RIOFH - Repository of Institute of General and Physical Chemistry
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Exploring consumer preferences and factors associated with vegetable consumption
No full textU cilju povećanja potrošnje povrća i pružanja korisnih infromacija potrošačima, analizirane su njihovi stavovi kao i razlozi koji utiču na konzumaciju ovih namirnica. Da bi se ostvario uvid u opšte karakteristike potrošnje povrća korišćen je online upitnik, a istraživanje je sprovedeno na uzorku od 711 slučajno izabranih ispitanika. Za utvrđivanje stavova potrošača o svežem i prerađenom povrću upotrebljena je analiza korespondencije. Rezultati su pokazali da potrošači povrće smatraju ukusnim, lakim za upotrebu i zdravim, dok se glavni nedostaci odnose na bezbednost, kratak rok trajanja i visoku cenu ovih namirnica. Kako bi se povećala potrošnja svežeg i prerađenog povrća, potrebno je da postoje posebno dizajnirane promotivne kampanje koje bi isticale njihove prednosti i doprinos zdravstvenom stanju pri svakodnenvoj konzumaciji. Rezultati dobijeni ovom studijom pružaju uvid u trenutno stanje ponašanja potrošača u Srbiji i mogli bi biti korisni za kreiranje specifičnih promotivnih programa i strategija komunikacije, kako bi uticali na povećanje znanja potrošača o značaju povrća u ishrani. Kampanje treba da budu usmerene ka podizanju svesti potrošača o dobrobiti svakodnevne konzumacije povrća čime bi se poboljšalo opšte zdravstveno stanje populacije i ujedno smanjili troškovi lečenja sve više prisutnih masovnih hroničnih bolesti izazvanih neadekvatnom ishranom.The consumers' preferences and their reasons for vegetable consumption were examined with the aim to provide useful information to increase the consumption of these food items. Consumers' general viewpoints about vegetable consumption were examined using an online questionnaire. The study was conducted on a sample of 711 respondents chosen randomly and obtained data were analyzed by the correspondence analysis. Results suggest that consumers consider vegetables as tasty, easy to use and healthy for consumption. The main drawbacks for vegetable consumption are safety issues, short shelf-life and high price. In order to increase the consumption of these foodstuffs, each type of fresh and processed vegetable should have a specifically designed campaign, emphasizing its specific attribute. Obtained results might provide an insight into the current state of consumers' behavior in Serbia and might be useful for creating specific promotional programs and more appropriate communication strategies aiming to increase consumers' knowledge about the importance of regular vegetable consumption. They should raise consumers' awareness by emphasizing the importance of adequate daily vegetable consumption. This, in turn, should improve public health and reduce the health and economic costs of massive chronic diseases caused by inadequate diet
Antimicrobial nanoparticles and biodegradable polymer composites for active food packaging applications
No full textThe food industry faces numerous challenges to assure provision of tasty and convenient food that possesses extended shelf life and shows long-term high-quality preservation. Research and development of antimicrobial materials for food applications have provided active antibacterial packaging technologies that are able to meet these challenges. Furthermore, consumers expect and demand sustainable packaging materials that would reduce environmental problems associated with plastic waste. In this review, we discuss antimicrobial composite materials for active food packaging applications that combine highly efficient antibacterial nanoparticles (i.e., metal, metal oxide, mesoporous silica and graphene-based nanomaterials) with biodegradable and environmentally friendly green polymers (i.e., gelatin, alginate, cellulose, and chitosan) obtained from plants, bacteria, and animals. In addition, innovative syntheses and processing techniques used to obtain active and safe packaging are showcased. Implementation of such green active packaging can significantly reduce the risk of foodborne pathogen outbreaks, improve food safety and quality, and minimize product losses, while reducing waste and maintaining sustainability
Laser Processing of Ni-Based Superalloy Surfaces Susceptible to Stress Concentration
No full textReliable and resilient constructions are basic for ensuring the safety of various structures. The superalloys are used as constructive materials due to their superb mechanical properties and endurance. However, even these materials can have certain areas where the stress concentration is higher than expected, such as drilling holes, which are common in various structures that need additional enhancement. Surface laser modifications of the areas surrounding the holes drilled in Nimonic 263 sheets are done by pulsed picosecond and nanosecond Nd:YAG laser irradiations with pulse durations of 170 ps and LT = 8 ns, respectively. Following the laser surface treatment, the effectiveness of the enhancement was analyzed by the microhardness test and the deformation test. The results show that the deformation and stress values are decreased by 25-40 percent, showing the improvement in the resilience to deformation. The Vickers microhardness test results indicate an improvement in the Nimonic 263 microhardness. The dimensions of the microcracks are higher for the untreated material in comparison to the laser-treated material
Comprehensive Profiling of Microbiologically Induced CaCO3 Precipitation by Ureolytic Bacillus Isolates from Alkaline Soils
