain.

^†References for Phenol-Explorer are: [80-82].