Migration of red grape extract components and glycerol from soybean protein concentrate active films into food simulants

Migration of glycerol and red grape extract (RGE) components from bioactive soybean protein concentrate (SPC) films into aqueous and fatty food simulants was performed as a function of temperature. GC-MS and HPLC methods were applied to quantify the amount of glycerol and RGE individual components migrated into the simulants. Overall migration (OM) in fatty simulant was below the limit imposed by the legislation of 10 mg/dm(2). RGE components migrated preferentially to the fatty simulant due to the structural complexity and solubility of the migrant. Contrarily, glycerol was released at higher extent and rate into aqueous medium, due to its inherent hydrophilic nature. Migration process was described by Fick's diffusion second law, and the apparent diffusion coefficient (D-app) was derived from an analytical solution. Dapp values ranged from 1.5 10(-14) to 1.6 10(-13) cm(2) s(-1) under different conditions. The efficiency of SPC films was tested on steam cooked mackerel chunks during storage 4 +/- 1 degrees C for 21 days. Antioxidant activity of films decayed upon storage but both kept more that 50% of their initial radical scavenging activity after 21 d. SPC-RGE film delayed the maximum oxidation by 3 d compared to the control and samples packed in SPC film, more likely due to the lower oxygen permeability and higher radical scavenging activity of SPC-RGE film. Findings suggested that films based on SPC containing RGE can be considered as potential sustainable active food packaging material.