Analysis of pesticide residues in pears using the same phytosanitary treatments and grown under the same edaphoclimatic conditions

BACKGROUND: The distribution of pesticide residues within fruit tissues is influenced by the physicochemical properties of the active substances and may vary among cultivars. Information on residue partitioning in different tissues of traditional pear cultivars remains limited. Therefore, this study evaluated the occurrence and distribution of pesticide residues in the peel, pulp, and seeds of six Portuguese regional pear cultivars and one commercial cultivar grown under identical edaphoclimatic conditions and subjected to the same phytosanitary treatments. RESULTS: Pesticide residues in peel, pulp, and seeds were evaluated by a validated QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) liquid chromatographic–mass spectrometric method. The distribution of residues was closely correlated with the physicochemical characteristics of the active compounds. Highly lipophilic chemicals with poor systemic mobility, such as pyriproxyfen and triflumuron, were largely deposited in peel, whereas moderately systemic compounds including fluopyram, chlorantraniliprole and trifloxystrobin were also discovered in seeds. In most cultivars, the peel was the primary residue reservoir, contributing around 85% of total residues, followed by seeds at 13% and pulp at 1%. The most often found pesticide was difenoconazole, followed by indoxacarb and pyriproxyfen. Differences between cultivars indicated that specific fruit characteristics may be involved in residue partitioning and retention patterns. CONCLUSION: The distribution of pesticide residues in pears is influenced by the physicochemical properties of the pesticide and the cultivar-specific variables Residues were mainly found in the peel and to a lesser level in the seeds, and the pulp was found to be little contaminated or uncontaminated. These results contribute to a better knowledge of residue behavior in pear cultivars and may assist future risk assessment, monitoring tactics, and residue management practices. © 2026 Society of Chemical Industry.