The effect of nisin on L. monocytogenes in Turkish fermented sausages (sucuks)

Turkish fermented sausage (sucuk) is a traditional, well-known meat product in Turkey. The aim of this study was to evaluate the effect of different nisin concentrations on Listeria monocytogenes in experimentally contaminated sucuk. Analyses were performed on at 0, 1, 3, 5, 7, 10, 15, 20, 25 and 30days for L. monocytogenes and other microbiological parameters (Total mesophilic aerobic bacteria and lactic acid bacteria) and physico-chemical parameters (pH, a(w) and moisture content).The sucuk dough was contaminated with L. monocytogenes ATCC 7644 at a concentration of 10(6)cfu/g, and the dough was divided into six equal groups. Each group was treated separately with different nisin concentrations (0, 5, 10, 25, 50 and 100μg/g). No L. monocytogenes surviving cells were detected in groups which contained 100μg/g and 50μg/g nisin at day 20 and 25, respectively (p<0.001). In conclusion, the inhibition of L. monocytogenes in sucuk increases with the increasing concentrations of nisin.     

Comparison of a competitive ELISA with an HPLC method for the determination of aflatoxin M1 in Turkish White, Kasar and Tulum cheeses

AFM1 is a hydroxylated metabolite produced when ruminants ingest contaminated feed with AFB1 and transferred to dairy products such as cheese, which represents an important risk factor for consumers. Turkish White, Kashar and Tulum cheeses are traditional cheese types in Turkey. This study was planned to compare the performance of a competitive ELISA for the determination of AFM1 in Turkish White, Kasar and Tulum cheeses against a new HPLC method. For this purpose, different AFM1 concentrations (50–400 ng/kg) were added to the cheese samples and the toxin levels were determined by ELISA and HPLC. Also, both methods were performed in 24 real samples obtained from different markets. In conclusion, the results obtained by ELISA in this study were related to those by HPLC for AFM1.