THERMAL STABILITY OF VIRGIN COCONUT OIL OBTAINED FROM TWO CULTIVARS GROWN IN GUERRERO, MEXICO

Abstract

The interest in virgin coconut oil has grown in recent years due to its beneficial effects on health and its attractive physicochemical and sensorial characteristics for the consumer. In this study, the thermal stability of virgin oil coconut oil extracted from two cultivars grown in the state of Guerrero, Mexico was evaluated. The results were compared with a commercial virgin coconut oil. The studied oils showed a similar composition of fatty acids. The change in the content of free fatty acids, phenols and total flavonoids, color, infrared spectrum and values of the K₂₃₂ and K₂₇₀ extinction coefficients of the oils stored for 5 d at 80, 100 and 120 ºC in a forced convection oven were determined. The content of total phenolic compounds for commercial virgin coconut oil (CVCO), virgin oil produced from the Mapan Hybrid coconut palm (VOMHC) and virgin oil from Alto del Pacifico coconut palm (VOAPC) was 3.00 ± 0.30, 60.04 ± 4.10 and 78.00 ± 6.20 mg equivalents of gallic acid 100 g^-1 oil, respectively. The VOMHC and VOAPC of Guerrero, Mexico showed significantly greater oxidative stability than the CVCO (P ≤ 0.05). The above was concluded as no important changes were observed in the value of peroxide index, percentage of fatty acids, K₂₃₂ and K₂₇₀ extinction coefficients and hue angle. The presence of oxidized compounds after storage was demonstrated with infrared spectroscopy through the changes in frequencies 1746 and 3470 cm^-1 corresponding to the presence of carbonyl compounds and hydroperoxides, respectively. The results obtained in this study indicate that artisanal coconut oils made in Guerrero, Mexico have a greater technological potential due to their high content of phenolic compounds and greater oxidative stability compared to commercial coconut oil.