Green synthesis of hydroxyapatite (HA) nanoparticles was followed using various concentrations of pectin extracted from the culinary banana bract. The effect of pectin concentrations on purity, crystallinity, particle size, and morphology of synthesized HA nanoparticles were studied. The extracted pectin was characterized by proton-1 nuclear magnetic resonance spectroscopy (1H NMR) and Fourier transform infrared (FT-IR) spectroscopy. FT-IR results revealed that increased concentration (0–0.075 % w/w) of pectin substantially improved the purity level of synthesized HA nanoparticles. In addition, higher concentration of pectin also reduced the crystallinity and size of the synthesized HA nanoparticles, which was confirmed by X-ray diffraction (XRD) and SEM results, respectively. The synthesized HA nanoparticles at increased pectin concentration (HA0.075) evinced high purity, less crystallinity, and discrete uniform shape. Results of TEM images have the credence to reveal the presence of nanosized discrete particles (20–50 nm) with lattice structure of hydroxyapatite.
The analyzed samples were runoff waters from bituminous roofing. The runoff water pH was lower than that of the storm-water. First flush phenomena were observable in the samples conductivity, turbidity as well as suspended solid, dry and organic matter concentration. The reason of the phenomena is the initial dissolution of deposited aerosols and weathering products. Because of that, the roof runoff quality is affected by the dry period length. Presumably to the roof matter, the samples had high dissolved organic matter concentrations. The measured polycyclic aromatic hydrocarbon (PAH) concentration implied the dissolution of some component from the roof matter.
The objective of this work was to assess the impact of various NaCl concentrations on Lactobacillus rhamnosus OXY viability after freeze-drying. Osmotic stress was applied during the exponential growth phase of bacterial culture. At salt concentrations between 0.2–0.5 M, a high biomass concentration and a significant increase in cell viability after lyophilisation was observed. An analysis of two-dimensional protein gels indicated the presence of shock proteins, for example, GroEL, ClpB, DnaK, TF, which provide resistance during freeze-drying and subsequent storage. On the basis of these results, it is recommended that lactic acid bacteria cultures be sub-lethally treated with 0.5 M NaCl before freeze-drying.
The degradation process of fructo-oligosaccharides (Raftilose® P95) has been studied in apple pulp matrix at 70–80 °C in pH range 2.7–3.3. Changes of sugar compositions have been analysed by an appropriate isocratic HPLC with differential refractive index detector for oligosaccharide determination. According to Arrhenius equation significant effect of temperature has been observed on the decrease of oligomer concentration. The oligomers (DP3-DP7) degrade continuously at any pH between 2.7 and 3.3. The lower the pH the higher the change of oligomer and monomer concentration is. The oligomers (DP4-DP7) could give out in 30–40 min below pH 3.0 caused by the high concentration of protons. The rate of degradation depends not only on the processing time, temperature, and the proton concentration of the solution, but on the characteristic of apple pulp, too, where the degradation is significantly higher than that in water solution.
Authors:D. Varga, Zs. Sándor, Cs. Hancz, I. Csengeri, Zs. Jeney, and Zs. Papp
The aim of our study was to survey the geosmin (GSM) and 2-methylisoborneol (MIB) concentrations of the sediment and that of common carp (Cyprinus carpio) flesh in three different Hungarian fish farms (clayey, marshy, and sodic ponds).
Results showed that the concentrations of off-flavour compounds of the sediment and fish fillets were related to the natural environment. The GSM concentration of bottom soil samples was higher, than MIB in each fish farm. Both off-flavour compounds were the highest in the marshy fish pond and the lowest in the sodic pond. In case of fish flesh, significant differences were found between the farms in GSM level and fat content. In the fish flesh the same tendency was found as in the sediments, but surprisingly, MIB concentration was higher in the fillets, referring to accumulation.
Authors:K.G. Mladenović, M.Ž. Muruzović, and L.R. Čomić
In this study, the effects of different temperature, pH, salt and glucose concentrations on the planktonic growth, biofilm formation, and formed biofilm of Serratia odorifera and Serratia marcescens, isolated from traditionally made cheese, were investigated using spectrophotometric method. The investigated strains demonstrated best planktonic growth and biofilm formation in Tryptic soy broth. The limiting factors for the planktonic growth and biofilm formation were temperature below 4 °C and salt concentration above 4%. Temperature of 37 °C and 44 °C, as well as various concentrations of glucose, stimulated the planktonic growth of bacteria. Moderate influence on biofilm formation was demonstrated at 37 °C as well as at various concentrations of glucose. These results were in accordance with the origin of bacteria, since the isolates were obtained from cheese.
