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