Headspace Volatile Profile of Fresh-Cut Broccoli Raab in PET Packaging as Affected by Microperforation

This work investigated the effect of high CO₂/low O₂ conditions in polyethylene terephthalate (PET) packaging on the quality of fresh-cut broccoli raab, focusing on volatile organic compounds (VOCs). Fresh broccoli raab was stored for 16 days at 5 °C in microperforated (MP) and in non-microperforated (NMP) PET packaging. During storage, the NMP atmosphere reached approximately 17% CO₂ and 0% O₂, while MP packaging maintained approximately 2% CO₂ and 19% O₂. NMP samples became unacceptable by day 7 due to loss of firmness and tissue deterioration, while MP samples remained acceptable until day 10, after which yellowing and shrivelling occurred. By day 10, MP VOCs were characterised by ß-caryophyllene, Z-3-hexen-1-ol acetate, and hexen-1-ol, likely generated by enzymatic reactions associated with tissue senescence. NMP packaging showed a high presence of sulphides, isothiocyanates, and nitriles, indicative of severe tissue damage in anaerobic conditions. These alterations in VOCs led to strong, unpleasant sensory notes in NMP samples. This study demonstrated that MP PET packaging can effectively extend the marketable shelf-life of fresh-cut broccoli raab to 10 days, preserving sensory quality and reducing off-odour formation. The findings highlight the potential of microperforated PET as a sustainable solution for enhancing the shelf-life and quality of perishable produce.