Skip to main content
ARS Home » Research » Publications at this Location » Publication #113176
Title: CORRELATION OF ANTIOXIDANT CAPACITIES TO OXYGEN RADICAL SCANVENGING ENZYME ACTIVITIES IN BLACKBERRY

Author
item JIAO, HONGJUN - GUANGXI UNIV.-P.R. CHINA
item Wang, Shiow

Submitted to: Journal of Agricultural and Food Chemistry
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/5/2000
Publication Date: 10/21/2000
Citation: Jiao, H., Wang, S.Y. 2000. Correlation of antioxidant capacities to oxygen radical scanvenging enzyme activities in blackberry. Journal of Agricultural and Food Chemistry.

Interpretive Summary: Blackberries are good sources of natural antioxidants. In addition to the usual nutrients such as vitamins and minerals, extracts of blackberries are also rich in anthocyanin, flavonoids and phenolic acids. Berry fruits have shown a remarkably high scavenging activity toward chemically generated radicals, thus making them effective in inhibiting oxidation of human low-density lipoproteins and preventing various human diseases. However, no information is available on the enzymatic system for active oxygen detoxification in the blackberry. Although our study found variation among cultivars for all the enzymes tested in this study, the antioxidant activity in blackberry juice was positively correlated to the activities of most antioxidant enzymes and the non-enzyme antioxidants. This study is significant in understanding the mechanism of antioxidant activity in blackberries and will stimulate further research in this field. The information obtained from this research should be useful to plant breeders for selecting enhanced antioxidant levels in small fruit crops.

Technical Abstract: The activities of the oxygen scavenging enzymes [glutathione-peroxide (GSH-POD), superoxide dismutase (SOD), guaiacol peroxidase (G-POD), ascorbate peroxidase (AsA-POD), monodehydroascorbate reductase (MDAR), dehydroascorbate reductase (DHAR) and glutathione reductase (GR)], the non-enzyme components [ascorbate (AsA), dehydroascorbate (DHAsA), glutathione (GSH) and oxidized glutathione (GSSG)] and their antioxidant capacity [oxygen radical absorbance capacity (ORAC)] were measured in the juice of six different thornless blackberry cultivars. The cultivar Hull Thornless contained the highest levels whereas Black Satin consistently had the lowest activities for all the enzymes tested in this study. ORAC values were also the highest in Hull Thornless and lowest in Black Satin. The highest levels of AsA and DHAsA were in the juice of Hull Thornless blackberries with 1.09 and 0.15 micromolar per g fresh weigh, respectively. Hull Thornless also had the highest ratio of AsA to DHAsA among the six blackberry cultivars studied. The correlation coefficient between the ORAC value and AsA to DHAsA ratio was as high as 0.972. Hull Thornless had the highest GSH content with 78.7 micromolar per g fresh weight, while Chester Thornless Thornless Thornless contained the largest amount of GSSG. The highest GSH to GSSG ratio was 4.90 which was seen in the Hull Thornless Thornless cultivar. A significant correlation (r=0.901) was also detected between ORAC values and GSH content. The antioxidant activity in blackberry juice is positively correlated to the activities of most antioxidant enzymes and the non-enzyme antioxidants.