No full textMicrobiologically induced CaCO3 precipitation (MICP) is a well-known bio-based solution with application in environmental, geotechnical, and civil engineering. The significance of the MICP has increased explorations of process efficiency and specificity via natural bacterial isolates. In this study, comprehensive profiling of five soil ureolytic Bacillus strains was performed through a newly formed procedure that involved six steps from selection and identification, through kinetic study, to the characterization of the obtained precipitates, for the first time. To shorten the whole selection procedure of 43 bioagents with the MICP potential, Standard Score Analysis was performed and five selected bacteria were identified as Bacillus muralis, B. lentus, B. simplex, B. firmus, and B. licheniformis by the MALDI-TOF mass spectrometry. Despite following the targeted activity, kinetic studies were included important aspects of ureolysis and the MICP such as cell concentration, pH profiling, and reduction in calcium ion concentration. At the final step, characterization of the obtained precipitates was performed using FTIR, XRD, Raman, DTA/TGA, and SEM analysis. Although all tested strains showed significant potential in terms of precipitation of calcite or calcite and vaterite phase, the main differences in the MICP behavior can be observed at the bacterial strain level. B. licheniformis showed favorable behavior compared to the reference Sporosarcina pasteurii DSM 33
Effects of Agaricus bisporus Mushroom Extract on Honey Bees Infected with Nosema ceranae
No full textNosema ceranae affects honey bee (Apis mellifera L.) causing nosemosis disease that often induces serious problems in apiculture. Antibiotic fumagillin is the only licenced treatment against nosemosis, but its effectiveness is questioned and its usage associated with risk of bee mortality and appearance of residues in bee products. In search for alternative treatment for the control of nosemosis, water crude extract of Agaricus bisporus was tested on bees in laboratory (cage) experiments. Bee survival and food consumption were monitored together with Nosema infection level and expression of five genes (abaecin, hymenoptaecin, defensin, apidaecin, and vitellogenin) were evaluated in bees sampled on days 7 and 15. Apart from the gene for defensin, the expression of all tested genes was up-regulated in bees supplemented with A. bisporus extract. Both anti-Nosema and immune protective effects of A. bisporus extract were observed when supplementation started at the moment of N. ceranae infection or preventively (before or simultaneously with the Nosema infection) Agaricus bisporus water crude extract was tested on honey bees for the first time. The first part of the cage experiment was set for selecting one concentration of the A. bisporus extract. Concentration of 200 mu g/g was further tested in the second part of the experiment where bee survival and food consumption were monitored together with Nosema infection level and expression of five genes (abaecin, hymenoptaecin, defensin, apidaecin, and vitellogenin) that were evaluated in bees sampled on days 7 and 15. Survival rate of Nosema-infected bees was significantly greater in groups fed with A. bisporus-enriched syrup compared to those fed with a pure sucrose syrup. Besides, the anti-Nosema effect of A. bisporus extract was greatest when applied from the third day which coincides with the time of infection with N. ceranae. Daily food consumption did not differ between the groups indicating good acceptability and palatability of the extract. A. bisporus extract showed a stimulative effect on four out of five monitored genes. Both anti-Nosema and nutrigenomic effects of A. bisporus extract were observed when supplementation started at the moment of N. ceranae infection or preventively (before or simultaneously with the infection)
Sample analysis of organically produced honey and conventionally produced honey in Western Serbia
No full textNa području Zapadne Srbije izuzetno je zastupljena proizvodnja meda na konvencionalni način. Uprkos prednostima koje donosi organska proizvodnja meda, pčelari se ipak, ne odlučuju na taj korak, bez obzira na teškoće sa plasmanom na inostrano tržište. Osim neospornih nutritivnih vrednosti, med proizveden na konvencionalni način, uz upotrebu agrotehničkih mera i primenu široke palete proizvoda za tretiranje bolesti pčela, u svom sastavu vrlo često sadrži i ostatke opasnih hemijskih jedinjenja, pesticida i antibiotika. Istraživanje je vršeno na području Zapadne Srbije. Obuhvaćeno je pet proizvođača meda, dva koja proizvodnju vrše na organski način i tri sa konvencionalnim načinom rada. Nakon osmatranja terena i pčelinjaka, intervjuisanja proizvođača, uzeti su uzorci meda. Po izvršenim analizama, konstantovano je da je jedan uzorak iz konvencionalne proizvodnje nebezbedan za ljudsku upotrebu, jer sadrži ostatke pesticida - amitraza.Conventional method of honey production is widely spread in the area of western Serbia. Despite the advantages of honey production in an organic manner, beekeepers are still hesitant to take this step, regardless of the difficulties with placement of such honey on the foreign market, so their products are mainly sold on the domestic market. Besides the undeniable nutritional value, honey produced in the conventional way with proper use of agro technical measures and implementation of the wide range of products in the treatment of bee diseases, in its composition very often contain residues of hazardous chemical compounds, pesticides, antibiotics. Research on four qualitative differences of the content of certain substances between the conventional and organic honey producers has been conducted in western Serbia. The research obtained five manufacturers, out of which two were engaged in organic manner of production, while the remaining three dealt with the conventional honey production. After examining the area and the apiaries in question, interviews with honeybee producers, the sampling of honey took place. Upon performed analysis, it was concluded that one conventionally produced sample of honey was not safe for human consumption, due to presence of pesticides
