Quality characteristics of field muskmelon seed oil extracted by different processes

Abstract

Field muskmelon seeds contain plenty of oil. However, its potential as vegetable food oil has not been explored comprehensively. This study used three different processes, cold extrusion (CE), coasting followed by cold extrusion (R-CE), and supercritical fluid extraction (SFE), for the extraction of field muskmelon seed oil (FMSO) and studied its quality characteristics such as color, fatty acid composition, and volatile components. The study found that FMSO is abundant in unsaturated fatty acids (UFA) and has a pleasant aroma. Gas chromatography-mass spectrometry (GC-MS) revealed that FMSO contains five main fatty acids, palmitic (11.85 ± 0.03 to12.52 ± 0.03%), linoleic (60.94 ± 1.31 to 64.78 ± 0.77%), oleic (16.64 ± 0.26 to 18.95 ± 0.47%), elaidic (0.85 ± 0.05 to 1.06 ± 0.03%), and stearic (5.67 ± 0.03 to 8.44 ± 0.06%) acids. The relative content of fatty acids showed significant variation depending on the extraction process (P < 0.05). Furthermore, volatile components were obtained by headspace solid-phase microextraction (HS-SPME) and analyzed by GC-MS. In total, 42, 53, and 91 volatile components were identified in FMSO extracted by CE, R-CE, and SFE, respectively. R-CE extraction promoted pyrazines content (51.51 ± 3.15%) and reduced esters and acids, while SFE extraction promoted the contents of hydrocarbons (26.00 ± 2.10%) and aldehydes (26.00 ± 2.78%). Meanwhile, the contents of esters (13.43±0.6%), alcohols (12.81 ± 0.16%), and acids (11.41 ± 0.23%) were higher in CE extracted FMSO than that extracted by R-CE and SFE. These results suggest that FMSO with high UFA content and pleasant aroma could be a potential source of vegetable food oil.

Keywords:
field muskmelon seed oil; FMSO; fatty acid composition; volatile components; cold extrusion; supercritical fluid extraction; headspace solid-phase microextraction