Natalija Dzinic

Antimicrobial activity of composite chitosan biofilms with beeswax and caraway essential oil

In this paper, influence of increasing concentrations of beeswax on the antimicrobial activity of chitosan-caraway essential oil biofilm was investigated. Selected microorganisms for the test were Salmonella Typhimurium and Listeria monocytogenes. Reduction of S. Typhimurium and L. monocythogenes viable counts in bacterial suspension in the presence of chitosan films with or without added beeswax amounted over 80 % after 24 h contact time, and over 95 % after 3 h of contact time, respectively and influence of added beeswax on growth reduction was not detected. However, when number of S.Typhimurium viable cells was analyzed (log CFU/ml), it was shown that addition of beeswax led to increased activity of films, especially for the films with 36 kg/m and 54 kg/mof beeswax. When films were transferred, after 24 h in bacterial suspension, onto Petri dishes with nutrient agar and incubated for 24 h on 37 °C, results also showed beeswax contribution to growth inhibition of S.Typhimurium.

Drying characteristics of traditional fermented sausage Petrovská klobása: The effect of different ripening conditions and use of starter culture

A study was carried out on traditional Serbian dry-fermented sausage Petrovska klobasa in order to investigate the effect of different ripening conditions and use of starter culture (SC) on drying characteristics of this typical meat product. The results related with reduction of diameter, water activity (aw) and moisture content of sausages, obtained during ripening, indicated 30 days faster drying process in controlled industrial ripening room (RR) than in traditional room (TR) (60 vs. 90 days). Along with the ambient (thermo-hygrometric) conditions, this phenomenon was also determined by pH, which was lower in RR sausages (P 0.992) indicate good fit of the experimental data (average moisture content vs. drying time) using third degree polynomial equation, both for RR and TR sausages, whether the samples were produced with or without SC. Additionally, the evolution of moisture content ratio between internal and external fractions of sausages indicated more intense drying in the external ones. This was particularly pronounced in sausages made with SC after 30 days of drying. The use of SC and RR in processing of Petrovska klobasa seems to be a potential technological improvement to shorten the drying period and to prolong the production season of this traditional meat product.