Olive oil oxidation: Rejection points in terms of polar, conjugated diene, and carbonyl values

Paraoxonase 1 (PON1) is associated with HDL and modulates the antioxidant and anti-inflammatory role of HDL. The goals of the present study were to investigate the effect of ageing and the role of PON1 on the anti-inflammatory activity of HDL, and to determine whether extra-virgin olive oil (EVOO) consumption could improve the atheroprotective activity of HDL. HDL and PON1 were isolated from the plasma of ten young (Y-HDL and Y-PON1) and ten elderly (E-HDL and E-PON1) healthy volunteers before and after 12 weeks of EVOO consumption. Inflammation was assessed by measuring intracellular adhesion molecule 1 (ICAM-1) expression. THP-1 (human acute monocytic leukaemia cell line) monocyte chemotaxis was measured using a Boyden chamber. Oxidative damage to HDL was assessed by measuring conjugated diene formation and changes in electrophoretic migration. Y-HDL had more anti-inflammatory activity than E-HDL. The conjugated diene content and the electrophoretic mobility of E-HDL were higher than those of Y-HDL. Y-PON1 had significant anti-inflammatory activity, reducing ICAM-1 expression by 32·64 (sd 2·63) %, while E-PON1 had no significant effect. THP-1 chemotaxis measurements confirmed the ICAM-1 expression results. The 12 weeks of EVOO consumption significantly increased the anti-inflammatory activities of both HDL and PON1. The anti-inflammatory activity of HDL was modulated by PON1 and was lower in the elderly volunteers. EVOO consumption increased the anti-inflammatory effect of HDL and reduced the age-related decrease in anti-atherogenic activity.

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Effect of Oil Oxidation on Acrylamide Formation in Oil-Rich Model Systems Without the Participation of Reducing Sugars

Journal of Food Protection ◽

10.4315/0362-028x.jfp-19-353 ◽

2020 ◽

Vol 83 (2) ◽

pp. 342-349

Author(s):

XIPING NAN ◽

QIONG WU ◽

SHULI NAN ◽

XIANPENG ZENG ◽

YONGGANG DAI ◽

...

Keyword(s):

Soybean Oil ◽

Olive Oil ◽

Peroxide Value ◽

Reducing Sugars ◽

Acid Value ◽

Model System ◽

Model Systems ◽

Oil Oxidation ◽

Acrylamide Formation ◽

Different Temperatures

ABSTRACT Oil oxidation in an oil-rich system was used to investigate the effect on acrylamide formation. Three kinds of common oil, soybean oil, olive oil, and palm oil, were preheated at different temperatures (120, 150, 180, and 210°C) for different times (0, 5, 10, 15, and 20 h). The oil-rich model systems were composed of pretreated oil and asparagine. Acid value, peroxide value, p-anisidine value, and carbonyl group value were used to monitor the degree of lipid oxidation in the model system. Our results showed that the content of acrylamide increased with oil preheat time and temperature. The highest yield of acrylamide in soybean oil was 0.26 ± 0.012 μg/mL after 20 h of incubation at 210°C. Oil oxidation indices correlated significantly with the content of acrylamide. The peroxide value could provide more information for references about acrylamide formation in soybean and olive oil systems. HIGHLIGHTS

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