In vitro antioxidant, antihyperglycemic, anti-inflammatory, and antimicrobial activity of Satureja kitaibelii Wierzb. ex Heuff. subcritical water extract
No full textAs the main goal of this study was the verification of Satureja kitaibelii Wierzb. ex Heuff. in form of the crude extract obtained by subcritical water extraction (SWE) technique in terms of polyphenolic composition, in vitro antioxidant capacity, antihyperglycemic, and anti-inflammatory activities as well as an antimicrobial effect against 10 microorganisms. HPLC analysis showed the presence of ten compounds in a total concentration of 89.33 mg/g of the SWE extract, and demonstrated that subcritical water polarity was the most selective for extracting syringic and caffeic acid, as well as epicatechin (37.88 18.06, and 10.04 mg/g, respectively), while flavonoids like rutin, luteolin, and apigenin were present in low concentration ( LT 2 mg/g). Results of antioxidant activity assays revealed that superoxide anion and ABTS center dot+ radical models expressed the highest scavenging abilities (437.35 and 412.09 mu mol TE/g, respectively), followed by lipid radicals (69.61 mu mol TE/g), and DPPH center dot (32.28 mu mol TE/g), while in the case of ferric ion reducing ability was noted a high value (118.19 mu mol TE/g). S. kitaibelii SWE was less efficient in the antihyperglycemic assay (AhgA = 30.72 %), but the high antiinflammatory activity of S. kitaibelii SWE was observed (30.35 %). The antimicrobial activity was demonstrated against Bacillus cereus, Staphylococcus aureus, Enterococcus faecalis, Listeria monocytogenes as well as Saccharomyces cerevisiae, Candida albicans, and Aspergillus brasiliensis through antimicrobial screening, minimal inhibitory concentration, and pharmacodynamics study
Impact of plum processing on the quality and oxidative stability of cold-pressed kernel oil
No full textPlum kernels of the "Cacanska rodna" variety, by-products from plum brandy production, were collected before and after fermentation and distillation, and used for cold-pressed oil production. Fatty acid and tocopherol contents were determined by capillary GC and HPLC, while the oxidation stability of the resulting cold-pressed oils was tested by the Rancimat method. The results showed that oleic fatty acid was dominant in the oil samples with a content of 56.6 to 61.8%, regardless of the plum kernels' origin. The fermentation and distillation processes had a pronounced effect on the tocopherol content and oxidative stability of the resulting kernel oils. Tocopherol contents were 61.8 mg.100g(-1), 87.4 mg.100g(-1), 79.6 mg.100g(-1) of oil, while the induction periods were 38.7, 44.4 and 33.6 hours for samples before fermentation, after fermentation and distillation, respectively. Based on the results, it could be concluded that the fermentation process increased the content of tocopherols in kernel oil whereas the high temperature during the distillation process adversely affected the tocopherol content and oxidative stability of the obtained kernel oil
Switching on near-infrared light in lanthanide-doped CsPbCl3 perovskite nanocrystals
No full textThe accessible emission spectral range of lead halide perovskite (LHP) CsPbX3 (X = Cl, Br, I) nanocrystals (NCs) has remained so far limited to wavelengths below 1 mu m, corresponding to the emission line of Yb3+, whereas the direct sensitization of other near-infrared (NIR) emitting lanthanide ions is unviable. Herein, we present a general strategy to enable intense NIR emission from Er3+ at similar to 1.5 mu m, Ho3+ at similar to 1.0 mu m and Nd3+ at similar to 1.06 mu m through a Mn2+-mediated energy-transfer pathway. Steady-state and time-resolved photoluminescence studies show that energy-transfer efficiencies of about 39%, 35% and 70% from Mn2+ to Er3+, Ho3+ and Nd3+ are obtained, leading to photoluminescence quantum yields of similar to 0.8%, similar to 0.7% and similar to 3%, respectively. This work provides guidance on constructing energy-transfer pathways in semiconductors and opens new perspectives for the development of lanthanide-functionalized LHPs as promising materials for optoelectronic devices operating in the NIR region
Supercritical Fluid Extraction Kinetics of Cherry Seed Oil: Kinetics Modeling and ANN Optimization
No full textThis study was primarily focused on the supercritical fluid extraction (SFE) of cherry seed oil and the optimization of the process using sequential extraction kinetics modeling and artificial neural networks (ANN). The SFE study was organized according to Box-Behnken design of experiment, with additional runs. Pressure, temperature and flow rate were chosen as independent variables. Five well known empirical kinetic models and three mass-transfer kinetics models based on the Sovova's solution of SFE equations were successfully applied for kinetics modeling. The developed mass-transfer models exhibited better fit of experimental data, according to the calculated statistical tests (R-2, SSE and AARD). The initial slope of the SFE curve was evaluated as an output variable in the ANN optimization. The obtained results suggested that it is advisable to lead SFE process at an increased pressure and CO2 flow rate with lower temperature and particle size values to reach a maximal initial slope