Analysis of Trans Fat in Edible Oils with Cooking Process

Abstract

Trans fat is a unsaturated fatty acid with trans configuration and separated double bonds. Analytical methods have been introduced to analyze trans fat content in foods including infrared (IR) spectroscopy, gas chromatography (GC), Fourier transform-infrared (FT-IR) spectroscopy, reverses-phase silver ion high performance liquid chromatography, and silver nitrate thin layer chromatography. Currently, FT-IR spectroscopy and GC are mostly used methods. Trans fat content in 6 vegetable oils were analyzed and processing effects including baking, stir-frying, pan-frying, and frying on the formation of trans fat in corn oil was evaluated by GC. Among tested vegetable oils, corn oil has 0.25 g trans fat/100 g, whereas other oils including rapeseed, soybean, olive, perilla, and sesame oils did not have detectable amount of trans fat content. Among cooking methods, stir-frying increased trans fat in corn oil whereas baking, pan-frying, and frying procedures did not make changes in trans fat content compared to untreated corn oils. However, the trans fat content was so low and food label can be declared as ‘0’ trans based on the regulation of Ministry of Food ad Drug Safety (MFDS) (< 2 g/100 g edible oil).

The Influence of Different Fat Sources on Steatohepatitis and Fibrosis Development in the Western Diet Mouse Model of Non-alcoholic Steatohepatitis (NASH)

“…These findings fit perfectly to previous human studies showing that consuming of trans fats increase the risk of coronary artery disease by raising levels of low-density lipoprotein, lowering levels of high-density lipoproteins, and further increasing total amount of triglycerides, thereby promoting inflammation, oxidative stress and lipoperoxidation (Hadj Ahmed et al, 2018). Contrarily, typical corn oils contain only 0.25 g trans fat/100 g (Song et al, 2015) and are therefore less toxic and better for the overall metabolic situation.…”

Olive oil from the 79 A.D. Vesuvius eruption stored at the Naples National Archaeological Museum (Italy)

“…Elaidic acid (C18:1, n -9 t ), not detected in fresh olive oil, is formed by heat-induced isomerization of the native cis -monoene (oleic acid). Very prolonged storage of vegetable oils at room temperature should not cause cis / trans isomerization, which is, instead, observed in heated, fried, and refined (at 180–250 °C) oils 22 . Thus the occurrence of elaidic acid at a level comparable to that of residual oleic acid could be the result of the thermal shock that the oil underwent during the eruption.…”

“…The disappearance of the characteristic olefinic C=C stretch absorption (3004 cm −1 ) in Mann-S1 proved the almost complete saturation of the double bonds in the aliphatic chains of FAs. Trans double bonds exhibit diagnostic bands in the FTIR spectra of oils centered at 967 cm −1 22 . In this case, it was not possible to evidence the distribution of double bonds between the geometrical isomers, due to a low relative abundance of olefinic groups.…”

Application of β‐cyclodextrin, chitosan, and collagen on the stability of tocopherols and the oxidative stability in heated oils

“…Each peak of fatty acid was quantified using an equivalent concentration of the internal standard. Samples were separately analyzed in triplicates .…”