Chemical characterization of Echium plantagineum seed oil obtained by three methods of extraction

Abstract

Echium seed oil has been considered an important alternative source of omega 3 fatty acids (n-3 FA) for human consumption. Considering the oxidative instability of n-3 FA richer oils, the objective of this study was to determine the chemical and sensory parameters of the oil obtained from Echium plantagineum seeds obtained by three extraction methods (hydraulic press: HYD; continuous screw press: PRESS; and solvent technique: SOLV). Stearidonic acid (C18:4, n3), the most important n-3 FA present in the oil, changed from 12.5% to 12.7%. Regarding the minor compounds, PRESS sample showed the highest concentration of gamma-tocopherol (782.24 mg/kg oil), while SOLV samples presented the highest amount of β-sitosterol (73.46 mg/100 g) with no difference of campesterol concentration (159.56 mg/100 g) among the samples. Higher values of total phenolics (19.65 mg GAE/kg oil) and β-carotene (34.83 mg/kg oil) were also found in the SOLV samples, suggesting the influence of hexane in the extraction of these bioactive compounds. High resolution mass spectrometry identified caffeic acid and its derivatives as the main phenolic compounds present in the echium oil. PRESS sample showed the best oxidative stability as measured by PV (0.61 mmol/kg oil) and malondialdehyde (173.13 µmol), probably due to faster time of processing compared to HYD and SOLV samples. Our data showed that the extraction method changed the chemical composition of the minor compounds in the echium oil, but these alterations did not reduce its nutritional quality or sensory acceptability.

Fatty acid profile, sterols, and squalene content comparison between two conventional (olive oil and linseed oil) and three non‐conventional vegetable oils (echium oil, hempseed oil, and moringa oil)

“…Carlini et al. (2021) found only campesterol and sitosterol in their samples, with campesterol as the most abundant one. More data from other different species of echium ( Echium vulgare L.) reported by Nogala‐Kalucka et al.…”

“…Important amounts of sitosterol (153.41 mg/100 g oil) and Δ5‐avenasterol (73.55 mg) were also found. Due to the scarce literature available about the sterol composition of echium oil, the results obtained in this study could be directly compared with two studies where different extraction methods were applied to E. plantagineum seeds (Carlini et al., 2021; Rincón‐Cervera et al., 2020). Rincón‐Cervera et al.…”

“…The third sterol identified was stigmasterol in lower concentrations. Carlini et al (2021) found only campesterol and sitosterol in their samples, with campesterol as the most abundant one. More data from other different species of echium (Echium vulgare L.) reported by Nogala-Kalucka et al ( 2010) and Minkowski et al (2010) suggest important amounts of phytosterols ranging from 424.9 to 720 mg/100 g oil, and also identifying campesterol as the predominant compound.…”

“…FDA approved its use as dietary ingredient in 2002 (FDA, 2021a), whereas the EU classified it as novel food in 2008 (Decision 2008/558/EC) (European Commission, 2008), allowing its addition into different types of foods. It is becoming a relevant alternative source of omega‐3 FAs, but its oxidative stability is yet to be explored, as well as its chemical composition in terms of the presence of minor compounds (Carlini et al., 2021).…”

Comparison of quality and oxidative stability of pumpkin seed (Cucurbita maxima) oil between conventional and enzymatic extraction methods

“…Tocopherol and phenolics are important antioxidants in oil, which contribute to the oxidative stability of oil to maintain oil quality and extend shelf life. 4,49 Table 3 shows the tocopherol content and total phenolic content (TPC) in the obtained pumpkin seed oil. In terms of tocopherol, the representative of tocopherol in pumpkin seed oil was g-tocopherol (53.1-72.3 mg/100 g), while a-tocopherol and d-tocopherol were not detected in this study.…”