Search

Flaxseed (Linum usitatissimum L.) is well known for its health benefits and chemical composition. This study aimed to evaluate the dynamic changes caused by germination in vitamin C, phenolic compounds and antioxidant activities of flaxseed. It was observed that eight-day germination of flaxseed sprouts caused increases in phytochemical contents, that is 22.1-fold increase in vitamin C, 2.67-fold increase in phenolics and 5.48-fold increase in flavonoid contents as compare to initial concentration in flaxseeds on dry weight basis. The stimulation was also noted in the three identified phenolic acid ingredients including caffeic acid, p-coumaric acid and ferulic acid. Similarly, the total PSC and ORAC values of flax sprouts at day 8 increased by 3- to 4-folds compared to nongerminated flaxseeds. It is revealed that comparatively, 8-day germination of flax sprouts leads to a significant increase in vitamin C, phenolic constituents and total antioxidant activities than those of flaxseeds. [ABSTRACT FROM AUTHOR]

Understanding the influence of processing operations such as drying/dehydration, canning, extrusion, high hydrostatic pressure, pulsed electric field, and ohmic heating on the phytochemicals of fruits, vegetables, and grains is important in retaining the health benefiting properties of these antioxidative compounds in processed food products. Most of the previous investigations in the literature on the antioxidants of fruits, vegetables, and grains have shown that food-processing operations reduced the antioxidants of the processed foods, which is also the usual consumer perception. However, in the last decade some articles in the literature reported that the evaluation of nutritional quality of processed fruits and vegetables not only depend on the quantity of vitamin C but should include analyses of other antioxidant phytochemicals and antioxidant activity. Thermal processing increased the total antioxidant activity of tomato and sweet corn. Most importantly, analysis also depends on the condition, type, and mechanism of antioxidant assays used. This review aims to provide concise information on the influence of various thermal and nonthermal food-processing operations on the stability and kinetics of health beneficial phenolic antioxidants of fruits, vegetables, and grains. [ABSTRACT FROM AUTHOR]

Phenolics are suggested to be the major bioactive compounds responsible for the health benefits of tea. Seven types of tea were extracted using boiling water. The extraction kinetics was investigated. To more fully characterise the antioxidant profiles and possible associated health benefits of these tea types, the total water-soluble solid content, phenolics, flavonoids, and antioxidant and antiproliferative activities were quantified. Green tea leaves ( GTL) were found to have the highest phenolic content (128.7 ± 1.7 mg g−1 , P < 0.05), followed by teas of decaffeinated green tea bag (d GTB), green tea bag ( GTB), black tea bag ( BTB), decaffeinated BTB, black tea leaves and oolong tea leaves ( OTL). Among the three leaf teas, GT displayed the greatest antioxidant activity (4850.2 ± 60.7 μmol g−1, P < 0.05), followed by black tea ( BT) and oolong tea ( OT). As for the four bag teas, decaffeinated GT possessed the strongest antioxidant activity (4431.1 ± 335.0 μmol g−1, P < 0.05), followed by GT, BT and decaffeinated BT. The results display that phenolic/flavonoid content well correlated with antioxidant activity. Proliferation of three human cancer cells was significantly inhibited in a dose-dependent manner after exposure to some tea extracts. This may influence consumers in selecting the type of tea and tea brewing times, exhibiting greater health benefits. [ABSTRACT FROM AUTHOR]

Abstract: Grapes are rich in phenolics, flavonoids and resveratrol, which have been suggested to be responsible for their health benefits. The concentrations of phenolic, flavonoid, anthocyanins and resveratrol of 14 grape varieties grown in the Finger Lakes area of New York State were examined. Among the varieties tested, Cabernet Franc and Pinot Noir contained the highest total phenolic content with 424.6±3.8 and 396.8±12.4mg/100g, respectively. The total flavonoid content of Pinot Noir (301.8±6.2mg/100g) was around 3.1-fold higher than that of Baco Noir. Baco Noir had the highest resveratrol content (571±30μg/100g) of the varieties tested. Cabernet Franc possessed the highest antioxidant activity. Total antioxidant activities of grape extracts are well correlated with total phenolic content. The proliferation of Caco-2, HepG2 and MCF-7 human cancer cells was significantly inhibited in a dose-dependent manner after exposure to Pinot Noir, Cabernet Franc, Chardonnay, Catawba, Concord, Sheridan, Niagara and Riesling. The results suggest that phytochemicals in the selected wine grapes have potent antioxidant and antiproliferative activities. [Copyright &y& Elsevier]

