A new computational approach for the determination of 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity (DPPH-RSA) in food is reported, based on the concept of machine learning. Trolox standard was mix with DPPH at different concentrations to produce different colors from purple to yellow. Artificial neural network (ANN) was trained on a typical set of images of the DPPH radical re...

Seasonal discrepancy in the antioxidant potential from bark of Nothapodytes nimmoniana was evaluated using two different methods (DPPH and FRAP) and were related to total phenolic content as well as flavonoid content. Higher yield of phenolic and flavonoid were observed during summer (May) similarly, the antioxidant activities (DPPH & FRAP) also were high. The antioxidant activities were strong...

The free radical 2,2-diphenyl-1-pycrylhydrazyl (DPPH) was tested as a polarising agent for fast dissolution dynamic nuclear polarisation (DNP) NMR spectroscopy. DPPH was found to be reasonably soluble in sulfolane and the optimum concentration for DNP is 20-40 mM depending upon whether short polarisation times or the maximum signal intensity is needed. W-band ESR measurements revealed that the ...

Approaching living systems, aqueous solutions are appropriate to characterize antioxidants, whereas the frequently used standard 1,1-diphenyl-2-picrylhydrazyl (DPPH) is insoluble in water. Therefore, mixed water-ethanol solvents were investigated using the electron paramagnetic resonance (EPR) spectroscopy. Two forms of DPPH were identified: at higher ethanol ratios a quintet spectrum character...

The reactivity of tocopherols with 2,2-diphenyl-1-picrylhydrazyl (DPPH) was studied in model systems in order to establish a method for quantifying vitamin E in plant oils. The method was optimized with respect to solvent composition of the assay medium, which has a large influence on the course of reaction of tocopherols with DPPH. The rate of reaction of α-tocopherol with DPPH is higher than ...