# Fatty acids, polyphenols and volatiles as predictive biomarkers of cold-pressed oil stability

## TL;DR

This study identifies specific biomarkers that predict the stability of cold-pressed oils during storage.

## Contribution

The first systematic use of multi-marker and machine learning to identify oil-type-specific deterioration biomarkers.

## Key findings

- Fatty acid degradation, especially linoleic and α-linolenic acid, drives oxidation in cold-pressed oils.
- Volatile aldehydes like hexanal and 2,4-decadienal are key secondary markers of oil deterioration.
- Polyphenols, particularly phenolic acids, degrade rapidly during storage and serve as early stability indicators.

## Abstract

Cold-pressed vegetable oils are rich in PUFAs and bioactive polyphenols but are highly susceptible to oxidative deterioration. Six cold-pressed oils (black cumin, canola, sunflower, high-oleic sunflower, linseed and hempseed oil) from three Austrian suppliers each were stored under household-relevant conditions over six months and analyzed by GC-FID, LC-MS/MS and SPME-GC–MS. Biomarker identification employed Least Absolute Shrinkage and Selection Operator (LASSO), Random Forest regression (RFR) and correlation analysis. Fatty acid degradation, particularly of linoleic and α-linolenic acid, was the main driver of oxidation, while volatile aldehydes such as hexanal, 2,4-decadienal, and (E)-2-nonenal served as key secondary markers. Polyphenols exhibited pronounced, oil-type-dependent depletion during storage, with phenolic acids generally declining earlier than flavonoids and lignans, supporting their use as early-stage stability markers. This is the first study to systematically identify oil-type-specific deterioration biomarkers using an integrated, machine-learning-based multi-marker approach, demonstrating that oxidative stability in cold-pressed oils is best characterized by multi-markers.

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•Six cold-pressed oils were stored for six months under household conditions.•GC-FID, LC-MS/MS, and GC–MS tracked deterioration fingerprints over time.•Polyphenols degraded rapidly, with p-coumaric acid dropping by 87% in 14 days.•LASSO, RFR and correlation analysis identified oil-type-specific biomarkers.•First systematic, multi-marker degradation analysis for oil stability prediction.

Six cold-pressed oils were stored for six months under household conditions.

GC-FID, LC-MS/MS, and GC–MS tracked deterioration fingerprints over time.

Polyphenols degraded rapidly, with p-coumaric acid dropping by 87% in 14 days.

LASSO, RFR and correlation analysis identified oil-type-specific biomarkers.

First systematic, multi-marker degradation analysis for oil stability prediction.