# Hands‐on protocol for preparing water‐soluble fractions from agri‐food samples for NMR‐based metabolomics analysis

## TL;DR

This paper provides a reproducible protocol for preparing water-soluble metabolite fractions from agri-food samples for NMR-based metabolomics analysis.

## Contribution

The study introduces a standardized workflow for NMR-based metabolomics in the agri-food sector, enhancing reproducibility and data quality.

## Key findings

- The protocol is applicable to both solid and liquid agri-food matrices, demonstrated using strawberry leaves and wine.
- Tailored sample preparation and NMR acquisition steps ensure high-quality and reproducible data.
- The method supports broader applications in food quality, traceability, and safety.

## Abstract

The aim of this study was to address the lack of protocols for nuclear magnetic resonance (NMR)‐based metabolomics in the agri‐food sector by providing a reproducible workflow for the preparation and analysis of water‐soluble metabolite fractions. These fractions, rich in primary metabolites such as sugars, amino acids, and organic acids, are key to assessing agri‐food products' composition, quality, as well as to monitor their manufacturing and development processes. The protocol differentiates solid and liquid matrices, optimizing extraction procedures accordingly. Representative agri‐food products—strawberry leaves (solid) and wine (liquid)—were analyzed to demonstrate the method's versatility and applicability. Key steps include tailored sample preparation, optimization of NMR acquisition, and spectral quality control, ensuring high data quality and reproducibility. The proposed workflow enhances reproducibility across agri‐food metabolomics studies and facilitates integration into broader food quality, traceability, and safety frameworks.

This research protocol outlines a workflow for nuclear magnetic resonance (NMR)‐based metabolomics in the agri‐food sector. Using two case studies—strawberry leaves (solid matrix) and wine (liquid matrix)—it details the procedures for sample preparation, data acquisition, and processing.