RESEARCH ARTICLE Pumpkin seed oil cake/polyethylene film as new food packaging material, with perspective for packing under modified atmosphere Senka Popovi  c 1 | Nevena Hromiš 1 | Danijela Šuput 1 | Sandra Bulut 1 | Svetlana Vitas 2 | Marina Savi  c 1 | Vera Lazi  c 1 1 Faculty of Technology Novi Sad, University of Novi Sad, Bul.cara Lazara 1, Novi Sad, 21000, Serbia 2 Spektar d.o.o, Rudnic ˇ ka BB, Gornji Milanovac, 32300, Serbia Correspondence Nevena Hromiš, Faculty of Technology Novi Sad, University of Novi Sad, Bul.cara Lazara 1, 21000. Novi Sad, Serbia. Email: nevena.krkic@uns.ac.rs Funding information Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja, Grant/Award Number: 451-03-68/2020-14/ 200134 Abstract Biopolymer packaging materials show increasing perspective in food packaging. Main limitation remains their high water sensitivity and poor water vapour barrier proper- ties, compared to non polar materials of synthetic origin like polyethylene. In this paper, biopolymer layer obtained from by-product of oil industry (pumpkin seed oil cake) was laminated on polyethylene in order to obtain new packaging material that would preferably combine water barrier properties of polyethylene and oxygen bar- rier properties of biopolymer composite material and perform satisfactory mechanical properties. Obtained two-layer material showed good barrier properties for water vapour (7–8 g/m 2 24h), as well as oxygen (12–45 cm 3 /m 2 24h) and light. In addition, mechanical and water sensitivity tests were performed and results showed that new material inherited biopolymer film water sensitivity and mechanical properties with slight improvement. Measured tensile strength and elongation at break was 2–4 MPa and 150–250% in transversal direction and 6–8 MPa and 100–150% in longitudinal direction. Packing in modified atmosphere assay showed that new material can be used for this purpose with good control of oxygen concentration, while packing under increased concentration of CO 2 could be performed for shorter storage period. New two layer material shows promising properties for sensitive food packing under modified atmosphere conditions with reduced use of synthetic, oil-based materials. KEYWORDS biopolymer, modified atmosphere, properties, pumpkin oil cake, two-layer packaging material 1 | INTRODUCTION From its most primitive shapes and uses, until today, packaging has been a mean that accepts product and protects it until final use. Food products are highly susceptible to external influences. Food consists of large number of chemically active compounds (proteins, carbohydrates, lipids, vitamins, organic acids, alcohols, pigments, esters, aldehydes, phenols, etc.) that are easily susceptible to change and, under certain conditions, react with each other or with external reagents, thus causing undesirable changes in the packaged product. The sustainability of the product is dependant on the type and charac- teristics of the product itself, the preservation procedures applied, and is directly dependent on the quality and potential of the packag- ing and packing. 1,2 Biopolymer based packaging materials have been extensively researched for application in food packaging. Principal presented ben- efits of this type of packaging are natural and renewable origin, possi- bility of obtaining edible packaging, as well as, in most cases, their biodegradability and/or compostability. Biopolymer based materials in general show low to medium tensile strength with fair elongation at Received: 25 March 2020 Revised: 10 July 2020 Accepted: 31 August 2020 DOI: 10.1002/pts.2537 Packag Technol Sci. 2020;1–9. wileyonlinelibrary.com/journal/pts © 2020 John Wiley & Sons, Ltd. 1