# Using milk fatty acid profile to discriminate milks from cows fed different proportions of hexane- and 2-methyloxolane-defatted soybean meals

Valentin Menoury, Pierre Nozière, Anne Ferlay

► To cite this version:

Valentin Menoury, Pierre Nozière, Anne Ferlay. Using milk fatty acid profile to discriminate milks from cows fed different proportions of hexane- and 2-methyloxolane-defatted soybean meals. Journée des doctorants, post-doctorants et CDD de l'UMR Herbivores, Apr 2025, Saint-Genès-Champanelle, France. Zenodo, 10.5281/zenodo.15308910. hal-05052149

HAL Id: hal-05052149

https://hal.inrae.fr/hal-05052149v1

Submitted on 30 Apr 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_2.png" /></figure>

RÉPUBLIQUE
FRANÇAISE

Liberté
Égalité
Fraternité

INRAE

<figure><img src="image_3.png" /></figure>

UNIVERSITÉ
Clermont
Auvergne

<figure><img src="image_4.png" /></figure>

VetAgro Sup

ecoXTRACT®

<figure><img src="image_5.png" /></figure>

AVIGNON
UNIVERSITÉ

<figure><img src="image_6.png" /></figure>

<figure><img src="image_7.png" /></figure>

PERAQ and DINAMIC teams
UMR Herbivores

Valentin Menoury

Tel.: + 33 (0)6 99 68 26 31

valentin.menoury@inrae.fr

<figure><img src="image_8.png" /></figure>

# Using milk fatty acid profile to discriminate milks from cows fed different proportions of hexane- and 2-methyloxolane-defatted soybean meals

Valentin MENOURYª, Pierre NOZIEREª, Anne FERLAYª

ªUniversité Clermont Auvergne, INRAE, VetAgro Sup, UMR Herbivores, Route de Theix, 63122 Saint-Genès-Champanelle, France

## Introduction

* Soybean meal (SBM) is defatted with hexane (HEX), which is toxic to humans and the environment

* Alternative: 2-methyloxolane (MeOx), a plant-based solvent approved for food extraction in the European Union → production process adjustments (Figure 1) → may affect the chemical composition of SBM (e.g., crude fat content, Maillard reaction products) → may affect lipid digestion (e.g., biohydrogenation) and milk fatty acid (FA) profile.

<figure><img src="image_9.png" /><figcaption>Figure 1. Simplified representation of soybean meal production process.</figcaption></figure>

## Objectives

* Assessing the possibility to discriminate milks from cows fed different proportions of HEX- and MeOx-defatted SBM using milk FA profile.

* Identifying FA that discriminate milks from cows fed different proportions of HEX- and MeOx-defatted SBM.

## Materials and methods

### Experimental design

<figure><img src="image_10.png" /></figure>

### Sampling and measurements

* Morning and afternoon milk samples were freeze-dried and pooled according to milk fat yield.

* Milk FA profile was analyzed after transmethylation using gas chromatography with flame ionization detection (~80 identified FA).

### Multivariate analyses - supervised classification

* Models to discriminate the 4 treatments (100HEX vs 33MeOx vs 67MeOx vs 100MeOx) and models to discriminate the 2 extreme treatments (100HEX vs 100MeOx).

* K nearest neighbors (knn):

* scaled data,

* leave-one-out cross-validation,

* k (1 to 9) optimized using highest accuracy.

* Sparse partial least squares - discriminant analysis (sPLS-DA):

* scaled data,

* centered log-ratio transformation, offset = 5% of the smallest non-zero FA proportion,

* leave-one-out cross-validation,

* number of latent variable(s) (1 to 10) and number of variable(s) per latent variable optimized using the lowest balanced error rate (BER),

* Mahalanobis distance.

## Results

<table><caption>Table 1. Confusion matrix resulting from the knn model built to discriminate 100HEX, 33MeOx, 67MeOx, and 100MeOx (k = 3)</caption><thead><tr><th rowspan="2">Prediction</th><th colspan="4">Reference</th></tr><tr><th>100HEX</th><th>33MeOx</th><th>67MeOx</th><th>100MeOx</th></tr></thead><tbody><tr><th>100HEX</th><td>4</td><td>4</td><td>6</td><td>5</td></tr><tr><th>33MeOx</th><td>4</td><td>4</td><td>2</td><td>2</td></tr><tr><th>67MeOx</th><td>2</td><td>2</td><td>1</td><td>3</td></tr><tr><th>100MeOx</th><td>6</td><td>5</td><td>6</td><td>5</td></tr></tbody><tfoot><tr><td colspan="5">Acc<sup>1</sup> = 0.23</td></tr><tr><td colspan="5">NIR<sup>2</sup> = 0.26</td></tr><tr><td colspan="5">P (Acc > NIR) = 0.76</td></tr></tfoot></table>

<table><caption>Table 2. Confusion matrix resulting from the knn model built to discriminate 100HEX and 100MeOx (k = 6)</caption><thead><tr><th rowspan="2">Prediction</th><th colspan="2">Reference</th></tr><tr><th>100HEX</th><th>100MeOx</th></tr></thead><tbody><tr><th>100HEX</th><td>8</td><td>6</td></tr><tr><th>100MeOx</th><td>8</td><td>9</td></tr></tbody><tfoot><tr><td colspan="3">Acc = 0.55</td></tr><tr><td colspan="3">NIR = 0.52</td></tr><tr><td colspan="3">P (Acc > NIR) = 0.43</td></tr></tfoot></table>

<figure><img src="image_11.png" /><figcaption>Figure 3. Performance of the sPLS-DA model built to discriminate 100HEX and 100MeOx</figcaption></figure>

<figure><img src="image_12.png" /></figure>

¹Accuracy; ²No Information Rate; ³Balanced Error Rate; ⁴Error Rate

## Conclusions

* Knn based on milk FA profile failed to discriminate milks from cows fed different proportions of HEX- and MeOx-defatted SBM.

* sPLS-DA performed better in discriminating 100HEX from 100MeOx, and 5 FA contributing to this discrimination were identified.

* The proportions of these 5 FA were reduced with 100MeOx compared to 100HEX, possibly indicating minor alterations in ruminal biohydrogenation.

* Future work will use univariate analyses to confirm the observed differences in these 5 FA and to test the absence of effects of replacing HEX-defatted SBM with MeOx-defatted SBM on the remaining FA.

<figure><img src="image_13.png" /></figure>

Centre
Auvergne Rhône Alpes - Theix

<figure><img src="image_14.png" /></figure>

Route de Theix
63122 Saint-Genès-Champanelle
France
Tel.: +33 (0)4 73 62 40 00