The phenolic compounds, tocopherols, and phytosterols in the edible oil of guava (Psidium guava) seeds obtained by supercritical CO2 extraction

An edible oil was obtained from guava seeds by supercritical CO2 extraction. The oil was characterized by its fatty acid composition, physicochemical properties, and the contents of phenolic, miscellaneous, phytosterol, and tocopherol compounds. The oil, obtained with a yield of 8.6 +/- 1.2 g oil/100 g guava seeds, had a high content of linoleic acid (78.5 %, w/w), followed by that of oleic acid (13.8 %, w/w). The guava seed oil had physicochemical properties comparable to those published in previous research, except for the low stability to oxidation. The chromatographic profile of the phenolic and miscellaneous compounds was dominated by vanillin (9.6 +/- 0.3 mg/100 g oil) and cinnamaldehyde (9.4 +/- 0.2 mg/100 g oil), followed by vanillic acid (3.9 +/- 0.4 mg/100 g oil), cinnamic acid (2.4 +/- 0.1 mg/100 g oil), and minor amounts of other phenolic aldehydes. Among the phytosterols and tocopherols, beta-sitosterol (1048.9 +/- 48.4 mg/100 g oil) and gamma-tocopherol (82.6 +/- 3.7 mg/100 g oil) were the most abundant. The low oxidative stability of the oil compared to that published in previous reports might reflect the high complexity of this matrix. This oil might have applications, directly or after blending with more stable edible oils.