Stability of flavoured phytosterol‐enriched drinking yogurts during storage as affected by different packaging materials

BACKGROUND The aim of this study was to investigate the influence of different packaging materials on storage stability of flavoured phytosterol‐enriched drinking yogurts. White vanilla ( WV ) and blood orange ( BO ) phytosterol‐enriched drinking yogurts conditioned in mono‐layer and triple‐layer co‐extruded plastic bottles were stored at +6 ± 1 °C for 35 days (under alternating 12 h light and 12 h darkness) to simulate shelf‐life conditions. Samples were collected at three different storage times and subjected to determination of total sterol content ( TSC ), peroxide value ( PV ) and thiobarbituric acid reactive substances ( TBARs ). RESULTS TSC was not significantly affected by packaging material or storage time and met the quantity declared on the label. PV was significantly influenced by yogurt type × packaging material × storage time interaction and TBARs by packaging material × storage time interaction. CONCLUSION Between the two packaging materials, the triple‐layer plastic mini bottle with black coloured and completely opaque intermediate layer offered the best protection against lipid oxidation. © 2015 Society of Chemical Industry