Extraction of steviol glycosides from dried Stevia rebaudiana by pressurized hot water extraction

In existing processes, the extraction of steviol glycosides from stevia leaves involves many process steps often including extraction by organic solvents. The purpose of the present study was to develop a process for the effective extraction of steviol glycosides, which can provide a concentrated juice exhibiting a high level of recovery with regard to the target compounds, rebaudioside A and stevioside. Pressurized Hot Water Extraction (PHWE) was first optimized with Response Surface Methodology in terms of maximized rebaudioside-A yield and minimized colour components. PHWE was then combined with pressing in a wine-press, resulting higher efficiency for extracting both steviol glycosides in comparison to the reported methods in the literature. Finally, spray drying was applied for both product stabilization and removal of contaminants

Antibacterial effect of sprouts against human pathogens in vitro

Sprouts contain minerals, vitamins, and other compounds, which may have antimicrobial activity. Antimicrobial compounds are released from homogenized sprouts and diffuse into the culture medium inhibiting the growth of pathogenic bacteria. These antibacterial compounds may influence the multiplication of contaminating pathogens. In this study the antimicrobial effects of 55 different homogenized sprouts were investigated with agar well diffusion method on human pathogenic bacteria. Homogenizates of different radish, early kohlrabi, and red cabbage sprouts caused inhibitory zone around the wells on the surface of inoculated agar plates. Mustard, zucchini, medical (German) chamomile, spicy fenugreek, and adzuki bean sprouts had antimicrobial effect only against a few human pathogenic bacteria. Twenty-nine other spicy and vegetable sprouts had no antibacterial activity against the investigated human pathogens. The results suggest that a few sprouts have antimicrobial properties, but different cultivars of the same species have different effects against different bacterial strains. The sprouts of radish cultivars contained the most effective antibacterial compounds

Consolidated microcapsules with double alginate shell containing paraffin for latent heat storage

Double-shell alginate microcapsules containing paraffin phase change material (PCM) were prepared for latent heat storage by a method of repeated interfacial coacervation/crosslinking. The proposed process consisted of three main steps: (1) preparation of paraffin containing core particles by dripping an O/W emulsion of melted paraffin and aqueous sodium alginate into a calcium chloride ionic cross-linking solution, (2) encapsulation of the core particles into double alginate shell by ionic gelation/crosslinking by repeated interactions between the sodium alginate and calcium chloride solutions, and (3) consolidation of the capsule shells by contact heat treatment. The effects of process parameters such as the sodium alginate concentration, the calcium chloride concentration in certain stages of the process, and the contact time between the formed core particles and the surrounding alginate solution on the paraffin content and the mean diameter of capsules were studied by experimental design and statistical evaluations. The prepared PCM capsules had uniform sizes, core/shell structure, double-walled non-porous alginate coating, tunable void space inside the core, and suitably high paraffin content at properly selected process conditions, corresponding to 95.0 J/g melting and 91.7 J/g freezing latent heat capacity. Thermogravimetric analysis and repeated thermal cycling evidenced good thermal stability, and proper mechanical strength for leakage free microcapsules

Successful surgical intervention in a case of spontaneous chylothorax in an infant unresponsive to conservative therapy

L

Effects and changes of zearalenone and fumonisin contamination in corn-based bioethanol process

Bioethanol production is a growing industry nowadays. In this work dry-grind ethanol production was carried out from different corn samples (uncontaminated; zearalenone; fumonisin B1+B2 contaminated) and the changes of the ratio of the solid-liquid phase as well as toxin concentrations were examined in laboratory scale. The ethanol yields of mycotoxincontaminated corn-mashes were 27% lower, due to 10% less produced glucose-concentrations from these raw materials, compared to uncontaminated ones. By the end of the whole process, the initial 20% solid content was reduced below 7% both in contaminated and uncontaminated corn-mashes. Differences were observed in the concentration changes of examined toxins. Zearalenone was localized in the solid phase, and its concentrations did not alter during the ethanol production process. Fumonisin concentration increased 3 times at the end of the process, and it dissolved in the liquid phase in significant amount

Middle Bronze Age humidity and temperature variations, and societal changes in East-Central Europe

Archaeological evidence points to substantial changes in Bronze Age societies in the European-Mediterranean region. Isotope geochemical proxies have been compiled to provide independent ancillary data to improve the paleoenvironmental history for the period of interest and support the interpretation of the archaeological observations. In addition to published compositions, in this study we gathered new H isotope data from fluid inclusion hosted water from a stalagmite of the Trió Cave, Southern Hungary, and compared the H isotope data with existing stable isotope and trace element compositions reported for the stalagmite. Additionally, animal bones and freshwater bivalve shells (Unio sp.) were collected from Bronze Age archaeological excavations around Lake Balaton and their stable C and O isotope compositions were measured in order to investigate climate changes and lake evolution processes during this period. The data indicate warm and humid conditions with elevated summer precipitation around 3.7 cal ka BP (Before Present, where present is 1950 CE), followed by a short-term deterioration in environmental conditions at about 3.5 cal ka BP. The environment became humid and cold with winter precipitation dominance around 3.5 to 3.4 cal ka BP, then gradually changed to drier conditions at ∼3.2 cal ka BP. Significant cultural changes have been inferred for this period on the basis of observations during archaeological excavations. The most straightforward consequences of environmental variations have been found in changes of settlement structure. The paleoclimatological picture is well in line with other East-Central European climate records, indicating that the climate fluctuations took place on a regional scale