Preservation of phytosterol and PUFA during ready-to-eat lettuce shelf-life in active bio-package

Natural preservatives are used in food packages to improve the shelf life of perishable products. Carvacrol and thymol, the main components of oregano essential oil (OEO), are used in active packaging due to their antimicrobial and antioxidant properties. Here, the effect of a bioactive polylactic acid (PLA)/polybutylene succinate (PBS) package in the conservation of lettuce compounds with dietetic value is studied. Analytical pyrolysis (Py- GC/MS) was used to detect changes in dietary components such are phytosterols (PHSTs) and polyunsaturated fatty acids (PUFAs) after 1, 4 and 8 days of packaged in PLA/PBS (95:5%) films containing different OEO concentrations (2–10%). Lettuce PUFAs and PHSTs content decreased when packed in films without OEO. However, when packed in films containing 5 and 10% OEO, these bioactive components were preserved during the estimated lettuce shelf life, for up to 8 days of storage

New Method for Simultaneous Determination of Microcystins and Cylindrospermopsin in Vegetable Matrices by SPE-UPLC-MS/MS

Cyanotoxins are a large group of noxious metabolites with different chemical structure and mechanisms of action, with a worldwide distribution, producing effects in animals, humans, and crop plants. When cyanotoxin-contaminated waters are used for the irrigation of edible vegetables, humans can be in contact with these toxins through the food chain. In this work, a method for the simultaneous detection of Microcystin-LR (MC-LR), Microcystin-RR (MC-RR), Microcystin-YR (MC-YR), and Cylindrospermopsin (CYN) in lettuce has been optimized and validated, using a dual solid phase extraction (SPE) system for toxin extraction and ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) for analysis. Results showed linear ranges (5⁻50 ng g-1 f.w.), low values for limit of detection (LOD) (0.06⁻0.42 ng g-1 f.w.), and limit of quantification (LOQ) (0.16⁻0.91 ng g-1 f.w.), acceptable recoveries (41⁻93%), and %RSDIP values for the four toxins. The method proved to be robust for the three variables tested. Finally, it was successfully applied to detect these cyanotoxins in edible vegetables exposed to cyanobacterial extracts under laboratory conditions, and it could be useful for monitoring these toxins in edible vegetables for better exposure estimation in terms of risk assessment.Funding: This research was funded by the SPANISH MINISTERIO DE ECONOMÍA Y COMPETITIVIDAD (AGL2015-64558-R, MINECO/FEDER, UE); by the FPI grant number BES-2016-078773 awarded to Leticia Díez-Quijada Jiménez; by the FCT project UID/Multi/04423/2013, and the post-doctoral grant (SFRH/BPD/103683/2014) from FCT awarded to Alexandre Campos. Acknowledgments: Spanish Ministerio de Economía y Competitividad for the project AGL2015-64558-R, MINECO/FEDER, UE, and for the grant FPI (BES-2016-078773) awarded to Leticia Díez-Quijada Jiménez. CIIMAR members acknowledge FCT project UID/Multi/04423/2013 and the post-doctoral grant (SFRH/BPD/103683/2014) from FCT awarded to Alexandre Campos