Stability and Change in Fatty Acids Composition of Soybean, Corn, and Sunflower Oils during the Heating Process

Abstract

This work has been undertaken to investigate the effect of heat treatment on the edible oils (soybean, sunflower, and corn) used in frying and cooking, in particular on the fatty acid composition. The heating process was maintained at 150, 180, 210, and 240°C. At each temperature, the variation of the fatty acid composition was determined after 12, 24, 36, 48, and 60 h of treatment by using an improved analytical gas chromatography method. This study showed that the oils, which had undergone a temperature of 150 to 180°C, kept some thermal stability and preserved their fatty acid composition at different treatment periods. At the temperature (180°C), two new fatty acids (C8:0 and C12:0) appeared, which could be explained by the transformation of the other fatty acids during the heating process by different chemical reactions. However, the composition of the three oils was significantly affected at 210°C and 240°C. Two trans-fatty acids (C18:1 9t and C18:2tt) were generated proportionally to heat treatment during the heating process for the three oils, providing information on their oxidative state. The results showed that sunflower oil was most affected by the heating temperature than soybean and corn oil. Therefore, more attention should be paid to the heat treatment used and the heating period to preserve the quality of edible oils.

Surface Basicity and Hydrophilic Character of Coal Ash-Derived Zeolite NaP1 Modified by Fatty Acids

“…As a general tendency, supported fatty acids are more thermally stable than free molecules [ 80 , 81 , 82 , 83 ]. In addition, saturated and short chain fatty acid are the most stable below 300 °C, resulting in a decrease in thermal stability in the following sequence: lauric acid ˃ palmitic acid ˃ oleic acid [ 84 , 85 , 86 , 87 ]. Similar TPD patterns were achieved after repeated desorption–wet CO 2 re-saturation cycles, providing clear evidence of the thermal stability of the investigated samples within the range of 20–120 °C, with a consecutive stepwise thermal desorption (STD) at a constant temperature of 120 °C for 20 min.…”

Optimization of soybean pre-treatment processes for the improvement of their nutritional, biochemical and bioactive characteristics

“…This could be explained by the fact that germination is a biological process that requires a significant expenditure of energy. The carbohydrate reserves were thus converted into energy to allow the seed to germinate [27]. The contents of "major nutrients" gave energy values ranging from 381.27±8.98 KJ to 414.81±11.45 KJ.…”

Synergistic Mechanisms of Interactions between Myricetin or Taxifolin with α-Tocopherol in Oil-in-Water Emulsions

“…Soybean oil was chosen specifically because it is highly unsaturated, with a fatty acid composition of 55% linoleic acid, 22% oleic acid, and 6% linolenic acid. 21 Second, mechanisms producing synergism were evaluated by analyzing myricetin's metal chelating activity and tocopherol regeneration. The results were compared to taxifolin (3, 3′, 4′ 5, 7 pentahydroxyflavanone or dihydroquercetin), a flavonoid structurally similar to myricetin (Figure S1).…”

“…This was performed at pH 4.0 and 7.0, which are common pH values for food emulsions. Soybean oil was chosen specifically because it is highly unsaturated, with a fatty acid composition of 55% linoleic acid, 22% oleic acid, and 6% linolenic acid . Second, mechanisms producing synergism were evaluated by analyzing myricetin’s metal chelating activity and tocopherol regeneration.…”