Table 1 shows the main chemical characteristics of the seven
samples used in the thermal oxidation assays, presented in
increasing order of degree of unsaturation. The three basic oils
enormously differed in their fatty acid composition. The linoleic
acid content was very low for HOHPSO and HOSO (2.4% and 5.1%,
respectively), in contrast to the high content in HLSO (56.8%).
The preparation of the four binary mixtures was performed to give
increasing concentrations of linoleic acid, which is the fatty acid
most susceptible to degradation in sunflower oils. Thus, HOHPSO
and HOHPSO/HLSO 95:5 differed essentially in the content of linoleic
acid, which was double for the latter, while HOHPSO/HLSO
95:5 and HOSO, which presented the same content of linoleic acid,
only differed in the content of saturated and monounsaturated
acids. The rest of the mixtures are characterised by similar contents
of saturated acids, with varying contents of oleic and linoleic
acids. All the samples had a-tocopherol as the major natural antioxidant,
but at variable contents, ranging from 283 to 747 mg /kg.
The oil stability index (OSI) values were quite different according
to the oil composition, ranging from 4.8 to 34.4 h at 110 C. The
HOHPSO showed a remarkably high OSI value, which makes it possible
to be used as a vegetable oil of potential applications in those
processes using partially hydrogenated oils (Guinda, Dobarganes,
Ruíz-Méndez, & Mancha, 2003). Free fatty acids (lower than
0.05%) and peroxide values (lower than 3 meq O2/kg) were similar
for the three oils and the binary mixtures and typical of fresh refined
oils of good quality.
Table 1 shows the main chemical characteristics of the seven
samples used in the thermal oxidation assays, presented in
increasing order of degree of unsaturation. The three basic oils
enormously differed in their fatty acid composition. The linoleic
acid content was very low for HOHPSO and HOSO (2.4% and 5.1%,
respectively), in contrast to the high content in HLSO (56.8%).
The preparation of the four binary mixtures was performed to give
increasing concentrations of linoleic acid, which is the fatty acid
most susceptible to degradation in sunflower oils. Thus, HOHPSO
and HOHPSO/HLSO 95:5 differed essentially in the content of linoleic
acid, which was double for the latter, while HOHPSO/HLSO
95:5 and HOSO, which presented the same content of linoleic acid,
only differed in the content of saturated and monounsaturated
acids. The rest of the mixtures are characterised by similar contents
of saturated acids, with varying contents of oleic and linoleic
acids. All the samples had a-tocopherol as the major natural antioxidant,
but at variable contents, ranging from 283 to 747 mg /kg.
The oil stability index (OSI) values were quite different according
to the oil composition, ranging from 4.8 to 34.4 h at 110 C. The
HOHPSO showed a remarkably high OSI value, which makes it possible
to be used as a vegetable oil of potential applications in those
processes using partially hydrogenated oils (Guinda, Dobarganes,
Ruíz-Méndez, & Mancha, 2003). Free fatty acids (lower than
0.05%) and peroxide values (lower than 3 meq O2/kg) were similar
for the three oils and the binary mixtures and typical of fresh refined
oils of good quality.
การแปล กรุณารอสักครู่..
