Effects of the extraction of fatty acids and thermal/rheological properties of Mexican red pitaya oil

Abstract

We evaluated the effects of solvents with different polarities—methylene chloride (MC), methanol (MT), and hexane (HE) on the extraction of compounds from Mexican red pitaya seed oil. The fatty acid composition and the structural, rheological, and thermal properties of the different extracts were characterized. The results indicated that the highest yield of extraction was generated for MC (26.96%), as well as the greatest amount of Mono and Polyunsaturated fatty acids, while the lowest yield was for MT (16.86%). The antioxidant activity was greater in the MT treatment due to extractable compounds from high polarity. The generated extracts contained unsaturated fatty acids, mostly oleic and linoleic acids, and saturated fatty acids such as palmitic acid. The lowest solidification temperature was −6.35 ℃ for MC due to its fatty acid composition, and the degradation temperature was around 240 ℃. The viscosity is a quality parameter; the highest level was generated for the MC treatment, which was significantly different from HE and MT. The composition of the extracts was analyzed using the FT-IR spectroscopy and showed the typical characteristic of absorption bands for triglycerides with high frequency in bands 2852 cm−1 and 2924 cm−1, which indicated that the samples were rich in unsaturated and polyunsaturated acids. These results suggested that pitaya seed oil is an excellent alternative source of essential fatty acids with potential physiological benefits.

Keywords

• mexican red pitaya
• seed
• antioxidant
• fatty acids profile