The Malaysian Journal of Analytical Sciences, Vol 13 No 1 (2009): 1 - 7

 

 

 

 

A study on the thermal properties and solid fat content of Malaysian rubber seed oil

 

(Satu Kajian Sifat Terma dan Kandungan Pepejal Lemak Dalam Minyak Biji Getah Malaysia)

 

Jumat Salimon*, Bashar Mudhaffar Abdullah

 

School of Chemical Science and Food Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia

 

*Corresponding author: jumat@ukm.my

 

Abstract

This study was carried out to determine the characteristics, thermal properties and solid fat content of Malaysian rubber (Hevea brasiliensis (kunth. Muell)) seed oil (RSO). RSO was extracted using hexane and degummed using phosphoric acid. The RSO physicochemical properties such as free fatty acid (FFA %), acid value, saponification value, iodine value, and unsaponifiable matter gave values of 7.55±0.02%, 15.03±0.04, 182.12±0.27, 135.79±0.33 and 1.83±0.01 respectively. Gas chromatography (GC) was used to determine the fatty acid (FA) composition. RSO consisting of saturated FA (19.12±0.28%) such as palmitic (8.56±0.07%) and stearic (10.56±0.02%) acids and unsaturated FA (79.45±0.31%) such as oleic (22.95±0.15%), linoleic (37.28±0.10%) and linolenic (19.22±0.21%) acids. High performance liquid chromatography (HPLC) was used to determine the triacylglycerol (TAG). Polyunsaturated TAGs of LnLnL (7.7%), LnOO (7.5%), PPL (6.4%), LnLL (5.9%), OLLn (5.9%) and PPL (5.8%) were the major TAGs found in RSO.  The differential scanning calorimetry (DSC) showed that crystallized TAG was observed at -9.95°C. The melting curves displayed two major exothermic regions of RSO the unsaturated TAG at -28.87°C and the saturated TAG at -10.22°C. The solid fat content (SFC) of RSO showed low percentages of solids (0.24%, 0.13%, 0.12%, 0% and 0%) at different temperatures of 0, 5, 10, 15 and 20°C. The results of this study showed that the RSO is plausible source of polyunsaturated fatty acid (PUFA) to be developed in the future after removing the free fatty acid to make it more acceptable.

 

Keywords: Rubber seed oil; Thermal properties; Solid fat content

 

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