Determination of trigonelline in seeds and vegetable oils by capillary electrophoresis as a novel marker for the detection of adulterations in olive oils.
A capillary electrophoresis method with UV detection was developed for the first time for the determination of the pyridine betaine trigonelline (N-methylnicotinic acid) in seeds and vegetable oils. Analytical characteristics of the method showed its good performance in terms of linearity (r > 0.999), precision (relative standard deviations < 5%), and limits of detection (up to 0.9 microM or 1 ng/g for oils). The developed method was applied to the analysis of soy and sunflower seeds, three varieties of olives, and sunflower, soy, and extra virgin olive oils. Trigonelline was determined in soy and sunflower seeds and their respective oils, whereas it was not detected in olives or olive oils. Different mixtures of extra virgin olive oil with seed oils were analyzed, detecting up to 10% of soy oil in olive oil. As a consequence, trigonelline is proposed in this work as a novel marker for the detection of adulterations of olive oils with other vegetable oils such as soy and sunflower oils.
Sánchez-Hernández
Laura
L
Department of Analytical Chemistry, Faculty of Chemistry, University of Alcala, Ctra. Madrid-Barcelona Km. 33.600, 28871 Alcala de Henares (Madrid), Spain.
Puchalska
Patrycja
P
García-Ruiz
Carmen
C
Crego
Antonio L
AL
Marina
Maria Luisa
ML
D000470:Alkaloids / Q000032:analysis*; D019075:Electrophoresis, Capillary / Q000379:methods*; D000069463:Olive Oil; D010938:Plant Oils / Q000032:analysis* / Q000592:standards; D011786:Quality Control; D012639:Seeds / Q000737:chemistry*
D000470:Alkaloids; D000069463:Olive Oil; D010938:Plant Oils; C009560:trigonelline