Effect of frying on the rheological and chemical properties of palm oil and its blends.
The aim of this research was to determine the changes in the physicochemical properties of palm oil and its blends by FTIR and rheological measurements. Application of heat produces some chemical compounds as impurities and even toxic compounds in oils and fats that give absorbance at different region. FTIR spectra of pure palm olein shows an absorbance at 3002 cm(-1) whereas other pure oils show maximum absorption at around 3007 cm(-1) due to C-H stretching vibration of cis-double bond (=C-H). By blending of high unsaturated oils with palm olein, a clear shift of 3007 cm(-1) band to 3005 cm(-1) occurs. Viscosity of palm olein was found higher among all oils while it subsequently and substantially reduced by blending with other oils. Since it is a function of temperature, viscosity of pure oils and their blends decreases with the increase of temperature. The loss modulus (G''), for all oil blends before and after frying, in rheological experiment was found higher for all oils than the storage modulus (G'), therefore, the viscous property was found higher than elastic property of oils and blends. However, the critical stress for all oil blends was found higher than that of pure oils.
School of Industrial Technology, Universiti Sains Malaysia, Pulau Penang, 11800 Minden Malaysia ; Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Skudai, 81300 Johor Malaysia.
Bazlul Mobin
BM
Siddique
Faculty of Chemical Engineering, Universiti Teknologi Malaysia, Skudai, 81300 Johor Malaysia.
Ida Idayu
II
Muhamad
Analytical & Environmental Chemistry Division, Department of Chemistry, Aligarh Muslim University, Aligarh, 202002 India.
Anees
A
Ahmad
School of Environmental Science, Universiti Malaysia Perlis, Jejawi, 6200 Perlis Malaysia.
Afizah
A
Ayob
School of Industrial Technology, Universiti Sains Malaysia, Pulau Penang, 11800 Minden Malaysia.
Mahamad Hakimi
MH
Ibrahim
School of Industrial Technology, Universiti Sains Malaysia, Pulau Penang, 11800 Minden Malaysia.
Mohd Omar
MO
Ak
FTIR; Oil blends; Palm olein; Rheology