Vojislav Banjac

Multi-residue method for determination of selected neonicotinoid insecticides in honey using optimized dispersive liquid–liquid microextraction combined with liquid chromatography-tandem mass spectrometry

The objective of this study was to develop analytical method based on optimized dispersive liquid-liquid microextraction (DLLME) as a pretreatment procedure combined with reversed phase liquid chromatographic separation on C18 column and isocratic elution for simultaneous MS/MS determination of selected neonicotinoid insecticides in honey. The LC-MS/MS parameters were optimized to unequivocally provide good chromatographic separation, low detection (LOD, 0.5-1.0 μg kg(-1)) and quantification (LOQ, 1.5-2.5 μg kg(-1)) limits for acetamiprid, clothianidin, thiamethoxam, imidacloprid, dinotefuran, thiacloprid and nitenpyram in honey samples. Using different types (chloroform, dichloromethane) and volumes of extraction (0.5-3.0 mL) and dispersive (acetonitrile; 0.0-1.0 mL) solvent and by mathematical modeling it was possible to establish the optimal sample preparation procedure. Matrix-matched calibration and blank honey sample spiked in the concentration range of LOQ-100.0 μg kg(-1) were used to compensate the matrix effect and to fulfill the requirements of SANCO/12495/2011 for the accuracy (R 74.3-113.9%) and precision (expressed in terms of repeatability (RSD 2.74-11.8%) and within-laboratory reproducibility (RSDs 6.64-16.2%)) of the proposed method. The rapid (retention times 1.5-9.9 min), sensitive and low solvent consumption procedure described in this work provides reliable, simultaneous, and quantitative method applicable for the routine laboratory analysis of seven neonicotinoid residues in real honey samples.

Fatty Acid Composition and β-Carotene Content in Egg Yolk of Laying Hens Fed with Linseed, Paprika and Marigold

Summary Eggs enriched with n-3 fatty acids and natural pigments are desirable in human food chain due to numerous benefits for health. In this study, we investigated the effects of inclusion of co-extruded linseed and sunflower meal into laying hens’ diet and replacement of synthesized pigment with paprika and marigold flower as sources of natural pigments. Four hundred 18–wk-old Bovan laying hens divided in two groups (control and experiment) were fed for 12 weeks. Fatty acids and β-carotene were monitored every fourth week and successively analyzed. Significantly (p<0.05) increased content of α-linolenic acid in egg yolk in the experimental group in comparison to the control group was observed with addition of linseed, paprika and marigold in laying hens’ nutrition. Nearly the same tendency was observed in eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) content. Supplementation of the co-extruded linseed and sunflower meal into laying hens’ diet demonstrated significantly (p<0.05) lower n-6/n-3 FA ratio in experimental group compared to control group. The obtained results showed that the synthetic pigment added to laying hens’ diet provided better pigmentation of egg yolks after one and two months of the feeding trial than paprika and marigold flower. The concentration of β-carotene in egg yolks increased in experimental group after three months of the treatment, and that was the first time that concentrations of β-carotene did not significantly (p < 0.05) differ among control and experimental group, which shows that paprika and marigold flower as sources of natural pigments can successfully replace synthetic pigment. We shall continue research in this field with other supplemented mixtures, as there are indices for other potential feed enhancements among oily seeds and herbs.

A review of possibilities for control of Salmonella and other pathogenic bacteria in pig feed

Each category of pigs is susceptible to diseases caused by pathogenic bacteria, which negatively reflects on animal health, farm production results or meat quality. Animal feed is one of the potential reservoirs of pathogenic bacteria and infection source of domestic animals. Salmonella spp. is major microbiological hazard in animal feed. Thus, there is importance for implementation of strategies for preventing feed contamination with Salmonella, by minimizing dust, maximizing hygiene of space and processing equipment in feed mills and implementing control measures in each stage of feed production. Existing Salmonella feed contamination can be eliminated by conditioning and later different heat treatments (pelleting, extrusion, expansion) in production process while changing physical structure of the feed (coarsely or finely ground mash or pellets) can influence on conditions for Salmonella development in gastrointestinal tract of pigs. Contamination of feed by pathogenic bacteria and conditions for their development can be also controlled by addition of acidifiers, prebiotics, probiotics and, more recently, essential oils of plant origin, into feed. Various strategies for prevention of feed bacterial contamination, processes for feed decontamination, as well as possibilities for controlling pathogenic bacteria, especially Salmonella, in pig feed were presented and discussed in

Soy Bran Separation Process for Application of Product in the Food Industry

Change of lifestyle, also as contemporary dietary habits of people, requires innovations in the food processing technology and implementation of new ingredients. Fat replacers are well known as ingredients which has been used in the production of low energy products. Furthermore, in the combination with sugar substitutes it is possible to obtain serious energy reduction, while the sensorial properties remains unaffected. A certain lightweight fractions of soy bran separation and milling process could be applied as fat replacers in the food industry, especially in cookie production. Soy bran milled fractions with dietary fibers content (cellulose, hemicellulose, lignin, inulin, pentosans etc.) have been selected for this work. Technological process of soy bran separation and milling starts with a cleaning of the external part of the soy grain, further it is necessary to adjust the moisture content for the efficient mechanical grinding process. New age milling and separation equipment (air separator, cascade classifier, dryer, hammer mill, roller mill) was used for the purposes of experiment. Results obtained with the analyze of microbiological and chemical properties of soy products, along with a probe sieving analysis, indicates a strong potential for use as fat substitutes in bakery, cookie and confectionery production.