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Experimental and Discrete Element Model Investigation of Limestone Aggregate Blending Process in Vertical Static and/or Conveyor Mixer for Application in the Concrete Mixture
No full textThe numerical model of the granular flow within an aggregate mixture, conducted in the vertical static and/or the conveyor blender, was explored using the discrete element method (DEM) approach. The blending quality of limestone fine aggregate fractions binary mixture for application in self-compacting concrete was studied. The potential of augmenting the conveyor mixer working efficiency by joining its operation to a Komax-type vertical static mixer, to increase the blending conduct was investigated. In addition the impact of the feed height on the flow field in the cone-shaped conveyor mixer was examined using the DEM simulation. Applying the numerical approach enabled a deeper insight into the quality of blending actions, while the relative standard deviation criteria ranked the uniformity of the mixture. The primary objective of this investigation was to examine the behavior of mixture for two types of blenders and to estimate the combined blending action of these two mixers, to explore the potential to augment the homogeneity of the aggregate fractions binary mixture, i.e., mixing quality, reduce the blending time and to abbreviate the energy-consuming
Quality evaluation of cold-pressed oils and semi-defatted cake flours obtained on semi-industrial scale
No full textMechanically pressed oils and the remaining semi-defatted cake flours obtained from fruit, vegetables and some of less utilized oilseeds have increasing trend on global oil market due to their health benefits and cost-effectiveness. Cold-pressed oils obtained from various plant seeds were evaluated in terms of physico-chemical properties, fatty acid composition and functional quality properties. Low oil yield was obtained for berry, red grape and sour cherry oils while moderate or high yield was obtained for other plant materials. Oil samples contained high amounts of unsaturated fatty acids, with linoleic and oleic acids as the major acids. Among all oils, flaxseed, raspberry and blackberry seed oils contained significant amounts of alpha-linolenic acid. In terms of functional quality indices, berry seed oils exhibited the highest quality of all obtained cold-pressed oils. Residual semi-defatted cake flours were examined in terms of basic proximal analysis. Poppy, sesame, flaxseed and both pumpkin flours had moderate or high contents of crude proteins and low content of fibres. Sour cherry, blackberry, raspberry and red grape flours had high fibre contents and relatively low content of proteins. A comprehensive study of oils and their residual cakes obtained from by-products of fruit and vegetable processing industry supports the concept of zero waste technology
Identification of biomarkers in hydrosoluble extracts from spelt and wheat cultivated in different production systems
No full textBACKGROUND In the present paper, a method for differentiation between common and spelt wheat grown in different farming systems (biodynamic, ecological, integrated, conventional), based on biomarkers identified from aqueous flour extracts (nitrogen and 14 soluble carbohydrates) was employed. RESULTS The identification and determination of soluble carbohydrate content were carried out using gas chromatography-mass spectrometry, with the UV spectrum generated by mass spectrometry for comparison with the WILEY database. Soluble carbohydrates were determined in the peak area between 21.92 and 43.63 min(-1) retention time. The obtained data set was analyzed by multivariate statistical techniques. It was revealed that common wheat exerted a much more pronounced tendency than spelt wheat to be influenced by the farming system. CONCLUSION This differentiation was particularly well visualized after subjecting the data set to principal component analysis (PCA) and cluster analysis (CA). In the PCA graph, all spelt samples were positioned closer to the corresponding control sample, in contrast to the wheat samples, which were distributed over a huge area in the factor space. CA showed that the spelt samples grown under different farming systems were highly similar and grouped into one cluster. Common wheat samples cultivated under organic, biodynamic and integrated system were similar and represented the second cluster, whereas that cultivated under the conventional system was clearly separated from other samples
Weather Conditions Influence on Hyssop Essential Oil Quality
No full textThis paper is a study of the chemical composition of Hyssopus officinalis ssp. officinalis grown during three years (2017-2019) at the Institute of Field and Vegetable Crops Novi Sad (Vojvodina Province, Serbia). Furthermore, comparisons with ISO standards during the years were also investigated, as well as a prediction model of retention indices of compounds from the essential oils. An essential oil obtained by hydrodistillation and analysed by GC-FID and GC-MS was isopinocamphone chemotype. The gathered information about the volatile compounds from H. officinalis was used to classify the samples using the unrooted cluster tree. The correlation analysis was applied to investigate the similarity of different samples, according to GC-MS data. The quantitative structure-retention relationship (QSRR) was also employed to predict the retention indices of the identified compounds. A total of 74 experimentally obtained retention indices were used to build a prediction model. The coefficient of determination for the training cycle was 0.910, indicating that this model could be used for the prediction of retention indices for H. officinalis essential oil compounds
The characterization and pollution status of the surface sediment in the Boka Kotorska Bay, Montenegro
