Antioxidantes

Intakes of antioxidants in coffee, wine, and vegetables are correlated with plasma carotenoids in humans.
Svilaas A; Sakhi AK; Andersen LF; Svilaas T; Ström EC; Jacobs DR; Ose L; Blomhoff R; Lipid Clinic, Medical Department, Rikshospitalet, University of Oslo, Oslo, Norway.

Fuente:
J Nutr;134(3):562-7, 2004 Mar.

Resumen: The consumption of fruits and vegetables reduces the risk of major chronic degenerative diseases. The active compounds and the mechanisms involved in this protective effect have not been well defined. The objective of this study was to determine the contribution of various food groups to total antioxidant intake, and to assess the correlations of the total antioxidant intake from various food groups with plasma antioxidants. We collected 7-d weighed dietary records in a group of 61 adults with corresponding plasma samples, and used data from a nationwide survey of 2672 Norwegian adults based on an extensive FFQ. The total intake of antioxidants was approximately 17 mmol/d with beta-carotene, alpha-tocopherol, and vitamin C contributing <10%. The intake of coffee contributed approximately 11.1 mmol, followed by fruits (1.8 mmol), tea (1.4 mmol), wine (0.8 mmol), cereals (i.e., all grain containing foods; 0.8 mmol), and vegetables (0.4 mmol). The intake of total antioxidants was significantly correlated with plasma lutein, zeaxanthin, and lycopene. Among individual food groups, coffee, wine, and vegetables were significantly correlated with dietary zeaxanthin, beta-carotene, and alpha-carotene. These data agree with the hypothesis that dietary antioxidants other than the well-known antioxidants contribute to our antioxidant defense. Surprisingly, the single greatest contributor to the total antioxidant intake was coffee.

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Effect of roasting on the antioxidant activity of coffee brews

Del Castillo MD; Ames JM; Gordon MH; School of Food Biosciences, The University of Reading, Whiteknights, Reading RG6 6AP, United Kingdom. l.delcastillo@reading.ac.uk

Fuente: J Agric Food Chem;50(13):3698-703, 2002 Jun 19.
Resumen: Colombian Arabica coffee beans were roasted to give light, medium, and dark samples. Their aqueous extracts were analyzed by gel filtration chromatography, UV-visible spectrophotometry, capillary electrophoresis, and the ABTS(*)(+) assay. A progressive decrease in antioxidant activity (associated mainly with chlorogenic acids in the green beans) with degree of roasting was observed with the simultaneous generation of high (HMM) and low molecular mass (LMM) compounds possessing antioxidant activity. Maximum antioxidant activity was observed for the medium-roasted coffee; the dark coffee had a lower antioxidant activity despite the increase in color. Analysis of the gel filtration chromatography fractions showed that the LMM fraction made a greater contribution to total antioxidant activity than the HMM components.

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