Chemical Assessment and Proximate Composition of Shorea macrophylla and Shorea palembanica Seed Oil and Oilseeds

Present study evaluated the fatty acid profile and oxidative stability of Shorea macrophylla and Shorea palembanica oils. Analysis on fatty acid profile of S. macrophylla and S. palembanica oils using gas chromatography mass spectrometer (GC-MS) and fourier transform infrared spectroscopy – attenuated total reflectance (FTIR-ATR) found no significant difference among the oils. Stearic, palmitic and oleic acids are the major fatty acids in Shorea oils. The influence of type of extraction, fatty acid profile, and anti-oxidant activity on acid value (AV) and peroxide value (PV) were determined using Pearson correlation coefficient (r) analysis. Highest correlation was found between type of extraction, antioxidant activity (phenolic content), AV and PV, suggesting the type of extraction strongly influenced the phenolic content and oxidative stability. S. macrophylla oil extracted using mechanical expeller (MESM) have the highest quality oil (AV: 3.76 mg NaOH/g; PV: 7.96 meq O2/kg) compared to SESM, MESP and SESP oils. Similarities in fatty acid composition and oxidative stability of Shorea oil and cocoa butter indicates the potential of Shorea oil to be utilised industrially as Cocoa Butter Equivalence (CBE) and vegetable oil. Shorea oilseeds contain an appreciable amount of essential macrominerals and a comparable amount of microminerals to common seeds. The anti-nutritive factor oxalate was found higher (p<0.05) in S. palembanica oilseeds than in S. macrophylla with values of 0.14 and 0.12 g/100 g respectively. The amount of phytate in Shorea seeds is not significantly different at 5% level with a value of 0.29 g/100 g.