Impact of nonthermal plasma on lipid oxidation in various lipid matrices and identifying the key reactive species involved

Monday, April 29, 2024

10:52 AM – 11:09 AM EDT

Room: 524c

Presenting Author(s)

Danyang Liu, MA

PhD Student
Ghent University
Gent, Belgium

Co-Author(s)

CV

Charlie Van Paepeghem

PhD Student
Ghent University, Belgium
JS

Joke Sierens

PhD Student
Ghent University, Belgium
MN

Mehrnoush Narimisa

Dr.
Ghent University, Belgium
AN

Anton Nikiforov

Dr.
Ghent University, Belgium
ND

Nathalie De Geyter

Prof.
Ghent University, Belgium
KD

Kristof Demeestere

Prof.
Ghent University, Belgium
BD

Bruno De Meulenaer

Prof.
Ghent University, Belgium

Abstract: Nonthermal plasma is a mild processing technology for food preservation. Its impact on lipid oxidation was investigated in this study. Stripped methylesters (FAME) were considered as a basic lipid model system and were treated by a multihollow surface dielectric barrier discharge. Plasma-induced effects were first examined by classical lipid oxidation indicators such as peroxide value and p-anisidine value. The formation of specific volatile oxidation products including hexanal, nonanal, trans-2-hexenal and methyl 9-oxononanoate was determined using SPME-Headspace-GCMS analysis. The production of selected non-volatile oxidation products including epoxy-, oxo- and hydroxy-FAME was monitored by GC-FID and GC-MS analyses. Despite being treated with the same intensity of plasma, the amount of oxidation products increased in parallel with the unsaturation degree of the studied FAME.
In dry air plasma, O3, ·NO2, ·NO3, and 1O2 were identified as the main reactive species reachingthe sample surface. In humid air plasma, less O3 was detected, but ONOOH and O₂NOOH were generated and presumed to play a role in lipid oxidation. Ozone mainly resulted in the formation of carbonyl substances via the trioxolane pathway, while reactive nitrogen species (i.e., ·NO2, ·NO3, ONOOH, and O2NOOH) led to the formation of hydroperoxides. The impact of short-living radicals (e.g., ·O, ·N, ·OH, and ·OOH) was restricted in general, since they dissipated too fast to reach the sample.·NO, HNO3, H2O2, and UV radiation did not induce lipid oxidation. All the reactive species identified in this study were associated with the presence of O2 in the input gas.