Eureka! Institutional Repository

The need to find innovative and safe packaging with a small environmental impact is growing rapidly. The development of innovative packaging with a perspective of use in foods is necessary. In the present study, the antimicrobial activity of different solutions was studied with the perspective of use into food packaging materials in order to create new active packaging. Firstly, the antimicrobial activity of Titanium ammonium citrate (0.1 and 0.5 mM) was examined against two Gram-positive bacteria, Listeria monocytogenes and Staphylococcus aureus and two Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa. There was no significant (p>0.05) antimicrobial activity using either of the two concentrations examined against the tested bacteria. Moreover, the antimicrobial properties of polylactic acid (PLA) films containing 2% (w/w) and 5% (w/w) sodium nitrite were examined against seven microorganisms L. monocytogenes, S. aureus, Bacillus cereus, Salmonela Enteritidis, Salmonela Typhimurium, E. coli and P. aeruginosa. No inhibition zones were observed, although all the bacteria tested did not grow under the films. Furthermore, the antimicrobial properties of sodium nitrite, potassium sorbate, sodium benzoate and propionic acid incorporated in starch films at a final concentration of 0,54% (w/w), were examined against all the bacteria mentioned previously. There were no zones of inhibition observed, however L. monocytogenes, B. cereus, S. Enteritidis, E. coli and P. aeruginosa did not manage to grow under some of the films or their equivalent controls. In contrast, S. Typhimurium did not grow under the sodium benzoate film but was able to grow under the control. Starch-based packaging containing 0,00075% (w/w) sodium nitrite (NaNO2) were developed to improve the storage stability of raw minced meat. The samples were stored at 4 oC for 5 days. The samples were examined for pH, moisture loss, weight loss and the microbial counts of Aerobic Plate Count, Psychotrophic Plate Count and Lactic Acid Bacteria. Population of aerobic mesophiles, physcotrophs and lactic acid bacteria in raw minced meat samples, which were packaged in starch films with 0,00075% (w/w) NaNO2 were found to be significantly (p<0,05) lower by 1 log cfu/g compared to the raw minced meat samples which were packaged in starch films without NaNO2 and the control ones in nylon commercial packaging on day 2 and 3.