New active antioxidant multilayer food packaging films containing Algerian Sage and Bay leaves extracts and their application for oxidative stability of fried potatoes

Abstract

Abstract The antioxidant activity of Sage leaf (SL) and Bay leaf (BL) extracts was studied. Both plants were extracted using water and ethanol at different concentration, and the antioxidant activity was measured by ABTS [2,2′-azinobis-(3-ethylbenzothiazoline-6-sulfonic acid)] radical cation scavenging and reducing power (RP) methods. In both cases 60% and 80% ethanolic extracts of Sage and Bay leaves showed the highest activity and were incorporated into multilayer films. The initial concentration for 60% ethanolic extracts of Sage and Bay leaves to scavenge 50% of free radical ABTS were 5.67\u202f±\u202f0.26\u202fμg\u202f×\u202fmL−1 and 18.68\u202f±\u202f0.16\u202fμg\u202f×\u202fmL−1 respectively, whereas for 80% ethanolic extracts the concentrations were 7.96\u202f±\u202f0.02 and 14.65\u202f±\u202f0.59\u202fμg\u202f×\u202fmL−1 respectively. The initial concentrations of ethanolic 60% extracts of Sage and Bay leaves to allow absorbance 0.5 for reducing power were 35.38\u202f±\u202f0.19\u202fμg\u202f×\u202fmL−1 and 91.43\u202f±\u202f2.84\u202fμg\u202f×\u202fmL−1 respectively, while for 80% ethanolic extracts of Bay and Sage leaves were 46.01\u202f±\u202f1.21\u202fμg\u202f×\u202fmL−1 and 85.47\u202f±\u202f0.9\u202fμg\u202f×\u202fmL−1 respectively. Then, the multilayer films were exposed to a gas stream enriched with free radicals to evaluate the free radicals scavenging. The new packaging with 60% ethanolic Sage extract exhibited the highest activity with low percentage of hydroxylation (69.64\u202f±\u202f6.86%) followed by that with 80% ethanolic extract for both Bay (85.49\u202f±\u202f5.3%) and Sage (87.09\u202f±\u202f3.93%) leaves extracts. The ability of two active packaging built with 60% ethanolic Sage extract and 80% ethanolic Bay extract to inhibit lipid oxidation of fried potatoes was studied by measuring secondary lipid oxidation products using thiobarituric acid reactive substances (TBARS). Significant lower value of Malondialdehyde (MDA) was obtained for fried potatoes stored in active packaging built with ethanolic 60% extract of Sage and 80% ethanolic extract of Bay leaves (0.342\u202f±\u202f0.01 and 0.392\u202f±\u202f0.02\u202fμg MDA\u202f×\u202fg−1 respectively) at 40\u202f°C for 20 days compared to the control (0.568\u202f±\u202f0.03\u202fμg MDA\u202f×\u202fg−1). Lipid oxidation decreased 40% and 31% for packaging with 60% Sage and 80% Bay ethanolic extracts respectively. The UPLC–MS–QTOF analysis of Sage and Bay leaves extracts revealed the presence of phenolic acids, tannins, flavonoids, and terpenoids. Migration tests from active materials demonstrated the absence of migration.