# Chemometric Evaluation of Official and Advanced Methods for Detecting Olive Oil Authenticity in Canned Tuna

## TL;DR

This study tested methods to verify olive oil authenticity in canned tuna, finding that combining traditional and advanced techniques improves detection accuracy.

## Contribution

The study demonstrates the enhanced effectiveness of combining official and advanced methods, such as CSIA, for olive oil authentication in canned tuna.

## Key findings

- All 10 samples were confirmed authentic using EU standards and scientific literature.
- CSIA of FAs improved detection of adulteration compared to FA analysis alone.
- Storage affected FA composition and δ13C values due to oxidative degradation.

## Abstract

This study evaluated the authenticity of olive oil in canned tuna products from the Slovenian market using both official methods, including fatty acid (FA) profiling, determination of the equivalent carbon number difference (ΔECN42), and sterol analysis, and an advanced method: stable carbon isotope analysis (δ13C) of FAs obtained through compound-specific isotope analysis (CSIA). Results from both methods confirmed that all 10 samples were authentic, as per the limits set by EU Regulation 2022/2104 and supported by the scientific literature. Method performance was further evaluated by adulterating the olive oil from the canned tuna with 5–20% vegetable oil (VO) or hazelnut oil (HO). While FA analysis struggled to differentiate adulterants with similar FA profiles, CSIA of FAs significantly improved detection. However, distinguishing between VO and HO blended samples remained challenging. PLS-DA analysis further supported the potential of using δ13C values of FA for food authentication. Storage of adulterated samples also influenced FA composition, leading to significant changes in MUFA/PUFA ratios and δ13C values, which became less negative, likely due to oxidative degradation. In summary, the combination of official and advanced methods, supported by chemometric analysis, offers a robust approach to ensuring the authenticity of olive oil in canned tuna.