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Sitosterol as an antioxidant in frying oils
1Department of Agricultural, Food & Nutritional Science, University of Alberta, 410 Agriculture/Forestry Centre, Edmonton, AB T6G 2P5, Canada. ashutosh.singh@ualberta.ca
Food Chemistry
|December 4, 2012
Summary
Sitosterol acts as an antioxidant by reducing harmful polymer formation in oils during prolonged high-temperature frying. This helps maintain oil integrity and stability, crucial for food preparation.
Area of Science:
- Food Chemistry
- Lipid Oxidation
- Antioxidant Activity
Background:
- High-temperature processing of oils can lead to degradation.
- Understanding the role of additives like sitosterol is important for food stability.
Purpose of the Study:
- To investigate the antioxidative effects of sitosterol in various oils during prolonged heating.
- To determine the impact of sitosterol on triacylglycerol (TG) degradation products.
Main Methods:
- Sitosterol was added at 1%, 2%, and 5% to triolein and vegetable oils (canola, sunflower, flaxseed).
- Oils were continuously heated at 180 °C for up to 72 hours.
- High Pressure Size Exclusion Chromatography (HPSEC) was used to analyze changes in TG polymers, monomers, and hydrolysis products.
Main Results:
- Sitosterol significantly reduced triacylglycerol (TG) polymer formation in all tested oils.
- Increased levels of intact TG monomers and TG ester hydrolysis were observed with higher sitosterol concentrations.
- The antioxidative effect is potentially linked to the conversion of sterol to steradiene.
Conclusions:
- Sitosterol demonstrates significant antioxidative properties during high-temperature oil processing.
- Sitosterol helps mitigate oil degradation by inhibiting polymer formation.
- Further research into sterol conversion mechanisms could elucidate its full protective role.
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