Submitted to: Acta Horticulture Proceedings
Publication Type: Peer reviewed journal
Publication Acceptance Date: 7/1/2001
Publication Date: 9/1/2002
Citation: Interpretive Summary: Foods with high antioxidants content promote human health. Dark fruits have high antioxidant compounds. Our objective was to measure the antioxidant content of dark fruited blackberries, black raspberries, black currants, and blueberries. We analyzed samples from wild collections and cultivated types for each of these crops. We determined the antioxidant content through several different techniques. We found that black raspberries had the highest antioxidant content. Some wild species of blackberries and blue berries had high contents as measured by oxygen radical absorbtion capacity (ORAC). The black currants had high phenolic compounds and their antioxidant amounts were not composed by pigments but by other compounds (such as vitamin C). The dark fruited berries had much higher antioxidants than are found in vegetables or red fruits.
Technical Abstract: High antioxidant content of berry crops provide possible health benefits such as reduction of coronary heart disease, improved visual acuity, anti- viral and anti-cancer activity. Our objective was to determine the range of total anthocyanin content (ACY), total phenolic content (TPH) and antioxidant capacity in diverse species and cultivar germplasm of dark fruited currants and gooseberries, Ribes L, and blackberries and black raspberries (Rubus L). Ripe fruit was harvested from 22 June 2000 to 15 September 2000 from 45 berry genotypes growing in the Willamette Valley, OR. The fruit was hand-picked, stored on ice in the field, and frozen at -23 degrees C in the laboratory that same afternoon. ACY was determined by the pH differential method. Anthocyanin pigments were separated by high pressure liquid chromatography (HPLC). TPH was determined via the Folin- Ciocalteu method. Antioxidant capacity was measured by oxygen radical absorbing capacity (ORAC). ACY for Ribes nigrum L. cultivars ranged from 128 to 411 mg ACY/100g fruit; for blackberries (Rubus hybrid) from 94 to 230 mg ACY/100g uit; for black raspberries (Rubus niveus Thunb. R. occidentalis L., and R. leucodermis Douglas ex Torrey & A. Gray) from 230 to 627 mg ACY/100g fruit. Some black currants were rich sources of ACY, TP H, and ORAC through gooseberries and jostaberries were not as rich as black currants. Ribes valdivianum Phil., a Chilean native, had the highest TPH (1790 mg gallic acid/100g fruit) and ORAC 115 umol trolox equivalents/ 1g fruit, and R. occidentalis cv. Munger had the highest ACY (627 mg ACY/ 100g) of all tested Ribes and Rubus genotypes. Rubus and Ribes genotypes contain much higher ACY, TPH, and antioxidant capacities than are found in most other fruits and vegetables.