初榨橄榄油中多酚化合物的UPLC-FLD检测及其抗氧化活性研究

采用超高效液相色谱荧光检测法(UPLC-FLD)检测不同品种初榨橄榄油中6种多酚化合物的含量,并测定样品的总多酚含量及抗氧化活性,同时对多酚组分与抗氧化能力的相关性进行分析.结果表明:色谱条件为采用Cadenza色谱柱(150 mm×4.6 mm,5μm),柱温35℃,以0.1％甲酸-水(A)-乙腈(B)为流动相进行梯...

UPLC-FLD determination and antioxidant activity of polyphenols in virgin olive oil

An ultra high performance liquid chromatography (UPLC) coupled with fluorescence detector (FLD) was used to determine the contents of 6 selected phenolic compounds in different samples of virgin olive oil. The total polyphenols content and antioxidant activity of these samples were also detected. The chromatographic column used was Cadenza (150 mm×4.6 mm, 5 μm) and the mobile phase was composed of 0.1% formate-water (A) and acetonitrile (B). Column temperature was at 35℃. The excitation wavelength and emission wavelength were 278 nm and 339 nm. Under the conditions, 6 phenolic compounds in virgin olive oil could be separated well within 17 min, with a wider range of concentration, good linear relationship (R²≥ 0.999 5), high precision with the relative standard deviation (RSD) of intra-day precision≤ 4.91%, RSD of inter-day precision ≤ 5.41%, and reliable recovery with the average recovery rate of 93.42%-119.86%, RSD≤6.26%. The contents of hydroxytyrosol, tyrosol, vanillic acid, pinoresinol and total polyphenols in different virgin olive oil samples were significantly different, while the contents of oleuropein and ligstroside were the lowest and the differences between samples were relatively small. Polyphenols extracts of virgin olive oil have good antioxidant activity, but significant differences between different samples were detected. The total antioxidant capacities of the samples were from 0.95 to 2.71 mmol·L^-1 Trolox determined by ABTS method. DPPH free radical scavenging activities of samples were 7.22%-66.23%. Hydroxyl free radical clearance capabilities of samples were 13.24-136.06 U·mL^-1. Coratina showed the strongest antioxidant activity among samples. The content of total polyphenols was significantly correlated to total antioxidant capacity of the extracts of virgin olive oil.