Trans fat content in edible oils commercially available in ...
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Trans fat content in edible oils commercially available in Romania O Mărincaș 1 , I Feher 1 , V C Floare-Avram 1 and F D Covaciu 1 1 National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania E-mail: [email protected] INCDTIM Acknowledgments: The financial support for this work was provided by the PN-III-P2-2.1-PED- 2019-3502 Program, Project number 354PED/2020 RESULTS AND DISCUSSION Grape oils INTRODUCTION Trans fatty acids are formed industrially through partial hydrogenation of unsaturated fatty acids in vegetable and marine oils. The purpose of this hydrogenation is to produce fats with improved oxidative and thermal stability as well as modified physical properties. During industrial hydrogenation of the vegetable oils, apart from getting converted into saturated derivatives, some of the unsaturated fatty acids are also converted into trans isomeric forms. The profiles of trans fat from commercially available oils and natural resources are not the same. This study describes an analytical method developed for the separation, identification and quantitation of trans isomers of unsaturated fatty acids. The fatty acid composition is determined as the methyl esters of fatty acids by GC–FID. This method is applicable to a wide variety of food matrices, with particularly emphasized analysis of trans unsaturated fatty acids in oils. MATERIALS AND METHODS OIL SAMPLES: Sunflower, olive, pumpkin, walnut, flax, sesame, hemp, rapeseed, sea buckthorn, corn, grape, poppy, almond, coconut, avocado and macadamia FATTY ACIDS DERIVATIZATION Step 1). Saponification / hydrolysis of fats ❑ The oil samples (0.05 ml) are saponified by treatment with 1 ml 0.5 M KOH solution in absolute methyl alcohol at 100 C for 5 minutes in closed vials Step 2). Esterification / methylation of fatty acids ❑ Fatty acids released after saponification were then esterified by treating samples with 2 ml of 4 M HCl solution in anhydrous methanol at 100 C for 15 minutes in closed vials GC-FID ANALYSIS Column: DB-Fatwax, 30m x 0.32 mm ID, 0.25 μm Oven: 50 C (2 min), to 220 C at 4 C/min (temperature maintained for 15 min) Temperature (Injector): 250 C Temperature (Detector): 260 C Carrier: Helium, 1ml/min Corn oils Pumpkin oils Hemp oils Seabuckthorn oils Olive oils Avocado oils Macadamia oils Poppy oils Flax oils Sunflower oils Walnut oils Almond oils Rapeseed oils Sesame oils Coconut oils Peak List: C16:0 – Palmitic Acid C18:0 – Stearic Acid C18:1 – Oleic Acid C18:2 – Linoleic Acid C18:3 – -Linolenic Acid C18:3 – -Linolenic Acid C20:0 – Arachidic Acid C22:0 – Behenic Acid Hydrogenated (trans) fat formation
Transcript of Trans fat content in edible oils commercially available in ...
Trans fat content in edible oils commercially available in Romania
O Mărincaș 1, I Feher 1, V C Floare-Avram 1 and F D Covaciu 1
1 National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca, Romania
E-mail: [email protected]
INCDTIM
Acknowledgments:The financial support for
this work was provided by the PN-III-P2-2.1-PED-2019-3502 Program,
Project number 354PED/2020
RESULTS AND DISCUSSION
Grape oils
INTRODUCTIONTrans fatty acids are formed industrially through partial hydrogenation of unsaturated fatty acids in vegetable and marine oils. The purpose of thishydrogenation is to produce fats with improved oxidative and thermal stability as well as modified physical properties. During industrial hydrogenation ofthe vegetable oils, apart from getting converted into saturated derivatives, some of the unsaturated fatty acids are also converted into trans isomeric forms.The profiles of trans fat from commercially available oils and natural resources are not the same. This study describes an analytical method developed forthe separation, identification and quantitation of trans isomers of unsaturated fatty acids. The fatty acid composition is determined as the methyl esters offatty acids by GC–FID. This method is applicable to a wide variety of food matrices, with particularly emphasized analysis of trans unsaturated fatty acids inoils.
MATERIALS AND METHODSOIL SAMPLES: Sunflower, olive, pumpkin, walnut, flax, sesame, hemp, rapeseed, sea buckthorn, corn, grape, poppy, almond, coconut, avocado andmacadamia
FATTY ACIDS DERIVATIZATIONStep 1). Saponification / hydrolysis of fats❑ The oil samples (0.05 ml) are saponified by treatment with 1 ml 0.5 M KOH solution in absolute methyl alcohol at 100 C for 5 minutes in closed vials
Step 2). Esterification / methylation of fatty acids❑ Fatty acids released after saponification were then esterified by treating samples with 2 ml of 4 M HCl solution in anhydrous methanol at 100 C for 15minutes in closed vials
GC-FID ANALYSISColumn: DB-Fatwax, 30m x 0.32 mm ID, 0.25 μmOven: 50 C (2 min), to 220 C at 4 C/min (temperature maintained for 15 min)Temperature (Injector): 250 CTemperature (Detector): 260 CCarrier: Helium, 1ml/min
Corn oils
Pumpkin oilsHemp oilsSeabuckthorn oils
Olive oils
Avocado oils
Macadamia oils
Poppy oilsFlax oils
Sunflower oils
Walnut oils
Almond oils
Rapeseed oilsSesame oilsCoconut oils
Peak List:C16:0 – Palmitic AcidC18:0 – Stearic AcidC18:1 – Oleic AcidC18:2 – Linoleic AcidC18:3 – -Linolenic AcidC18:3 – -Linolenic AcidC20:0 – Arachidic AcidC22:0 – Behenic Acid
Hydrogenated (trans) fat formation
