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.
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: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.
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.
The protein content, solubility and functional properties of a total protein concentrate prepared from the seeds of
Roxb. were determined. The effects of pH and/or NaCl concentration on some of these functional properties were also investigated. The protein content of the seed protein concentrate was found to be 65.88%. The minimal protein solubility was observed at pH 4 and the maximum was at pH 12. Water- and oil-holding capacities of the seed protein concentrate were 2.77 g g
and 5.79 g g
, respectively. The emulsifying activity and emulsion stability, as well as foaming capacity and foam stability, were greatly affected by pH levels and salt concentrations. Lower values were observed at slightly acidic pH (pH 4.0) and high salt concentration. Total protein concentrate was highly viscous which depends on concentration and pH levels. The lowest gelation concentration of seed protein concentrate was found to be 14% and 8% when the proteins were dissolved in distilled water and 0.5 M or 1 M NaCl solution, respectively.
Single screw extrusion of cassava starch was evaluated as a pre-treatment for the enzymatic hydrolysis of the extrudate and fermentation to yield alcohol. The acid concentration, barrel temperature and moisture content showed that all the variables were significant. Increasing acid concentration or barrel temperature induced starch depolymerisation with a higher water solubility index and lower water absorption index. At 20 and 24% moisture contents the cold paste viscosity decreased. As a result of the addition of acid during extrusion cooking the degree of starch hydrolysis resulted in low hot paste viscosity. Acid concentration was significant in the production of reducing sugars. At concentrations above 0.024 N, as the temperature increased, the reducing sugar content also increased. Nevertheless, at concentrations below 0.024 N, the reducing sugar content showed the opposite result. The best yield of alcohol obtained from the extruded starch was 98.7% (0.56 g of ethanol/g starch), which, on average, was 5.7% and 6.8% higher than that obtained from starch extruded without acid and from starch gelatinized by the conventional method, respectively.
The production of
biomass enriched with copper ions were studied. For that reason the growth of
in whey with different concentrations of copper ions in batch process under semiaerobic and aerobic conditions were examined. The kinetics of copper ions accumulation in yeast cells, under the same conditions, as well as the reduction of chemical oxygen demand (COD) during yeast growth in aerobic condition, were monitored, as well. The concentration of copper ions in media up to 4 mg l
did not affect the yeast growth, whereas at a higher concentration, a marked decrease in the rate of yeast growth, ethanol production and lactose consumption occurred. In semiaerobic conditions, the maximum uptake of 0.35 mg Cu g
d.m. was obtained, while in aerobic conditions a lower uptake of 0.26 mg Cu g
d.m. and COD reduction of 85% were achieved. COD reduction was independent of the copper addition or uptake.
Antifungal effect of Micromeria myrtifolia Boiss. & Hohen. in Boiss. and Prangos uechtritzii Boiss. Hawsskn decoctions was tested against Alternaria alternata, Aspergillus niger, Aspergillus parasiticus, Botrytis cinerea, Fusarium oxysporum f.sp. melonis and Penicillium digitatum. Of the 2 substances tested Pr. uechtritzii, being present at 75 to 80% concentration in potato dextrose agar, partly inhibited growth of A. alternata, B. cinerea and P. digitatum. Pr. uechtritzii had higher antifungal effect than M. myrtifolia on mycelial growth during incubation. M. myrtifolia partly affected mycelial growth of A. alternata and A. niger at the beginning of incubation. But the mycelial growth of F. oxysporum was not inhibited by M. myrtifolia concentrations during incubation. Also, Pr. uechtritzii did not have any affect on mycelial growth of A. niger during incubation P. digitatum, the most sensitive microorganism to both decoctions. Higher decoction concentrations of plants used in study will be probably inhibit mycelial growth of microorganisms.
Authors:Ivana Marko, Štefan Stanko, and Réka Csicsaiová
This paper is about comparing the effectiveness of the sorbent materials of granulated activated carbon in removing of bromates from drinking water. The limit value (10 µgl−1) of bromates in the drinking water was stated by World Health Organization. In order to insure the reduced concentration of bromates in the drinking water, an experiment was performed using the batch test. In this experiment different types of sorbent materials with different properties were testing. Based on batch test were measured the parameters like the immediate adsorption capacity, the adsorption efficiency, and the concentration of bromates after the adsorption were measured at the evaluated time.
Authors:Youssef Regad, Bachir Elkihel, Farid Boushaba, and Mimoun Chourak
The main goal of this study is firstly to model the phenomenon of advection and diffusion of the gaseous residues of coal combustion. On the other hand, to study the dispersion of this pollution by varying the parameters like the wind and the resources of pollution, where there are four emissions: SO2, CO, NO2 and PM10. The present model will compare estimating concentrations with the results found by the contribution of the thermal power plant of Jerada city, where the American Environmental Regulatory Model is used. The results suggest that SO2, PM10, NO2 and CO concentration simulated by turbulent k-ε model in combination with the transport model of diluted species, at the 3h and 24h intervals, greater than their respective observed concentrations compared with the American Environmental Regulatory Model. The concentrations of the model found are very high and exceed the limit values under the study conditions. Indeed, the simulated model was used in 2D with a very low wind speed (10−4 m/s) and in the absence of gravity, hence the total neglect of altitude because the two sources of pollution are at the height of 120 m.