The physical qualities, antioxidant content and activity, and antiproliferation activity of ‘Jewel’ strawberry fruit that were harvested at the white tip and red ripe maturity stages and stored in 65 or 95% relative humidity (RH) at 3 and 10°C for 12d were studied. Overall quality and firmness of fruit harvested at the red ripe stage declined more rapidly than at the white tip stage, and decreased more rapidly at 10°C than at 3°C in fruit of both maturity stages. RH did not affect fruit quality in any treatment. Lightness (L*) and hue angle decreased, and anthocyanin concentrations increased, more rapidly at 10°C than at 3°C in the white tip fruit. The L* of red ripe fruit decreased by day 3 and was maintained during the rest of the storage time. The initial anthocyanin concentrations of red ripe fruit were about five times greater than that in white tip fruit and declined during the storage. Total flavonoid and phenolic concentrations, and total antioxidant activity of fruit harvested at the white tip stage were greater than those harvested at the red ripe stage. These differences were maintained during the storage, except for red ripe fruit, where concentrations and activity decreased rapidly by day 12 in fruit stored at 10°C, especially at 95% RH. Total ascorbic acid concentrations of white tip fruit were lower than in red ripe fruit at harvest, but increased slightly over time, while those in red ripe fruit were relatively stable until they decreased at 10°C at 12d. Overall changes of total antioxidant activity were similar to those of total flavonoid and total phenolic concentrations, but not anthocyanin or ascorbic acid concentrations. Fruit quality was correlated with firmness and color attributes as well as with total flavonoid and phenolic concentrations and with antioxidant activity. A 50gL−1 concentration of strawberry extracts inhibited HepG2 human liver cancer cell proliferation by approximately 80%. The EC50 of antiproliferative activity of strawberry fruit value was not affected by the maturity stage at harvest or by storage temperature. [Copyright &y& Elsevier]

The phytochemical content and antioxidant activity of eight varieties of brown rice (BR) are reported. The total phenolic contents of BR ranged from 72.45 to 120.13 mg of gallic acid equiv./100 g. The phenolics from bound fraction contributed 40.6–50.2% of the total phenolic content. The total flavonoid contents of BR ranged from 75.90 to 112.03 mg catechin equiv./100 g. The flavonoids from the bound fraction contributed 26.9–48.2% of total flavonoids. Trans -ferulic acid was the predominant phenolic acid in BR. Total trans -ferulic acid content ranged from 161.42 to 374.81 μg/100 g. The percentage of trans -ferulic acid in bound fraction ranged from 96.4% to 99.2%. Only α- and γ-tocopherols and -tocotrienols were detected in BR with α-tocopherol and γ-tocotrienol being the predominant. The total peroxyl radical scavenging capacity (PSC) of BR ranged from 18.29 to 40.33 mg vitamin C equiv./100 g. The bound fraction contributed 67.2–77.2% of total PSC. [ABSTRACT FROM AUTHOR]

Phenolics including flavonoids are suggested to be the major bioactive compounds contributing to the health benefits of fruits and vegetables. The objective of the study was to determine the total phenolic and flavonoid contents, oxygen radical absorbance capacity (ORAC), peroxyl radical scavenging capacity (PSC), cellular antioxidant activity (CAA) and antiproliferative properties of selected cerrado fruits named gabiroba (Campomanesia cambessedeana Berg), murici (Byrsonoma verbascifolia Rich) and guapeva (Pouteria guardneriana Radlk). Gabiroba fruit showed the highest amount of total phenolics (851.0±40.7mg/100g fruit) and the highest antioxidant activity for both the performed assays (ORAC 8027.5±378.6μmol TE/100g fruit and PSC 2342.5±48.1μmol AAE/100g fruit). Gabiroba fruit and the pulp of guapeva had the highest antiproliferative capacity with the lowest EC50 40.7±4.8mg/mL and 37.9±2.2mg/mL, respectively. The results for the analyzed fruits for CAA were not significantly different from each other (p<0.05) (murici 41.3±17.8; gabiroba 33.9±18.8 and the pulp of guapeva 23.3±4.2μmol quercetin/100g fruit). More than 30 phenolic compounds in the pulp of guapeva, gabiroba and murici extracts were identified in the present study using ESI–TOF-MS. These results characterized for the first time the functional activity of selected Brazilian fruits and demonstrated the importance of these fruits from cerrado biome. [ABSTRACT FROM AUTHOR]