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Grapes and raisins provide phenolic antioxidants, which contribute to their potential health benefits. The objectives of this study were to compare the antioxidant capacity and phenolic content of green Thompson seedless grapes (the most common variety of grapes consumed in the United States), sun-dried raisins, and golden raisins (both produced from Thompson seedless grapes) and to observe the effects of their consumption over 4 weeks in 15 healthy human males with a cross-over design. The oxygen radical absorbance capacity (ORAC) (positive statistical significance for grapes after 2 weeks and golden raisins after 3 weeks), serum oxidation (positive statistical significance for golden raisin lag time after 4 weeks), total phenolics (no significant effects), and C-reactive protein (no significant effects) were monitored. Immediately postconsumption, there were some significant nonpositive changes. It is hypothesized that these negative results may be explained by postprandial oxidation, a known effect after carbohydrate consumption. Golden raisins had the highest antioxidant capacity and phenolic content. The consumption of a serving of grapes or raisins each day, in addition to a typical diet, may not be sufficient to overcome postprandial oxidation when consumed with other high carbohydrate foods but may have beneficial antioxidant effects over time.

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The promotional effect of sodium on Pt/Al 2 O 3 catalysts for the water-gas shift (WGS) reaction was investigated with operando FTIR during steady-state and isotopic transient experiments. The highest turnover frequency (TOF) promotion per surface Pt occurred on a 0.82 wt.% Pt/Al 2 O 3 catalyst with a 30:1 molar ratio of Na:Pt. This catalyst exhibited a TOF of 0.35 s-1 at 250 °C and 7% CO, 11% H 2 O, 9% CO 2 , 37% H 2 compared to 0.43 × 10-2 s-1 on Pt/Al 2 O 3. Operando IR revealed that Na addition modifies CO adsorption on Pt to create more strongly bound, multiplybonded CO species at 1768 cm-1 and 1697 cm-1 compared to predominantly linear CO on Na-free Pt/Al 2 O 3 at 2060 cm-1. Transient experiments with 12 CO/ 13 CO isotope switches showed that the number of carbon-containing active intermediates increased from less than 1% of the surface Pt for Na-free Pt/Al 2 O 3 to nearly 100% of the surface Pt for 20Na:Pt/Al 2 O 3 , which indicates that only a small fraction of the Pt surface on the Na-free samples participates in the WGS reaction. From time-resolved IR spectra during transient WGS with 12 CO/ 13 CO and 12 CO 2 / 13 CO 2 isotope switches, we propose that surface formate species are spectators for all Na-promoted Pt/Al 2 O 3 catalysts under these WGS conditions. The results suggest that Na promotes Pt/Al 2 O 3 for WGS by modifying the local electronic properties of Pt and creating new H 2 O activation sites, which provides greater availability of surface OH/H species to react with nearly all CO on the metallic Pt surface through a non-formate pathway.