Impact of thermal treatment and storage on degradation and migration in edible seed oils packaged in PET

This research investigates food safety concerns related to contaminants leaching from plastic packaging into food, focusing on the degradation of sunflower, corn, and rapeseed oils stored in polyethylene terephthalate (PET) containers. The study evaluates the effects of heat exposure (40 °C and 60 °C) and long-term storage (up to 12 months) on the physicochemical properties and sensory qualities of oils purchased from Spain and Germany. The research is divided into two experiments: E1 analyzes oils after heat treatments, and E2 examines them after a year of storage. Heavy metals, such as antimony (Sb), cadmium (Cd), copper (Cu), lead (Pb), and iron (Fe), were detected using advanced mass spectrometry techniques. PET degradation was assessed using Fourier Transform Infrared Spectroscopy (FT-IR/MIR) and Differential Scanning Calorimetry (DSC). Results showed increased acidity, peroxide levels, and sensory degradation, with a rise in “rancid” characteristics after 12 months. PET exhibited chemical changes, including an elevated carbonyl index and amorphization, with copper (Cu) being the most prevalent metal, and Sb levels rising after thermal exposure. This study enhances understanding of how heat and storage affect contaminant migration from PET packaging into seed oils, highlighting implications for food safety and product quality. • Thermal treatments at 20 °C, 40 °C and 60 °C accelerate PET degradation in oil packaging. • Increased Sb migration is linked to PET amorphization under severe conditions. • Oil quality deteriorates over storage, with increases in rancid and plastic defects. • PET crystallinity decreases under stress, impacting container stability. • The carbonyl index reflects advanced stages of PET degradation during storage.