Chemical Composition, Anti-oxidant, and Antimicrobial Activities of Four Saline-Tolerant Plant Seed Oils Extracted by SFC

The supercritical CO 2 fluid extraction process was used to obtain seed oils. The compositional analyses of the seed oils of Amorpha fruticosa L., Caragana microphylla Lam and Elaeagnus angustifolia L. were performed by GC–MS, from which 18–22 fatty acid compositions were identified, and their main components were linoleic acid (49.10–66.39 %) and oleic acid (11.95–41.10 %). The seed oils were rich in unsaturated fatty acids, which accounted for 79.75–91.19 %. The in vitro anti-oxidant activities of the seed oils were measured by the DPPH, ABTS and phosphomolybdenum complex assays. The IC 50 s of the seed oils were 6.5110–12.6599 mg/mL tested by DPPH assay, and the IC 50 s were in the range of 0.6872–1.9310 mg/mL tested by ABTS assay. The anti-oxidant activities of seed oils decreased in the order of A. fruticosa > C. microphylla > E. angustifolia (A) > E. angustifolia (D). In vitro antimicrobial activities of seed oils against five bacteria were tested by microdilution method. The MIC values of the oils against Bacillus subtilis , E. coli , S. aureus , P. solanacearum and B. thuringiensis were in the range of 26–36, 30–38, 58, 56–58 and 56–58 mg/mL, respectively, while the MBC values were in the range of 30–40, 34–42, 58, 56–58 and 58 mg/mL, respectively. In vitro antifungal properties of the seed oils against four plant pathogenic fungi were tested by the mycelial growth rate method. The EC 50 s of seed oils against V. mali , C. gloeosporioides , F. graminearum and B. cinerea were in the range of 17.51–19.25, 15.58–19.12, 8.00–17.12 and 18.76–19.14 mg/mL, respectively. The seed oils showed moderate anti-oxidant and antimicrobial activities.