Vegetables and fruits are vital components of a balanced diet, providing essential nutrients such as dietary fiber, vitamins, minerals, and phytochemicals, which collectively contribute to reducing the risk of chronic diseases, including cardiovascular disorders, cancer, obesity, and mental health conditions [[1], [2], [3], [4], [5]]. In 2023, the worldwide production of fruits and vegetables amounted to 952 million tons, with China accounting for approximately 12 % of this total. This highlights the economic and nutritional importance of these agricultural products [6,7]. Nevertheless, postharvest losses driven by pest infestations, insufficient storage facilities, and inefficiencies in transportation continue to pose a significant challenge. Current estimates suggest that approximately 30 to 40 percent of global agricultural biomass is lost each year [6].

Preservatives are chemicals that inhibit the growth and reproduction of microorganisms, including pesticides and food additives. While preservatives such as fungicides and food additives mitigate spoilage, their residues persist on produce, raising concerns over acute toxicity (e.g., nausea, headaches, and gastrointestinal distress) and chronic risks (e.g., neurodevelopmental impairments, endocrine disruption, and organ toxicity) [8]. For instance, propiconazole induced decreased fecundity in parent zebrafish and disturbed thyroid hormones in offsprings [9,10]. Thus, propiconazole is suspected to be toxic toward human being. Despite regulatory frameworks like the Codex Alimentarius and China’s GB 2763–2021 and GB 2760–2024, critical gaps persist in defining maximum residue limits (MRLs), preharvest intervals, and application guidelines for numerous preservatives, including pyraclostrobin, particularly in crops such as jiaobai, garlic sprouts, and mushrooms [11,12].

The complexity of fruit and vegetable matrices, which include pigments, sugars, lipids, and secondary metabolites, poses significant challenges for accurate preservative residue analysis [13]. Traditional methods often struggle with matrix interference, limiting their reliability. The QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) approach, introduced in 2003, revolutionized residue analysis by simplifying extraction and purification processes [14]. It is a cheap and flexible method, characterized with broad application range, fast, easily operating, and LC and GC amenable [15]. In this study, we enhanced the QuEChERS methodology by systematically evaluating sorbent combinations to minimize matrix effects in complex produce types, including pigmented, fibrous, and sulfur-rich vegetables. Subsequently, ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was used to detect preservative residues. The UPLC-MS/MS consumes less solvent consumption and less time for analysis. Moreover, UPLC column is equipped with slighter particles <2.0 mm and also at tolerable flow up to 5 mL/min, which performed better resolution of peaks, perform faster analysis, sharper, and higher peaks [16]. The optimized method enabled precise quantification of 15 preservatives and 5 metabolites. Additionally, we investigated the degradation kinetics of prochloraz and difenoconazole in garlic sprouts and ginger during storage, assessing compliance with regulatory limits. By integrating advanced analytical techniques with human health risk assessments, this work aims to establish a framework for improving food safety standards and guiding evidence-based pesticide regulations.