A kind of detection method of trans fatty acid in food

Abstract

The invention discloses a method for detecting trans-fatty acid in foods. The method includes carrying out reflux extraction by the aid of ethyl alcohol-petroleum ether mixed liquid to obtain grease; refrigerating the grease at the low temperatures and then centrifuging the grease to obtain liquid-state grease and solid-state grease; mixing silver nitrate solution with the mass concentration of 2.2% and activated 300-mesh silica gel with each other to obtain mixtures, filling 2 / 3 of the volume of a chromatographic column with the mixtures, adding the liquid-state grease with the volume equal to the volume of the column into the chromatographic column, carrying out chromatography, collecting grease which flows out at first and combining the grease with the solid-state grease to obtain a trans-fatty acid crude product; adding the trans-fatty acid crude product into potassium hydroxide-methanol mixed liquid, carrying out heating reflux to obtain mixed liquid, cooling the mixed liquid, adding the mixed liquid into saturated sodium chloride solution, centrifuging the mixed liquid and the saturated sodium chloride solution and reserving supernatant; adding n-hexane into the supernatant, allowing the supernatant to stand still, dehydrating supernatant liquid and carrying out gas chromatographic analysis. The method has the advantages that different types of trans-fatty acid with components from low carbon chains to high carbon chains can be completely separated from one another and can be simultaneously measured, and accordingly the method is applicable to qualitatively and quantitatively detecting the varieties and the contents of the trans-fatty acid in common cooking oil and processed products with the cooking oil.

Description

technical field [0001] The invention relates to the technical field of food detection, in particular to a method for detecting trans fatty acids in food. Background technique [0002] The standard methods for the determination of trans fatty acids in food mainly include gas chromatography and infrared spectroscopy. Gas chromatography is to measure the content of each trans fatty acid component first, and then calculate the total trans fatty acid content by summing up and summing up. Fatty acid (methyl ester) standards and special fatty acid analysis capillary gas chromatography column, the determination and calculation process is complex. Infrared spectroscopy can directly measure the total content of trans fatty acids in food, but cannot perform qualitative and quantitative analysis on the type and content of trans fatty acids in food. [0003] Recently, the whole society has paid close attention to trans fatty acids, but my country has not yet formulated corresponding li...

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Problems solved by technology

[0003] Recently, the whole society has paid close attention to trans fatty acids, but my country has not yet formulated corresponding limit standards, which poses new issues for my country's food production and processing enterprises, sales and distribution links, and government regulatory decision-making departments. Determination methods are urgently needed