were pooled from five trees. Three replications of five trees were used (three × five = 15 trees in total). Sample extracts were analyzed for their antioxidant activity by ferric-reducing antioxidant power (FRAP) assay ( Benzie and Strain, 1996 ) using
Antonios Petridis, Magdalene Koukourikou, Thomas Sotiropoulos, and Dimitrios Stylianidis
Ann Marie Connor, James J. Luby, and Cindy B.S. Tong
Variation in antioxidant activity (AA), total phenolic content (TPH), and total anthocyanin content (ACY) was examined in 1998 and 1999 in fruit of 52 (49 blue-fruited and 3 pink-fruited) genotypes from a blueberry breeding population. The species ancestry included Vaccinium corymbosum L. (northern highbush blueberry), V. angustifolium Ait. (lowbush blueberry), V. constablaei Gray (mountain highbush blueberry), V. ashei Reade (rabbiteye blueberry), and V. myrtilloides Michx. (lowbush blueberry). Using a methyl linoleate oxidation assay (MeLO) on acidified methanolic extracts of the berries, a 5-fold variation was found in AA in 1998 and a 3-fold variation in 1999 among the blue-fruited genotypes. Analyses of variance (ANOVA) revealed variation among genotypes (P < 0.0001) in single and combined years, regardless of inclusion of pink-fruited selections and adjustment for berry size. While mean AA of all genotypes did not change between the 2 years, ranking of some genotypes for AA changed significantly between 1998 and 1999. Of the 10 genotypes that demonstrated the highest AA in 1998, four were among the 10 genotypes that demonstrated highest AA in 1999. Similarly, of the 15 genotypes with the highest AA, 10 were the same both years. As with AA, mean TPH of all genotypes did not change between years and ANOVA demonstrated genotypic variation regardless of adjustment for berry size/weight or exclusion of pink-fruited selections. Changes in genotype rank occurred between years. The difference in TPH between lowest- and highest-ranking blue-fruited genotypes was ≈2.6-fold in both 1998 and 1999. Seven of the 10 highest-ranking genotypes were the same both years and TPH correlated with AA (r = 0.92, P < 0.01) on a genotype mean basis for combined years. ACY correlated less well with AA (r = 0.73, P < 0.01 for combined years). When genotypes were categorized into six groups according to species ancestry, V. myrtilloides and V. constablaei × V. ashei crosses ranked highest and second highest, respectively, for AA in both years. The groups comprised of V. corymbosum genotypes, V. angustifolium genotypes, and those with both V. corymbosum and V. angustifolium in their lineage were indistinguishable from each other. Samples from some of the genotypes were analyzed for oxygen radical absorbance capacity and ferric-reducing antioxidant power, and these aqueous-based antioxidant assays correlated well with the lipid emulsion-based MeLO (all r ≥ 0.90, P < 0.01). The three antioxidant assays may be equally useful for screening in a blueberry breeding program and the choice of assay may depend on the goal of the program and the resources available.
Hideka Kobayashi, Changzheng Wang, and Kirk W. Pomper
was quantified by ferric reducing/antioxidant power (FRAP) assay ( Benzie and Strain, 1999 ), adapted for 96-well plates ( Firuzi et al., 2005 ). Working FRAP solution was freshly made by mixing 15 mL of acetate buffer (300 m m ) and 1.5 mL of 2
Mudau N. Fhatuwani and Makunga P. Nokwanda
medicinal plant Salvia africana-lutea L. linked to metabolomic profiling BMC Complement. Altern. Med. 14 1 99 Pulido, R. Bravo, L. Sauro-Calixo, F. 2001 Antioxidant activity of dietary polyphenols as determined by a modified ferric reducing/antioxidant
Ming-Wei S. Kao, Floyd Woods, William A. Dozier, Robert C. Ebel, Chang Y. Lee, and Jun Bae Jee
The health status of Alabama's population ranks above the national average with respect to the prevalence of poor overall health indicators. Consumer knowledge of the health benefits of consumption of fresh fruit is lacking. The compositional and nutritional qualities of fruit are highly variable among states with different climate, soil, and other environmental conditions. Compositional and nutritional data of fresh fruit that reflect Alabama growing conditions is limited. Commercially fully ripened kiwi fruit (Actinidia deliciosa cvs. Fitzgerald and Hayward) were compared for fruit quality (pH, TA, °Brix, °Brix/TA, and soluble sugars), and antioxidant properties; Vitamin C (reduced, oxidized, and total), Vitamin C Equivalent Antioxidant Capacity (VCEAC), ferric reducing antioxidant power (FRAP), DPPH radical scavenging activity, total phenolics, and flavonoids. In general, `Fitzgerald' ranked higher in overall fruit quality and antioxidant properties when compared to `Hayward'.
