In vitro comparison of antioxidant capacity of cumin (Cuminum cyminum L.) oils extracted and purified by supercritical fluid extraction and molecular distillation and their main components

Abstract

The antioxidant activities (AOAs) of β‐pinene, p‐cymene, γ‐terpinene, cuminaldehyde, cumin oleoresin (COR, supercritical fluid extraction) and its molecular distillation products (CEO, DR&CT) were investigated in present study. IC50 value and kinetics rate were used to evaluate the efficiency of tested samples in scavenging the alkylperoxyl radical (AR) generated in the β‐carotene‐linoleic acid emulsion system and the 2,2‐diphenyl‐1‐picrylhydrazyl radical (DPPH·). In the kinetic approach, antioxidant efficiency was estimated at t=20 s and expressed as the rate of β‐carotene remaining (R1(β‐carotene)) and the rate of DPPH· scavenging (R2(DPPH)). Results showed that the order of AOAs of cumin oils was DR=COR >CEO >CT. Among all samples, γ‐terpinene exhibited the highest R1(β‐carotene) value and the lowest IC50 value (0.73mg/ml), which indicated the strongest response in AR scavenging in β‐carotene bleaching test. The R2(DPPH) values for DR and COR, followed by γ‐terpinene, showed the highest response in scavenging DPPH·, with IC50 values were 6.72, 8.53, 22.73mg/ml, respectively. There were good correlations between IC50 DPPH and IC50 β‐carotene (r2=0.7990), but no association could be found between R1(β‐carotene) and R2(DPPH). Our results showed that one of the active antioxidant components in cumin oils was γ–terpinene.