Packaging material should guarantee the longest possible shelf life of food and help to maintain its quality. The
aim of the study was to assess the physicochemical changes taking place during 28-day ageing of beef steaks
packed in two types of multilayer films containing biodegradable polymers – polylactic acid (NAT/PLA) and
Mater-Bi® (NAT/MBI). The control group consisted of steaks packed in synthetic polyamide/polyethylene (PA/
PE) film.
The samples stored in NAT/PLA had significantly lower purge loss than the control samples and the lowest
expressible water amount after 14 and 21 days. Following blooming, the most favourable colour was shown in
steaks stored in NAT/MBI, with the highest values for the L*, a* and C* parameters and the R630/580 ratio, a
high proportion of oxymyoglobin, and the lowest share of metmyoglobin. All steaks, regardless of the type of
packaging material, had acceptable tenderness and were stable in terms of lipid oxidation.