Search

Here, we examined the phytochemical profiles, antioxidant activity (AA), and antiproliferative activity (APA) of four Chinese bayberry (Myrica rubra Sieb. et Zucc.) pulp extracts. They were found to be rich in total phenolics content (TPC; 186.45 ± 5.42 to 498.94 ± 8.25 mg of gallic acid equiv./100 g FW) and total flavonoids content (TFC; 126.28 ± 4.18 to 194.35 ± 12.03 mg of catechin equiv./100 g FW). For all varieties, the free flavonoid/phenolic/anthocyanin contents were higher than that the bound fractions. Wild pink bayberry (WPB) displayed the highest values of TPC and TFC, and also showed the highest total antioxidant activity (TAA) as revealed by peroxyl radical scavenging capacity (PSC) (451.47 ± 8.01 µmol Vit. C equiv./100 g FW), and free cellular antioxidant activity (CAA) (184.99 ± 6.11 µmol quercetin equiv./100 g FW, no PBS wash; 117.78 ± 2.34 µmol quercetin equiv./100 g FW, PBS wash) assays. Bayberry extracts had a marked reduction in the APA of HepG2 cells, and WPB exhibited the lowest EC50 (8.50 ± 0.83 mg/ml) value, which was probably associated with cell cycle arrest and apoptosis induction. Practical Application: Chinese bayberry (Myrica rubra Sieb. et Zucc.) fruit is rich in natural phenolic compounds, which might be a functional ingredient in food and nutraceutical products. Our findings would provide a logical strategy to promote the comprehensive utilization of phenolics in bayberry fruit with both health and economy benefits. [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]

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 phytochemical profiles and antioxidant activity of free, soluble-conjugated, and bound fractions of brown rice and its processed products (textured rice, cooked rice and rice noodle) were studied. Nineteen phenolic acids were identified. Trans -ferulic acid was the most abundant monomeric phenolic acid with trans-trans -8-O-4′ diferulic acid being most abundant diferulic acid. Processing increased the content of free phenolic acids, but decreased the content of soluble-conjugated phenolic acids. The content of bound phenolic acids was increased by improved extrusion cooking technology and cooking, but not affected by rice noodle extrusion. The total phenolic contents and antioxidant activities of free and soluble-conjugated fractions were decreased after processing, whereas those of bound fraction were increased by improved extrusion cooking technology and cooking, but not affected by rice noodle extrusion. Results indicated that whole foods designed for reducing chronic disease risk need to consider the effects of processing on phytochemical profiles and antioxidant activity of whole grains. [ABSTRACT FROM AUTHOR]

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]

Phytochemical profiles, antioxidant and antiproliferative activities of berry extracts were evaluated and compared in four subspecies of Sea buckthorn ( Hippophaë rhamnoides L.). Among the subspecies, Hippophaë rhamnoides L. subsp. sinensis exhibited highest total phenolics content (38.7 ± 1.3 mg GA equiv./g DW) and corresponding total antioxidant activity. Whereas maximum cellular antioxidant and antiproliferative activities were determined in Hippophaë rhamnoides L. subsp . yunnanensis . Total antioxidant activity was significantly associated to total phenolics, isorhamnetin-3-rutinoside and isorhamnetin-3-glucoside. The cellular antioxidant activity and antiproliferative activity of phytochemicals were fairly correlated to phenolic acids and flavonoid aglycones. Lower median effective dose (EC 50 ) of individual compounds against human liver cancer HepG2 cells proliferation studies confirmed the better correlation between antiproliferative activity of Sea buckthorn extracts and flavonoid aglycones, including isorhamnetin, quercetin and kaempferol. [ABSTRACT FROM AUTHOR]

Citrus is a rich source of nutritive and bioactive compounds. Impact of fruit tissues and ripening stage on phytochemical profile, antioxidant capacity and antiproliferative activity was investigated in Citrus reticulata Blanco cv. Chachiensis (Chachi). Regardless of different ripening stage, peel had the highest contents of phenolics and flavonoids, strongest antioxidant activities resolved by PSC, ORAC and CAA assay and antiproliferative activities against MCF-7, HepG2 and SiHa cancer cell. Increased level of total phenolics, hesperidin and naringin, and elevated antioxidant capacities were detected in peel during maturity, whereas highest amount of nobiletin and strongest antiproliferative activities were explored in immature peel. In flesh the vitamin C content increased during ripening, while lower phenolic content, smallest ORAC value and weakest antiproliferative activity were resolved in mature flesh. The flavonoid content and antioxidant capacity in seed were comparable with flesh and relatively constant during ripening, suggesting seeds as a valuable source of flavonoid extraction for further utilization. The characteristic flavonoids, nobiletin, tangeretin, hesperetin and naringenin inhibited proliferation of SiHa, HepG2 and MCF-7 cell dose-dependently, thus suggesting their contribution and potential application. Results presented here provide the foundation for comprehensive utilization of phytochemicals in different parts of this medicinal and edible citrus fruit. [ABSTRACT FROM AUTHOR]

Abstract: The phytochemical content and antioxidant activity of six diverse varieties of whole wheat are reported. The free phenolic content ranged from 255 (KanQueen) to 499 (Roane)μmol gallic acid equivalents/100g DW. The bound phenolic content ranged from 582 (Roane) to 662 (Cham1) μmol gallic acid equivalents/100g DW. The bound fraction contributed 53.8–69.7% of the total phenolic content of the wheat varieties analysed. Ferulic acid was the predominant phenolic acid found in whole wheat. Total ferulic acid content ranged from 310.8 (Caledonia) to 496.1 (KanQueen)μmol ferulic acid/100g DW. The percentage of ferulic acid found in the insoluble-bound fraction ranged from 87.4% (Caledonia) to 97.2% (KanQueen). Other phenolic acids, p-coumaric acid, syringic acid, vanillic acid, and caffeic acid were also detected. Lutein was the predominant carotenoid found in the whole wheat varieties analysed. Zeaxanthin, β-carotene, and β-cryptoxanthin were also detected. Mainly α- and β-tocopherols and α- and β-tocotrienols were found in all varieties of whole wheat though γ-tocopherol was detected in all but two varieties. β-Tocotrienol was the predominant form of vitamin E found in all varieties of whole wheat. The antioxidant activity was assessed using the oxygen radical absorbance capacity (ORAC) assay. The ORAC of the free fraction ranged from 1958 to 3749μmol Trolox equivalents/100g DW. The ORAC of the bound fraction ranged from 3190 to 5945μmol Trolox equivalents/100g DW. Total phenolic content was correlated with oxygen radical absorbance capacity (R 2 =0.810; p <0.001). The phytochemicals found in whole grains may be responsible for the health benefit of whole grain consumption. [Copyright &y& Elsevier]