Showing papers by "Mauro Serafini published in 2003"

Total Antioxidant Capacity of Plant Foods, Beverages and Oils Consumed in Italy Assessed by Three Different In Vitro Assays

Abstract: Epidemiologic studies have demonstrated an inverse association between consumption of fruits and vegetables and morbidity and mortality from degenerative diseases. The antioxidant content of fruits and vegetables may contribute to the protection they offer from disease. Because plant foods contain many different classes and types of antioxidants, knowledge of their total antioxidant capacity (TAC), which is the cumulative capacity of food components to scavenge free radicals, would be useful for epidemiologic purposes. To accomplish this, a variety of foods commonly consumed in Italy, including 34 vegetables, 30 fruits, 34 beverages and 6 vegetable oils, were analyzed using three different assays, i.e., Trolox equivalent antioxidant capacity (TEAC), total radical-trapping antioxidant parameter (TRAP) and ferric reducing-antioxidant power (FRAP). These assays, based on different chemical mechanisms, were selected to take into account the wide variety and range of action of antioxidant compounds present in actual foods. Among vegetables, spinach had the highest antioxidant capacity in the TEAC and FRAP assays followed by peppers, whereas asparagus had the greatest antioxidant capacity in the TRAP assay. Among fruits, the highest antioxidant activities were found in berries (i.e., blackberry, redcurrant and raspberry) regardless of the assay used. Among beverages, coffee had the greatest TAC, regardless of the method of preparation or analysis, followed by citrus juices, which exhibited the highest value among soft beverages. Finally, of the oils, soybean oil had the highest antioxidant capacity, followed by extra virgin olive oil, whereas peanut oil was less effective. Such data, coupled with an appropriate questionnaire to estimate antioxidant intake, will allow the investigation of the relation between dietary antioxidants and oxidative stress-induced diseases.

Plasma antioxidants from chocolate

Abstract: Dark chocolate may offer its consumers health benefits the milk variety cannot match. There is some speculation that dietary flavonoids from chocolate, in particular (−)epicatechin, may promote cardiovascular health as a result of direct antioxidant effects or through antithrombotic mechanisms1,2,3. Here we show that consumption of plain, dark chocolate (Fig. 1) results in an increase in both the total antioxidant capacity and the (−)epicatechin content of blood plasma, but that these effects are markedly reduced when the chocolate is consumed with milk or if milk is incorporated as milk chocolate. Our findings indicate that milk may interfere with the absorption of antioxidants from chocolate in vivo and may therefore negate the potential health benefits that can be derived from eating moderate amounts of dark chocolate.

Rapid fluorimetric method to detect total plasma malondialdehyde with mild derivatization conditions

Abstract: Malondialdehyde (MDA), an oxidation product of polyunsaturated fatty acids, is used as an in vivo marker to assess lipid peroxidation in diseases such as atherosclerosis and diabetes (1)(2)(3)(4) In biological matrixes, MDA is measured after derivatization with thiobarbituric acid (TBA) (5) Because TBA reacts with many other aldehydes (6), results are expressed as TBA-reactive substances (TBARS) Several problems are associated with TBARS analysis, in particular, low reproducibility and a lack of specificity that leads to overestimations To overcome these difficulties, more specific methods have been proposed that require sample pretreatment to precipitate proteins and extract MDA-reactant adducts (6)(7)(8)(9) This additional step is time-consuming and adversely affects precision The aim of the present study was to develop a rapid and sensitive method to measure MDA in plasma, avoiding sample pretreatment Tetraethoxypropane (TEP), TBA, and bilirubin were obtained from Fluka Fatty acid-free bovine serum albumin (BSA), Total Protein Reagent, and Protein Standard were from Sigma, and 2,2′-azobis(2-amidinopropane) (ABAP) was from Wako We prepared an aqueous stock solution of 1 mmol/L TEP A 10 μmol/L MDA solution was obtained by diluting TEP in 01 mol/L HCl A 0025 mol/L TBA solution was prepared daily by dissolving TBA in water BSA solutions were prepared in 01 mol/L HCl To remove protein-bound MDA, BSA solutions were heated at 80 °C for 1 h and dialyzed for 3 days against 01 mol/L HCl in a 3500-Da cutoff dialysis membrane (Spectrapore; Spectrum Medical Industries) The actual protein concentration was verified using the Total Protein Reagent Kit A 50 mmol/L ABAP solution was prepared in water Six MDA solutions ranging from 005 to 05 μmol/L were prepared by diluting the 10 μmol/L stock solution with 01 mol/L HCl Triplicate solutions were used to obtain a dose–response …

Nutrition: Milk and absorption of dietary flavanols

Abstract: Our results indicate that there is an increase in total antioxidant capacity (TAC) and (–)epicatechin content of plasma in people who have consumed dark chocolate, and that these effects are reduced by the presence of milk1. Halliwell and Schroeter et al. raise issues that are central to the debate over the fate and potential protective effects of dietary antioxidants.

Health promoting effect of fruit and vegetables consumption: Mechanism of action in humans

Abstract: Summary In vivo 02 utili zation fo r cataboli c processes is associated with the generation of Reac ti ve Oxygen Species (ROS). Excessive production of ROS can cause Oxidative Stress, wh ich is the unbalance between ROS and antioxidant defenses. ROS, by causing oxidative damage to biologica! macromo­ lecul es such as DNA, lipids, carbohydrates and proteins, are believed to be involved in the initiation and progression of severa! chronic di seases, including coronary heart disease (CHD) and cancer. Oxidative stress can be modulated by the diet, epidemiologica! research has shown an in ve rse rela­ tionship between fruit and vegetable consumption and the incidence of degenerative diseases. The most plausible explanation for thi s association is that foods of plant origin, through their high con­ tent in antioxidant compounds, could reduce oxid ative stress and, therefore, prevent oxidative dama­ ge to macromolecules. Antioxidant supplementation trial s, although not conclusive on this regard, have leading to contrasting results, highlighting the fact that other compounds have to play a role in the health effects of plant food. The scientific community has recently put new hopes in the prece­ ding hypothesis by identifying a class of compounds wid ely present in plant foods endowed with a strong antioxidant activity: the phenolic compounds. This paper aims to summarize the health-promoting benefits of fruit and vegetable consumption with special focus on the most recently suggested role played by phenolic compounds in decreasing the risk of degenerative diseases.