No full textSurface sediments collected from twelve stations in the Boka Kotorska Bay were analyzed for the level and distribution of twenty-six elements and ten oxides, grain sizes, organic matter, and carbonate content. Potentially toxic elements (Al, Fe, Mn, Cr, Zn, Ni, Cu, Pb, As, Co, U) were determined to assess the contamination status and potential environmental risk according to the single-element indices (enrichment factor (EF), geoaccumulation index (Igeo), contamination factor (CF)), and combined index (pollution load index (PLI)). The single-element indices EF and CF revealed that the surface marine sediment was moderately polluted with Pb, Cu, and Cr, while Igeo indicated moderate pollution with Ni > Cr > Zn > Cu > As and moderate to heavy pollution with Pb, as a result of the anthropogenic factors. The method of the combined effect of toxic elements, PLI, showed the highest pollution rate at the shipyard location in the Bay of Tivat. Pearson's correlation coefficient (r), principal component analysis (PCA), and cluster analysis (CA) were applied to highlight similarities and differences in the distribution of the investigated elements in the Bay, confirming the claim obtained by the pollution indices. The sediment contamination with most heavy metals, such as Cr, Zn, Ni, Cu, Pb, and As, has been identified in the Tivat Bay area
In Vitro Study of Two Edible Polygonoideae Plants: Phenolic Profile, Cytotoxicity, and Modulation of Keap1-Nrf2 Gene Expression
No full textPolygonum aviculare and Persicaria amphibia (subfam. Polygonoideae) are used in traditional cuisines and folk medicine in various cultures. Previous studies indicated that phytochemicals obtained from Polygonoideae plants could sensitize chemoresistant cancer cells and enhance the efficacy of some cytostatics. Here, the cytotoxic properties of chemically characterized ethanol extracts obtained from P. aviculare and P. amphibia, individually and in combination with doxorubicin (D), were determined against hepatocarcinoma HepG2 cells. Phenolic composition, cell viability, cell cycle, apoptosis, and the expression of Keap1 and Nrf2 were examined by following methods: LC-MS/MS, LC-DAD-MS, MTT, flow cytometry, and qRT-PCR. Extracts were rich in dietary polyphenolics. Synergistic cytotoxicity was detected for extracts combined with D. The observed synergisms are linked to the interference with apoptosis, cell cycle, and expression of Keap1-Nrf2 genes involved in cytoprotection. The combined approach of extracts and D could emerge as a potential pathway of chemotherapy improvement
Artificial neural network prediction of microbiological quality of beef minced meat processed for fast-food meals
No full textIn this study, the microbiological quality of 72 minced beef meat samples collected during six months from a local butcher was defined after laboratory analysis and developing advanced mathematical models. This new simultaneous approach provided adequate precision for the prediction of the microbiological profile of minced beef meat as one of the easily spoiled products with a short shelf life. For the first time, an artificial network model was developed to predict the microbiological profile of beef minced meat in a fast-food restaurant according to meat and storage temperatures, butcher identification, and work shift. A concurrent statistical study of practical analysis and the developing mathematical models provided adequate precision for the prediction of the microbiological profile of minced beef meat. The developed ANN provided a good prediction of the microbiological profile of beef minced meat with an overall R2 of 0.867 during the training cycle
Chemical composition of hyssop cv. 'Domaći ljubičasti' essential oil and its antimicrobial activity
No full textMiloduh (Hyssopus officinalis L., Lamiaceae) je višegodišnji žbun ili polužbun aromatičnog i oštrog mirisa zbog čega se koristi kao začinska biljka. Takođe je i ukrasna i medonosna biljka, ali i tradicionalni lek za bolesti organa za disanje i kod poremećaja varenja. Miloduh je cenjena eterično-aromatična biljka, a etarsko ulje se koristi u farmaceutskoj, parfimerijskoj i kozmetičkoj industriji kao i aromaterapiji. Cilj ovog istraživanja je bio da se determiniše hemijski sastav etarskog ulja miloduha kultivara "Domaći ljubičasti" gajenog u Srbiji, i da se ispita antimikrobna aktivnost na 16 bakterija, uglavnom patogena u prehrambenoj industriji. Ukupno 61 komponenta je detektovana u etarskom ulju, pri čemu su monoterpenski ketoni CIS-pinokamfon (43.8%) i trans-pinokamfon (18.3%) bili najzastupljeniji, čineći 62.1%, a potom slede b-pinen i pinokarvon. Etarsko ulje miloduha je ispoljilo antibakterijsku aktivnost na: Staphylococcus aureus, Escherichia coli, Bacillus cereus, Proteus hauseri, Listeria monocytogenes, Rhodococcus equi, Listeria ivanovii, Salmonella Enteritidis, Enterococcus faecalis, Listeria innocua i Bacillus spizizenii, dok nije delovalo na Pseudomonas aeruginosa, Salmonella Typhimurium, Klebsiella aerogenes i Staphylococcus epidermidis.Hyssop (Hyssopus officinalis L., Lamiaceae) is a perennial shrub or subshrub violet-blue flowers in verticillasters and spicy taste with a pungent flavour. Besides being used as a culinary herb for flavouring and food preservation, this plant is also an ornamental, bee attracting plant and a traditional remedy for respiratory diseases and digestive disturbances. Hyssop is an essential oil-bearing plant, and its essential oil (Hyssopi aetheroleum) is used in the pharmaceutical, perfume and cosmetics industries as well as in aromatherapy. The objective of this study was to determine the chemical composition of essential oil of hyssop CV. "Domaći ljubičasti", grown in Serbia, and investigate its antimicrobial activity against 16 bacteria, mainly pathogens in the food industry. A total of 61 compounds were detected in the hyssop essential oil. The bicyclic monoterpene ketones CIS-pinocamphone (43.8%) and trans-pinocamphone (18.3%) were the most abundant, comprising 62.1%, followed by b-pinene (6.3%) and pinocarvone (6.1%). Hyssop essential oil expressed antibacterial activity against: Staphylococcus aureus, Escherichia coli, Bacillus cereus, Proteus hauseri, Listeria monocytogenes, Rhodococcus equi, Listeria ivanovii, Salmonella Enteritidis, Enterococcus faecalis, Listeria innocua and Bacillus spizizenii. Hyssop essential oil did not express antibacterial activity against Pseudomonas aeruginosa, Salmonella Typhimurium, Klebsiella aerogenes and Staphylococcus epidermidis. Results of this study show that hyssop essential oil has potential for using as natural supplement for control of foodborne diseases of microbiological origin, as well as flavor compositions (herbaceous, camphor-like odour with warm and spicy undernotes), especially for meat products, sauces, soups and seasonings