Bioactive compounds and the antioxidant capacities of seed oils from pomegranate (Punica granatum L.) and bitter gourd (Momordica charantia L.)

Abstract Pomegranate and bitter gourd are two of the few edible fruits that contain conjugated α-linolenic acids (CLnAs) in their seeds. The CLnAs have been associated with many effects that are beneficial to health, such as antioxidant and anti-inflammatory properties. Samples of cold-pressed oils from pomegranate and bitter gourd seeds were evaluated for their phytochemical compositions (fatty acids, tocopherols and phytosterols), their qualities and their stability parameters. The in vitro antioxidant capacities of these oils were evaluated by β-carotene bleaching, DPPH• scavenging, oxygen radical absorbance capacity (ORAC) and ABTS• scavenging assays. Several differences in the compositions of the fatty acids, the bioactive compounds and the antioxidant capacities were observed for the two seed oils (pomegranate and bitter gourd) when they were assessed. The highest contents for the phytochemicals (conjugated α-linolenic acids, β-sitosterols, γ-tocopherols) and the in vitro antioxidant capacities were found in the pomegranate seed oil, when using both the DPPH• and ABTS• methods. These results have indicated that seed oils with bioactivity properties can be a challenge for more research, in order to address absorption, health benefits and technological applications.