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Effect of Microwave Heating on Phytosterol Oxidation.
Everth Jimena Leal-Castañeda1, Raffaella Inchingolo2, Vladimiro Cardenia
1†Unidad de Investigación y Desarrollo de Alimentos, Instituto Tecnológico de Veracruz, M.A. de Quevedo 2779, Colonia Formando Hogar, Veracruz 91897, México.
Journal of Agricultural and Food Chemistry
|May 15, 2015
Summary
Phytosterols degrade faster alone than with triacylglycerols during microwave heating. The surrounding medium significantly impacts phytosterol oxidation product formation and food safety.
Area of Science:
- Food Chemistry
- Oxidative Stability
- Microwave Processing
Background:
- Phytosterols are crucial food components with health benefits.
- Understanding their stability during processing is vital for food quality and safety.
- Microwave heating is a common food processing technique.
Purpose of the Study:
- To evaluate the oxidative stability of phytosterols under microwave heating.
- To compare degradation in a solid phytosterol film (PSF) versus a liquid mixture with triacylglycerol (TAG).
Main Methods:
- Two model systems (PSF and phytosterols + TAG) were subjected to microwave heating (1000 W) for varying durations (1.5-30 min).
- Degradation kinetics and formation of phytosterol oxidation products (POPs) were analyzed.
- Identified major POPs, including 7-keto derivatives.
Main Results:
- Phytosterols degraded faster in PSF than in PS + TAG, following first-order kinetics.
- No POPs were detected up to 6 minutes of heating in either system.
- POP content was initially higher in PSF but reversed after 30 minutes, with 7-keto derivatives being most abundant.
Conclusions:
- The oxidative stability of phytosterols during microwave heating is influenced by both heating time and the surrounding matrix.
- The presence of triacylglycerols mitigates phytosterol degradation and POP formation.
- Findings are critical for ensuring the quality and safety of microwave-processed foods containing phytosterols.
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