The study examined the photodegradative efficiency of ZnO and TiO2 in degradation of antibiotics in aqueous matrices. Among several types of antibiotics, four antibiotics were chosen to feature the major classes of th...The study examined the photodegradative efficiency of ZnO and TiO2 in degradation of antibiotics in aqueous matrices. Among several types of antibiotics, four antibiotics were chosen to feature the major classes of these compounds： amoxicillin, erythromycin, streptomycin and ciprofloxacin. Degradation of antibiotic solutions was carried out mainly under UV-light irradiation in a set time with the presence of small quantity of zinc oxide or titanium dioxide. Solutions were analyzed with HPLC chromatography and degradation percentages were calculated from ratio between pick area associated to no degraded drug solution and degraded drug solution＇s pick area. Meanwhile, toxicity of antibiotics and degrading compounds were investigated using a biosensor system, consisting of Clark＇s electrode associated with a portion of agar medium culture containing Saccharomyces Cerevisiae yeast cells. This way, it was possible to define the oxygen that was consumed by yeast cells. Toxicity associated to antibiotics and degrading products are related to decrease of oxygen concentration in solution. It is clear that zinc oxide is slower than titanium dioxide to degrade antibiotics, but zinc oxide shows better photodegradation efficiency than titanium dioxide in spite of its small specific superficial area.展开更多
Petrovska klobasa is a traditional dry fermented sausage produced in the Autonomous Province of Vojvodina. Formation of nine hiogenic amines was determined in three sausage groups produced from hot deboned （A1） and ...Petrovska klobasa is a traditional dry fermented sausage produced in the Autonomous Province of Vojvodina. Formation of nine hiogenic amines was determined in three sausage groups produced from hot deboned （A1） and cold meat （B1, B3） during drying and ripening in traditional room （A1, B1） and in industrial ripening chamber （B3）. Dansyl chloride derived amines were analysed by high-performance liquid chromatography with diode-array detector （HPLC-DAD） on Eclipse XDB-C18 column. Histamine, the most important amine from food safety point of view, was not found in any of the analyzed samples. Serotonin and spermidine were also not detected in any samples, while spermin was determined in all analyzed samples. At the end of drying, phenylethylamine was the predominant amine in A1 sausage group （51.6 mg/kg）, and tryptamine in B1 （38.1 mg/kg） and B3 （28.7 mg/kg） sausage groups. At the end of ripening, tryptamine was the predominant biogenic amine in all sausage groups （133, 121 and 39.8 mg/kg in A1, B1 and B3 groups, respectively）. Total level of biogenic amines in all investigated sausages did not exceed 174 mg/kg at the end of drying and 238 mg/kg at the end of ripening period. Tryptamine and cadaverine may be used as indicators of total biogenic amines for sausages produced in traditional and indusrial conditions from hot deboned and cold meat.展开更多
文摘The study examined the photodegradative efficiency of ZnO and TiO2 in degradation of antibiotics in aqueous matrices. Among several types of antibiotics, four antibiotics were chosen to feature the major classes of these compounds： amoxicillin, erythromycin, streptomycin and ciprofloxacin. Degradation of antibiotic solutions was carried out mainly under UV-light irradiation in a set time with the presence of small quantity of zinc oxide or titanium dioxide. Solutions were analyzed with HPLC chromatography and degradation percentages were calculated from ratio between pick area associated to no degraded drug solution and degraded drug solution＇s pick area. Meanwhile, toxicity of antibiotics and degrading compounds were investigated using a biosensor system, consisting of Clark＇s electrode associated with a portion of agar medium culture containing Saccharomyces Cerevisiae yeast cells. This way, it was possible to define the oxygen that was consumed by yeast cells. Toxicity associated to antibiotics and degrading products are related to decrease of oxygen concentration in solution. It is clear that zinc oxide is slower than titanium dioxide to degrade antibiotics, but zinc oxide shows better photodegradation efficiency than titanium dioxide in spite of its small specific superficial area.
文摘Petrovska klobasa is a traditional dry fermented sausage produced in the Autonomous Province of Vojvodina. Formation of nine hiogenic amines was determined in three sausage groups produced from hot deboned （A1） and cold meat （B1, B3） during drying and ripening in traditional room （A1, B1） and in industrial ripening chamber （B3）. Dansyl chloride derived amines were analysed by high-performance liquid chromatography with diode-array detector （HPLC-DAD） on Eclipse XDB-C18 column. Histamine, the most important amine from food safety point of view, was not found in any of the analyzed samples. Serotonin and spermidine were also not detected in any samples, while spermin was determined in all analyzed samples. At the end of drying, phenylethylamine was the predominant amine in A1 sausage group （51.6 mg/kg）, and tryptamine in B1 （38.1 mg/kg） and B3 （28.7 mg/kg） sausage groups. At the end of ripening, tryptamine was the predominant biogenic amine in all sausage groups （133, 121 and 39.8 mg/kg in A1, B1 and B3 groups, respectively）. Total level of biogenic amines in all investigated sausages did not exceed 174 mg/kg at the end of drying and 238 mg/kg at the end of ripening period. Tryptamine and cadaverine may be used as indicators of total biogenic amines for sausages produced in traditional and indusrial conditions from hot deboned and cold meat.
