Effect of packaging technology on microbiological and sensory quality of a cooked blood sausage, Morcela de Arroz, from Monchique region of Portugal

Morcela de Arroz (MA), a popular Portuguese blood sausage, with high pH and water activity (aw), is traditionally commercialized without preservatives and unpacked. This study evaluated the best packaging solution to extend MA shelf life stored at 4 ± 1 °C for 44 days: without packaging (WP), vacuum (VP) and modified atmosphere packaging (MAP) (80% CO2; 20% N2). Mesophilic (MTVC), psychrotrophic (PTVC), lactic acid bacteria (LAB), pseudomonads, molds and yeasts, Enterobacteriaceae, Listeria monocytogenes, Salmonella spp., Bacillus cereus, Clostridium perfringens, sensory properties, pH, moisture and aw were studied. Moisture and aw decreased (p < 0.05) in WP. pH decreased in WP and MAP during storage. MTVC and PTVC counts increased to values around 7 log CFU/g at 44 days of storage. LAB and Enterobacteriaceae counts were higher (p < 0.05) in VP. Pseudomonads were inhibited (p < 0.05) by MAP after 8 days of storage. Sensory parameters were affected (p < 0.05) by packaging and storage time. Globally, MAP performed better.