J. Matt Fulkerson and Douglas D. Archbold*
Modified atmosphere (MA) storage of blackberries may maintain quality and increase storage life, but there is limited information about how eastern thornless cultivars respond to MA's. Because there is also a growing interest in the health benefits of antioxidants in blackberries, it would be useful to know how those levels might change during MA storage. In 2002, the eastern thornless blackberry variety Chester was stored in MA; treatments included a control, or initial levels of 20% CO2 or 5% O2. Color, pH, firmness, fresh weight, soluble sugars, titratable acidity, total antioxidant capacity, and the levels of major classes of compounds with antioxidant activity of the fruit were measured at harvest, after 1 week of MA storage at 4 °C, and after 3 additional days at room temperature to simulate common industry practices and grocery display. Total antioxidant capacity was measured using the FRAP (ferric reducing/antioxidant power) assay, and total phenolics and anthocyanins were measured spectrophotometrically. In 2002, soluble sugar levels, fresh weight, titratable acidity, and all classes of antioxidants decreased from day 0 to day 7 to day 10 while the pH increased. Color values did not change. The only trait that differed among treatments was berry firmness; from day 0 to day 7 control fruit was the most firm, and those from the high CO2 treatment were the least firm. Studies were continued in 2003 with the addition of two more eastern thornless blackberry cultivars, Hull Thornless and Triple Crown, and these results will also be presented.
Hideka Kobayashi, Changzheng Wang, and Kirk W. Pomper
Pawpaw (Asimina triloba L.), a species of the eastern United States, bears the largest edible fruit of all native trees. Relatively little is known about ripening of pawpaw, and several problems, such as short shelf life and duration of harvesting, hamper pawpaw production. While previous investigations have resulted in identifying physical properties associated with ripening, the effects on phenolic content and antioxidant capacity have not been investigated. The objectives of the study were to investigate changes in phenolic content and antioxidant capacity and to identify physical parameters of pawpaw pulp during ripening. Sample extraction of pawpaw was achieved by adding acetone (2 mL/1 g of sample) to pulp of a pawpaw cultivar, PA Golden, and then vortexing (30 s) and sonicating (15 min) the sample and solvent, prior to centrifugation (15 min) twice at 2987 × g. Folin-Ciocalteu assay and ferric reducing antioxidant power (FRAP) assay were used for the estimation of phenolic content and the antioxidant capacity, respectively. While soluble solid content increased during ripening, the hardness of the fruit decreased, confirming previous reports. The pulp of unripe fruits had the greatest phenolic content (gallic acid eq. 131.2 mg/100 g FW) and antioxidant capacity (Trolox eq. 22.7 μM/g FW), which decreased by about 20% as the fruit ripened. Of three color properties measured, chroma, an estimate of color saturation, increased with ripening, while lightness of pawpaw pulp remained the same. A high correlation was found between chroma and hardness of fruits (r = 0.62), and between phenolic content and antioxidant capacity of pawpaw pulp (r = 0.80), suggesting these parameters can be incorporated into methods to estimate the ripeness of pawpaw fruit.
M. Joseph Stephens, Julia R. Enfield, and Harvey K. Hall
determined by HPLC was quantified using purified Sanguiin H6 as a standard. Antioxidant capacity was determined by ferric-reducing antioxidant power and total phenolics through the Folin assay using methods similar to those described by Benzei and Strain
Thomas Sotiropoulos, Nikolaos Koutinas, and Anastasia Giannakoula
( Singleton et al., 1999 ) were not different among cultivars ( Table 2 ). Total phenols were expressed as milligrams gallic acid equivalents per gram fresh weight (FW). Sample extracts were analyzed for their antioxidant activity by the ferric-reducing
Chad E. Finn, Bernadine C. Strik, Brian Yorgey, Michael Qian, Robert R. Martin, and Mary Peterson
, similar total anthocyanins, and slightly lower antioxidant potential as measured by oxygen radical absorbance capacity and ferric reducing antioxidant power than ‘Marion’ ( Siriwoharn et al., 2004 ). ‘Wild Treasure’ had much higher procyanidin and ellagic