This work explores the potential of active packaging containing Mg(II)-polyphenol complex for application in food protection. The polymeric films were produced from tapioca starch or gelatin containing a complex of Mg(II) with ferulic acid (Fer) and phenanthroline (Phen; MgPhenFer). The investigated metal complex is obtained with a high degree of purity without the need for purification and using a low-cost methodology.
Reactive oxygen species such as singlet oxygen (1O2) and the hydroxyl radical (OH•) are responsible for food deterioration because they start the lipid peroxidation process. Studies carried out to evaluate the antioxidant potential of complexes show a total inhibition of 1O2 at a concentration of 1.65 µg.mL-1 and 5.00 µg.mL-1 for peroxyl radical.
The bactericidal activity of the complex against the bacteria related to meat deterioration such as L. innocua, L. monocytogenes, St. aureus, Samonella ssp, E. coli, Ps. putida, Ps. fluorescens S8, Ps. fluorescens S9 was investigated at concentrations ranging from 0.1 mg.mL-1 up to 5 mg.mL-1. The MgPhenFer complex inhibited the growth of all analyzed bacteria at a concentration of 1.0 mg.mL-1.
The antifungal activity of the complex was also evaluated for the pathogens A. niger, P. notatum e Rh. oryzae. In these studies, the MgPhenFer at a concentration of 0,1 mg. mL-1 inhibited 100% of the growth of the molds in relation to the control.
The presence of complexes in gelatin or starch films did not interfere with the transparency of the material obtained, having similar transparency to commercial PET films. Gelatin films showed greater efficiency in the oxygen barrier properties in compared to the starch film. The prevention of the browning process in apple pulps using the starch film containing the complexes was evidenced since the film with MgPhenFer decrease the enzymatic oxidation process.
The films containing the complex have high application potential, MgPhenFer when used freely or in plastic films are promising alternatives to the commercial antioxidant.