RESEARCH PAPER Nano selenium as antioxidant agent in a multilayer food packaging material Paula Vera 1 & Yolanda Echegoyen 1 & Elena Canellas 1,2 & Cristina Nerín 1 & María Palomo 3 & Yolanda Madrid 3 & Carmen Cámara 3 Received: 22 March 2016 /Revised: 1 July 2016 /Accepted: 7 July 2016 # Springer-Verlag Berlin Heidelberg 2016 Abstract Selenium nanoparticles (SeNPs) were incorporated in a flexible multilayer plastic material using a water-base adhesive as vehicle for SeNPs. The antioxidant performance of the original solutions containing spherical SeNPs of 50–60 nm diameter, the adhesive containing these SeNPs, and the final multilayer plastic material to be used as food packaging were quantitatively measured. The radical scaveng- ing capacity due to SeNPs was quantified by a free radical assay developed in the laboratory and by the diphenyl-1- picrylhydrazyl (DPPH) method. DPPH was not efficient to measure the scavenging capacity in the multilayer when the free radical scavenger is not in the surface in contact with it. Several multilayer laminated structures composed by [PET (20 m)–adhesive–LDPE (with variable thickness from 35 to 90 μm)] were prepared and measured, demonstrating for the first time that free radicals derived from oxygen (OH·, O 2 ·, and O 2 H) cross the PE layer and arrive at the adhesive. SeNPs remain as such after manufacture and the final laminate is stable after 3 months of storage. The antioxidant multilayer is a non-migrating efficient free radical scavenger, able to protect the packaged product versus oxidation and extending the shelf life without being in direct contact with the product. Migration tests of both Se and SeNPs to simulants and hazelnuts demonstrated the non-migrating performance of this new active packaging. Keywords Antioxidant . Free radical scavenger . Selenium nanoparticles . DPPH . Migration . Active packaging Introduction The profound changes in production, distribution, and storage of foods as well as the increased society demand that requires good quality products and longer shelf life lead to the need of new ideas for the packaging sector. Some of these needs have been satisfied with the use of active packaging, either antiox- idant or antimicrobial packaging materials. They are classified into two big groups: scavenging systems or releasing systems. The first one is able to remove oxygen, water, ethylene, free radicals, etc. from the package, thus reducing the oxidation processes or early maturation of the packaged food. The other option releases mainly antimicrobial agents, which are capa- ble to inhibit the microbial growth extending its shelf life. In both cases, the system consists of incorporating in the pack- aging material specific substances, usually called active agents, which will act either as antioxidants or antimicrobials for food [1–8]. Although the idea of having the preservatives in the packaging materials instead of in the food is very attrac- tive, to get these materials is very difficult. There are a series of steps to consider and among them the demonstration of the efficiency is the key point. This faces a new analytical chal- lenge, in which quantitative measurements at high level of sensitivity are required for direct application to a packaging material without previous extraction or dissolution. In this work, the efficiency of a new antioxidant material containing Se nanoparticles has been demonstrated. * Cristina Nerín cnerin@unizar.es 1 Analytical Chemistry Department, GUIA Group, I3A, CPS, University of Zaragoza, Maria de Luna 3, 50018 Zaragoza, Spain 2 Samtack Adhesivos Industriales, C/ Cerámica, n°3, Pol. Ind. Magarola Sud, 08292 Esparreguera, Barcelona, Spain 3 Analytical Chemistry Department, Facultad de Ciencias Químicas, University Complutense of Madrid, Avenida Complutense s/n, 28040 Madrid, Spain Anal Bioanal Chem DOI 10.1007/s00216-016-9780-9