Monitoring the metabolite content of seasoned zucchinis during storage by NMR-based metabolomics

This study applied ¹H NMR metabolomics to monitor the metabolite content of baked and seasoned zucchinis packaged in both compostable and plastic trays. Polar extracts of samples stored at 4 °C up to 35 days were investigated to check for metabolite changes upon shelf life. The evolution of the integral values of only the main metabolites responsible for sample differentiation (lactate, acetate, malate, α and β glucose and sucrose) were further analysed and compared. In particular, the evaluation of lactate and acetate amount, considered markers of fermentation progress, showed a comparable performance for the two types of packaging in preserving the freshness of seasoned zucchinis, confirming the maintenance of food product composition within the declared shelf life period in the recommended storage conditions. Albeit preliminary, the results support the NMR metabolomics as a tool for identifying candidate metabolites to monitor the shelf life of foods, thereby improving the understanding of molecular changes during storage.