Enhancement of sausages shelf life using natural antimicrobials and propolis extract

The present work assessed the impacts of nisin (200 mg/kg) and nisin-nanoparticles (NNPs; 200 mg/kg) in combination with propolis ethanolic extract (PEE; 1% and 3%) on quality and stability of sausage during refrigerated period. The treated meat batters were mechanically stuffed into polyamide casings, packaged in vacuum conditions and analyzed at days 1, 15, 30 and 45. Sausages treated with combined NNPs and PEE displayed higher total phenolic content (2.14–5.41 mg GAE/g DM), pH values (5.27–5.80) and sensory scores (3.70–3.93) with low hardness (34.9–37.7 kg m/s2) and TBARS values (1.41–2.85 mg MDA/kg) throughout keeping period. At day 45, treated samples with 200 mg/kg NNPs + 3% PEE indicated 0.28 Log CFU/g reduction in TVC, 0.16 CFU/g in Clostridium perfringens, 0.23 in E. coli, 0.65 in Staphylococcus aureus, and 0.37 CFU/g in mold and yeast count compared with control (120 ppm nitrite). Hence, this work aims to assess the performance of nisin compounds + PEE in the quality improvement of frankfurter-type sausage kept for 45 days (4 °C) to produce novel and practical nitrite substitutes.