Antimicrobial efficiency and sorbic acid migration from active films into pastry dough

Antimicrobial films of 25 and 70¯m thickness, incorporated with 7 and 3% sorbic acid, respectively, were layered with pastry dough without additive and evaluated for sorbic acid migration and antimicrobial efficiency. Pastry dough containing potassium sorbate layered with low‐density polyethylene films (LDPE) was used as a control. The films/pastry sandwiches were stored in LDPE bags at 8±1°C. After 40 days of storage, the dough layered with 25¯m/7% films showed a reduction of 2log cycles in the aerobic mesophilic count; however, there were no significant differences (p ≥0.05) for the psychotropic andStaphylococcus spp.counts. For the dough layered with 70¯m/3% films there were reductions of 2 and 1.5log cycles in the mesophilic and psychotropic counts, respectively. In the control dough, the aerobic mesophilic, psychotropic andStaphylococcus spp.counts increased by 1.5, 1 and 2log cycles, respectively. Regardless of the film, the counts of filamentous fungi, yeasts and coagulase‐positive staphylococcus were<1.0¥102CFU/g, whereas the coliform counts at 35 and 45°C, andEscherichia coliwere<3.0¥100NMP/g. The diffusion coefficients of the sorbic acid from the films into the dough had values in the order of 10‐18m2/s. There were no differences (p ≥0.05) between migration values among the films. The maximum additive release from the 25¯m/7% film into the dough after 20 days was 0.07%, and from the 70¯m/3% film after 9 days was 0.09%. Both values are below the maximum limit allowed by current legislation.