Nowadays, cold-pressed rapeseed oil (CPRO) has received increasing attention due to its health-beneficial impact and desired aroma and flavor. Unfortunately, a high level of unsaturated fatty acids and the presence of lipid-accompanying compounds such as metals or free fatty acids (FFA) render a CPRO more susceptible than refined oil to oxidative deterioration. Therefore, extending the shelf-life of CPRO and enhancing its quality parameters is crucial for oil industry producers.
This work focused on the estimation of the effects of added new gelatin strips with polyvinyl alcohol (GEL-PVA) incorporated with amphiphilic antioxidants – sinapic acid esters (SAE) (ethyl sinapate—ESA; octyl sinapate—OSA, and cetyl sinapate—CSA) on antioxidant activity (AA), total phenolic content (TPC), and oxidative stability of CPRO during accelerated shelf-life test. Moreover, synchronous fluorescence (SF) spectroscopy and excitation-emission matrix (EEM) fluorescence spectroscopy were used to observe the most characteristic qualitative changes in CPRO containing GEL-PVA with SAE during the proposed storage period. The results indicated that GEL-PVA films loaded with SEA delayed oxidation and enhanced the antioxidant potential of CPRO stored in marasca glass bottles with proposed active film strips. Furthermore, dipping of film strips in oil samples increased their AA and TPC during the storage period compared to the AA and TPC of fresh CPRO. The addition of GEL-PVA films with SEA inhibited the formation of primary oxidation products measured as peroxide value from 7.04 meq O2/kg to 3.21 – 3.77 meq O2/kg during 14 days of accelerated storage for CPRO samples without and with prepared active film strips, respectively.
To summarize, the proposed sinapic acid ester-gelatin films appear to be promising in extending the shelf life of CPRO.