The Effects of Nisin and Nisin-nanoparticles as Nitrite Replacement on Physicochemical, Microbiological, Sensory Properties and Shelf Life of Frankfurter Type Sausage

The effect of 500 ppm mixed plant extracts (green tea, stinging nettle and olive leaves extract in the same rates) in combination with nisin (200 ppm) and nisin nanoparticles (200 ppm) was studied to produce nitrite free frankfurter sausage. Nitrite free frankfurter sausages in three treatments containing 500 ppm plant extract + 200 ppm of nisin, 500 ppm plant extract + 200 ppm nisin nanoparticles with control sample (120 ppm sodium nitrite) were produced, then packaged in polyethylene bags in vacuum condition and physicochemical, quality, microbiological and sensory properties were evaluated during 45 days of storage. The results showed that the use of nisin and nisin nanoparticles had no significant effect (P>0.05) on moisture, fat, protein and ash content. Nisin nanoparticles, due to the presence of chitosan in the capsule structure, prevented the lipid oxidation and the sausages containing these compounds had the lowest TBARS at the end of the storage. Total viable count, molds and yeasts counts increased significantly (P<0.05) during storage. At the end of 45 days, sausages containing sodium nitrite and nisin nanoparticles had the lowest total viable bacterial and molds and yeasts counts, respectively. The count of Staphylococcus aureus (2.5 Log CFU/g) and Escherichia coli (2 Log CFU/g) decreased significantly during storage (P<0.05). It was found that sausage containing nisin nanoparticles had high sensory scores compared to other treatments. The results showed that the use of 200 ppm nisin nanoparticles in combination with 500 ppm of mixed extracts could be a novel step in the production of nitrite free frankfurter sausage with good quality characteristics and extended shelf life.