A multifactorial investigation of the capacities of lipid-soluble dietary antioxidants to suppress the thermally induced generation of Lipid Oxidation Products and alternative methods of detection.

Lipid oxidation products (LOPs) such as aldehydes, formed from the degradation of lipid hydrocarbon chains, have been shown to have deleterious health impacts. Despite this, there are minimal regulations that exist for culinary practices to reduce LOP formation in food systems. Techniques such as nuclear magnetic resonance spectroscopy (NMR) can measure these aldehyde species but have limitations that prevent its use in a wider-industry focused market. Recently, low-field NMR (LF-NMR) instruments have been developed offering potential crosscutting tools for adoption as a point of sampling testing instruments. The objectives of this thesis were to evaluate high-field (HF-NMR) and LF-NMR as tools for lipid degradation quantification and LOP formation, and to determine the effectiveness of antioxidant addition for reduction and inhibition of aldehyde formation. HF-NMR was able to determine and assess the impact of fatty acid content across nine culinary oil products, demonstrating elevated aldehyde formation in oil products rich in polyunsaturated fatty acids (PUFAs), relative to monounsaturated fatty acid (MUFA) and saturated fatty acid (SAFA) rich oils. These outcomes were used to support the design of the antioxidant study. LF-NMR instruments were proven capable of the detection of saturated and unsaturated aldehyde species in edible oil products for the first time. Demonstrating the potential future use case of LF-NMR for assessment of LOPs as a measure of oil degradation. A multifactorial investigation of α-tocopherol (AT), butylated hydroxyanisole (BHA) and butylated hydroxytoluene (BHT) at different concentrations for inhibition of aldehyde formation during simulated shallow frying procedures was explored. The data obtained demonstrated that the addition of BHA or BHT to MUFA-rich edible oil products produced a statistically significant (P < 0.05) reduction in aldehyde species formed. Furthermore, the study determined that application of AT to oils containing high to moderate levels of PUFA caused a statistically significant (P < 0.05) pro-oxidant effect, leading to increased formation of aldehydic species over time. Thus, the application of antioxidants in specific edible oils can be utilised to reduce LOP formation during frying processes.

Name dc:type.qualificationname

PhD

Level dc:type.qualificationlevel

Doctoral

Grantor dc:publisher.institution

De Montfort University

Year dc:date.issued

2025

Author dc:creator

• Gibson, Miles

Licence

• https://dora.dmu.ac.uk/bitstreams/90a3d070-12ae-478f-b85a-cf7073137fa4/download