Figure 2

Detection of monoterpenes by incubation with DPPH. (A) Sample output are shown for 100 μM DPPH incubated with 0 μM (+), 100 μM (♦), 200 μM (Δ), 800 μM (□), and 1600 μM limonene (▼), with an expanded section of this data to 12.5 min shown in (B). The rates of reaction between 100 μM DPPH and varying concentrations of limonene (C), myrcene (D), γ-terpinene (E), and β-pinene (F) were calculated with a linear regression of the data collected in period of the reaction between 7–12 min (n = 3 for each concentration, mean ± 1 SD). Reaction rates for DPPH incubated with monoterpene standards were compared to the relevant negative controls using an unpaired Student’s t-test (* = p <0.05, ** = P <0.01, *** = p < 0.001).