The Antioxidant Potential of White Wines Relies on the Chemistry of Sulfur-Containing Compounds: An Optimized DPPH Assay

Abstract

The DPPH (2,2-Diphenyl-1-picrylhydrazyl) assay is an easy and efficient method commonly used to determine the antioxidant capacity of many food matrices and beverages. In contrast with red wines, white wines are poorer in antioxidant polyphenolics, and the more hydrophilic sulfur-containing compounds in them may contribute significantly to their antioxidant capacity. The modification of the classical DPPH method, with a methanol-buffer and the measure of EC20 (quantity of sample needed to decrease the initial DPPH concentration by 20%) has shown that sulfur-containing compounds such as cysteine (0.037 ± 0.003), glutathione (0.054 ± 0.003) or methanethiol (0.104 ± 0.003) appeared to bear antioxidant capacity comparable to well known phenolic compounds, such as catechin (0.035 ± 0.003), caffeic acid (0.057 ± 0.003) and ferulic acid (0.108 ± 0.003), respectively. In the case of white wines, the comparison with REDOX-sensory scores showed that results from this modified DPPH assay are strongly correlated with sensory attributes (r = 0.73, p < 0.1). These results provide an unprecedented illustration of the important contribution of these sulfur-containing compounds to the radical quenching ability of white wines.

Can Chemical Analysis Predict Wine Aging Capacity?

“…Another study looking at antioxidant capacity versus vintage age had a different result [ 26 ], see Figure 6 . The wine samples are white wine of nine vintages from the same vineyard.…”

“…Student tests show comparison between methanol and methanol-buffer methods, “*” indicate significant difference ( p < 0.05). [ 26 ].…”

Purple to Yellow Silicone Elastomers: Design of a Versatile Sensor for Screening Antioxidant Activity

“…The DPPH silicone sensor was also used to evaluate the antioxidant activity of unmodified food or beverage samples that are known to possess antioxidant properties . Response curves of the sensor to the samples ( Figure b) were measured with a spectrophotometer by using a 24‐microwell plate coated with DPPH silicone, as discussed in the previous paragraph.…”

Formulation of Creams Containing Spirulina Platensis Powder with Different Nonionic Surfactants for the Treatment of Acne Vulgaris

“…DPPH reacted with antioxidant compounds, which can donate hydrogen. When DPPH accepted hydrogen radical the reaction resulted in a color change from deep purple to light yellow [ 77 ]. Quantitative measurement of the remaining DPPH was carried out with UV-spectrophotometer (Shimadzu Spectrophotometer, Tokyo, Japan) at 517 nm [ 78 ].…”