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
Attila Hegedűs, Emőke Balogh, Rita Engel, Béla Zoltan Sipos, János Papp, Anna Blázovics, and Éva Stefanovits-Bányai
synergistic combinations in a complex mixture of several thousand phytochemicals ( Liu, 2003 ). Berries are known to possess outstanding antioxidative power ( Cho et al., 2004 ; Hannum, 2004 ; Moyer et al., 2002 ). The antioxidant capacity of berries was
Nikolaos Koutinas, Thomas Sotiropoulos, Antonios Petridis, Dimitrios Almaliotis, Emmanuil Deligeorgis, Ioannis Therios, and Nikolaos Voulgarakis
sodium hydroxide (NaOH)], and ascorbic acid (mg/100 g fresh weight) by oxalic acid (1%) as described by Koukourikou-Petridou et al. (2007) . In addition, ferric-reducing antioxidant power ( Benzie and Strain, 1996 ) and total phenols ( Singleton et al
Chenping Xu and Beiquan Mou
) total antioxidant capacity, ( B ) ferrous ion chelating ability (FICA), and ( C ) reducing power 4 weeks after treatment. The values are means of eight replicates ± se . FICA was calculated as the absorbance difference ( A ) between control and sample
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
-hydroxy-6,7,8,3′,4′,5′-hexamethoxy-flavan-3-ol ( Mashimbye et al., 2006 ), tannins ( Mudau et al., 2007b ), and antioxidants ( Mogotlane et al., 2007 ). Although these secondary metabolites demonstrate their fundamental importance as quality control
Jing Huang, Ya-liang Xu, Fa-min Duan, Xu Du, Qi-chang Yang, and Yin-jian Zheng
; after being shaken well, the absorbance at 517 nm was measured as Ac. DPPH free radical scavenging rate = [1 – (Ai – Aj)/Ac] × 100%. Antioxidant power measurement. The determination of the ferric-reducing antioxidant power was conducted according to
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.
Artemio Z. Tulio Jr., Mustafa Ozgen, R. Neil Reese, Steven J. Schwartz, Qingguo Tian, Gary D. Stoner, A. Raymond Miller, and Joseph C. Scheerens
Anthocyanins in black raspberry extracts may play a key role in the regulation of oncogene expression in cancer cell cultures. Variations in anthocyanin levels of `Jewel', `Mac Black', and `Bristol' black raspberries grown at seven commercial farms in Ohio were investigated using HPLC and uv-vis spectrometry. Cyanidin-3-rutinoside (cy-3-rut) and cyanidin-3-(2G-xylorutinoside) (cy-3-2-xyl), the two major compounds present in all cultivars (≈2:1), were highly correlated with total anthocyanin contents. Sample variation in total anthocyanin, cy-3-rut, and cy-3-2-xyl levels was greater among commercial farms than among cultivars grown at the same location. The antioxidant activities of cy-3-rut, cyanidin-3-glucoside, cyanidin-3,5-diglucoside (cy-3,5-diglc), and pelargonidin-3-glucoside from purified extracts were determined using the free radical scavenging assays DPPH and ABTS, and the ferric reducing power assay FRAP. All pure anthocyanins showed strong antioxidant potentials except for cy-3,5-diglc. Cy-3-rut was identified and quantified as the dominant anthocyanin in black raspberries and was also the most potent antioxidant. Results suggest that anthocyanins, cy-3-rut in particular, may function as the primary antioxidants in black raspberries. Genetic and environmental variation in the anthocyanin contents necessitate characterization of the antioxidant and anthocyanin levels in fruits from any given source prior to measuring biological and medicinal activities.