Lemon Peel and Juice: Metabolomic Differentiation

Lemon is one of the most significant crops globally, with annual production exceeding 20.8 million tons in 2021. Spain leads the production in Europe with over 62% of lemon production (1.17 million tons in 2021). This study evaluated the real impact of cultivation conditions (rootstock and culture medium) on the compositional characteristics of ‘Verna’ lemons (peel and juice) using 1H-MNR metabolomic identification techniques and multivariate analyses. Twenty metabolites were identified in both the peel and juice samples. Arginine, phenylalanine, ethanol, and trigonelline were absent in the peel samples but present in all the juice. On the other hand, the metabolites asparagine, glutamate, formate, and malate were present in the peel samples but absent in the juice. The analysis of the results indicates that the rootstock had a significant impact on the metabolites related to the energy metabolism of the plant, which directly affects the development of fruits and the influence of the culture conditions (rootstock and culture medium) on the plant’s adaptive response and modification of metabolic pathways.