The adaptation to brining conditions of 20 strains of Lactobacilli were tested. At 6% salt all strains reduced the pH to 4 in 72 h. At higher salt concentration, only some of the strains showed this ability. The ability to synthesise lactic acid was tested at different salt concentrations. Lactic acid was quantified by HPLC analyses and at halophilic conditions six strains showed good ability. The glucosidic activity tested on a synthetic compound (
-nitrophenyl-β-D-glucopyranoside) screened the best
strains (20205 DSMZ, 20314 DSMZ and 104442 CIP). The ability to hydrolyse the oleuropein molecule was tested and all of the strains selected showed good activity at low salt concentration and low oleuropein content in the medium. This ability decreased drastically when the salt and oleuropein content were higher. The best strain was the 20205 DSMZ, which at low salt concentration hydrolysed more than 95% of oleuropein in 120 h.
Changes of volatile compounds of noni juice during the traditional process of fermentation/aging was studied by means of HS-SPME and GC-MS. Major acids, octanoic and hexanoic, diminished their concentration; while esters of ethanol, 1-butanol and 1-hexanol, with their flavour fruity notes, increased. The concentration of esters of methanol and 3-methyl-3-buten-1-ol decreased during the fermentation/aging process, whereas major alcohols of noni juice, 1-hexanol and 1-octanol, increased their concentration during the process. During the 60 days of the process the volatile composition of the noni juice had reached stability. These chemical changes justify that fermented juice possesses a flavour less pungent than fresh juice due to an important decrease in the hexanoic and octanoic contents, as well as a greater fruity note due to the increment in ester concentrations.
Chelidonii herba has long been known in herbal medicine for its choleretic, cholagogue, spasmolytic and antiviral activities. It is important to monitor the amount of mineral elements in Chelidonii herba preparations consumed mainly for their phytotherapeutical effects. In addition to organic compounds, dissoluble mineral elements in the teas and tinctures of herbs may also have a role in therapy. The concentration of 24 elements (Al, As, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Mo, Na, Ni, P, Pb, S, Ti, V, Zn) in crude drugs (herb and root), in their aqueous solutions (infusion, decoction) and alcoholic extracts were studied by ICP-OES. The difference between the concentration of elements in extracts - except for copper, manganese and sodium - was highly significant. It has been found that the root contains higher concentrations of mineral elements except for boron, copper, phosphorus and sulphur. The infusion contained most elements in the highest concentration and proved to be the best source for obtaining minerals. The same tendency was observed in the case of dissolutions. In aqueous extracts, the dissolution of mineral elements was between 10% and 65% for most elements, especially for potassium (65%) and phosphorus (54%). The dissolution of mineral elements in the case of tinctures decreased with increasing alcohol concentration. It may be stated that the presence of macro- and microelements in extracts greatly contribute to their therapeutical value.
Authors:B. Vecseri-Hegyes, P. Fodor, and Á. Hoschke
The most sensitive and time-consuming technological step of beer production is the fermentation of wort. Problems during fermentation will not only prolong production time but it will lead to the deterioration of beer quality. Most often it is due to low zinc concentration of the wort or the yeast. Due to lack of zinc the fermentation lasts longer, composition of fermentation by-products changes, maltose intake slows down, sedimentation ability and heat sensitivity of the yeast increase. In Part I of our work, the factors affecting the degree of zinc supply of wort were examined. During the examination of zinc supply of wort two kinds of beer were produced: all-malt beer and beer with adjunct. Change of zinc concentration was followed throughout the brewing process at every technological step. It was found that concentration of zinc gradually decreases during production of wort, and only a small fraction of the calculated amount appears in it. Wort made with adjunct has even lower zinc concentration than all-malt wort. In all malt wort 3.4%, while in wort containing adjunt only 0.4% of the zinc appeared in the wort. Yeast can absorb only the ionic form of zinc during fermentation, thus we had elaborated a method for the separation of the organic and inorganic form of zinc, which was followed by the determination of the concentration of ionic zinc in wort prior to fermentation.