Vladimir Kurćubić

Phenolic Compounds and Biological Activity of Kitaibelia vitifolia

This study was aimed at evaluating the antioxidant activity and efficacy of the ethanolic extract of the endemic plant species Kitaibelia vitifolia in inhibiting the growth of selected fungi and bacteria. Antimicrobial activity was tested using the broth dilution procedure for determination of minimum inhibitory concentration (MIC). MICs were determined for eight selected indicator strains. The highest susceptibility to K. vitifolia ethanolic extract among the bacteria tested was exhibited by Bacillus subtilis ATCC 6633, Staphylococcus aureus ATCC 25923, and Klebsiella pneumoniae ATCC 13883 (MIC=15.62 μg/mL), followed by Escherichia coli ATCC 25922 and Proteus mirabilis ATCC 14153 (MIC=31.25 μg/mL), and Proteus vulgaris ATCC 13315 (MIC=62.50 μg/mL). Of the fungi, Candida albicans ATCC 10231 (MIC=15.62 μg/mL) showed the highest susceptibility, and Aspergillus niger ATCC 16404 (MIC=31.25 μg/mL) had the lowest. Results showed that K. vitifolia extract possesses antioxidant activity, with total antioxidant capacity of 75.45±0.68 μg of ascorbic acid/g and 50% inhibition concentration values of 47.45±0.55 μg/mL for 2,2-diphenyl-1-picrylhydrazyl free radical scavenging activity, 35.35±0.68 μg/mL for inhibitory activity against lipid peroxidation, 95.25±0.52 μg/mL for hydroxyl radical scavenging activity, and 31.50±0.35 μg/mL for metal chelating activity. Total phenolics, flavonoids, condensed tannins, and gallotannins were 85.25±0.69 mg of gallic acid (GA)/g, 45.32±0.55 mg of rutin/g, 54.25±0.75 mg of GA/g, and 41.74±0.55 mg of GA/g, respectively. The phenolic composition of K. vitifolia extract was determined by high-performance liquid chromatography. Rosmarinic acid was found to be the dominant phenolic compound of the extract.

Bovine respiratory disease complex (BRDC): viral and bacterial pathogens in Serbia.

Pathogens causing BRDC in Serbia were investigated. Two herds of beef cattle with bovine respiratory disease were included, with twenty diseased calves (10 from each farm) were chosen for isolation of bacteria on artificial culture media and determination by aerobic cultivation. The most common bacterial pathogen was isolated was Pasteurella multocida. Diffusion method of sensitivity to antibiotics (antibiogram), revealed that Enrofloxacin and Floron were most efficient antibiotics against Pasteurella multocida isolates (100 % isolates sensitive on both antibiotics). From the all examined samples (n=20) using the method of Real Time PCR (RT-PCR and PCR) we determined the genome sequences of bovine respiratory syncytial virus (BRSV), but in none of the samples genome of bovine viral diarrhea virus (BVDV) and bovine herpesvirus-1 (BoHV-1). [Projekat Ministarstva nauke Republike Srbije, br. TR 31001]

The Influence of Sodium Reduction on the Quality and Safety of Hot Dogs

The aim of this study was to evaluate the effects of replacing of sodium nitrite curing salt with the mixture of sodium and potassium chloride (Na-max 27 g/kg-min K 16 g/kg) at a rate of 25%, 50%, 75% and 100% on the quality, microbiological stability and colour of the cooked sausages - hot dog. Five production batches (PB) were manufactured. The first C (control) was prepared according to the manufacturer’s original recipe. Experimental PB I was made by adding 50 g of mixed sodium-potassium salt (25%) and 150 g nitrite curing salt into 10 kg of stuffing, in PB II was replaced 50%, in PB III 75% nitrite salt. Hot-dogs of PB IV were made by adding 200 g (100%) of combined sodium-potassium salt into 10 kg of mass. The results obtained clearly indicate a continuous decrease of sodium content in samples originating from the control group to the experimental samples PB IV, in which the nitrite salt was fully replaced with a mixture of potassium-sodium salt. Replacing of sodium nitrite salt with the mixture of sodium and potassium chloride did not significantly affect examined chemical parameters (content of moisture, proteins, fat, ash) of experimentally prepared hot-dogs. Replacing of sodium nitrite salt with the mixture of sodium and potassium chloride did not significantly affect examined colour (CIE L*, a*, b*) of experimentally prepared hot-dogs.

Prevalence of BVD infection in ruminants in Serbia

The aim of this article is to provide a historical summary of worldwide Bovine Viral Diarrhoea Virus (BVDV) prevalence data through a number of studies, review the current knowledge and published data on the presence and prevalence of BVDV infection among ruminants in Serbia, and consequently open questions as to the possibilities for the implementation of the control programme in Serbia.

EXAMINATION OF THE CERTAIN CHEMICAL CHARACTERISTICS OF DIFFERENT TYPES OF BOILED SAUSAGES PRODUCED IN SERBIA

The objectives of our study were to examine certain chemical quality parameters in samples of various subgroups of boiled sausages and compare obtained values with reference values (Rule book on the quality of minced meat, semi-finished meat and meat products, Official Gazette of RS, no. 31/2012). We used two reference chemical methods: determination of nitrogen and phosphorus content (SRPS ISO 937:1992, SRPS ISO 13730:1999). For determination of hydroxyproline we used M 050 “in house” modified method. We concluded that the total number of tested samples of Fine grounded boiled sausages (n=170), 47 (27.65%) does not match the requirements for the quality provided the above mentioned Rule book, of which 21 samples because lower total protein content (TP) and 33 samples because higher relative protein content of connective tissue (RPC). The most common chemical quality failure of examined Coarsely grounded boiled sausages (n=94) is a higher percent of RPC than allowed (18 - 25 %). We consider in samples of same subgroup lower content of TP in 8 samples (11.11 %). From a total of 8 samples tested Boiled sausages with meat peaces (Sunkarica), all tested samples revealed lower content of TP than allowed (100 %) and 2 samples (25 %) higher relative protein content of connective tissue (RPC). The most common deficiency that reduces the chemical quality of the boiled sausages is higher level of RPC, demonstrated in 53 (19.48 %) of the total (n=272) samples tested. Something minor drawback is the lower percent of TP determined in 37 samples (13.60 %). Total P2O5 content was compatibile with the values permitted by the Rule book in all of 272 examined samples, indicating a strict adherence to regulations when using phosphate as one of the technologically most important additives in the production of boiled sausages.

Investigation of bovine viral diarrhea virus (BVDV) and border disease virus (BDV) infections of sheep in Southwestern Serbia.

Serological assay (virus neutralization test - VNT) was employed to examine blood sera collected from sheep of different age categories reared under different housing systems for the presence of bovine viral diarrhea virus (BVDV) and Border disease virus (BDV) infections in sheep. The objective of the investigation in sheep as reservoir hosts of the viruses was to clarify the potential for their transmission to cattle herds and vice versa. Experimental Group A included 5 mini farms composed entirely of sheep that were not in cohabitation with cattle in the same buildings or on the same pasture. Experimental Group B was made up of five mini sheep farms, whose owners raised cattle as well. A total of 10 blood samples (5 from junior categories of sheep aged up to 12 months and 5 from the older sheep) were secured from each of the 10 mini farms selected for the study. The VNT method did not detect the presence of specific anti-BVDV antibodies to both BVDV genotypes (BVDV-1 and BVDV-2) in any of the 100 test blood serum samples of sheep. Specific anti-BDV antibodies to the BDV Moredun strain were not found in any of the test serum samples of 100 sheep.