Changes In Organic Compounds Research Articles

Sensorial Attributes of Fermented Whey Drinks with Either Natural or Artificial Flavoring Agents

Abstract A clear-yellowish liquid, resulting from the separation and pressing of curds in the cheese-making process, is obtained, and it is commonly known as whey. Despite being commonly regarded as waste, whey still contains some nutrients such as protein, lactose, and minerals. These compounds endow whey with the potential to be processed into a food product. However, an unwanted sensory aspect can be caused by the presence of these organic compounds. This is a consequence of chemical changes in organic compounds within whey during production and storage, which can impact flavor and lead to the formation of off flavors. One alternative that can be employed to reduce off-flavors is the conversion of whey into probiotic drinks through a fermentation process involving lactic acid bacteria (LAB). Although a fermentation process could impart a more favorable sensory aspect to whey, it is still deemed necessary to incorporate natural or artificial flavorings. Orange (citrus) is a common flavor used in food products. Consequently, this study was conducted to enhance the sensory aspect of whey by fermenting it and adding natural and artificial citrus flavorings, with subsequent evaluation through consumer acceptance. According to the study results, significant findings were observed in flavored fermented whey, exhibiting higher consumer acceptance compared to fermented whey without flavor. In conclusion, the addition of both natural and artificial citrus flavorings to fermented whey served to enhance its sensory aspect and elevate consumer acceptance.

Vacuum ultraviolet irradiation for reduction of the toxicity of wastewater towards mammalian cells: Removal mechanism, changes in organic compounds, and toxicity alternatives

Vacuum ultraviolet (VUV, 185 + 254 nm) irradiation performs well for oxidation of model pollutants. However, oxidation of pollutants does not necessarily lead to a reduction in toxicity. Currently, a comprehensive understanding of the effect of VUV irradiation on the toxicity of real wastewater is still lacking. In this study, the influence of VUV irradiation on the toxicity of secondary effluents to Chinese hamster ovary (CHO) cells was investigated. The induction units of endogenous reactive oxygen species (ROS) and 8-hydroxyguanosine (8-OHdG) in cells continuously decreased with prolonged irradiation time. After 36 min of irradiation, the cytotoxicity and the genotoxicity of the secondary effluents were reduced by 57%–63% and 56%–61%, respectively. The UV (254 nm), •OH, and other substances generated during the VUV irradiation directly drive toxicity changes of wastewater. The contribution of •OH generated during VUV irradiation to the reductions in cytotoxicity and genotoxicity of the secondary effluents reached 72%–78% and 77%–84%, respectively. Hydroxyl radicals generated during VUV irradiation played an important role in the detoxification. The relative signal intensity of dissolved organic carbon (DOC) > 500 Da was partially removed, whereas that of DOC < 500 Da was small changed. Since the content of DOC > 500 Da in the samples was much lower than that of DOC < 500 Da, the removal of total DOC was only 15.8%-20.0% after 36 min of irradiation. The UV254 values and the fluorescence intensity values for different molecular weights (MWs) were all reduced effectively by VUV irradiation. Electron-rich organic compounds of all MWs were all sensitive to VUV irradiation. There were mono-linear relationships between changes in chemical indexes and changes in cytotoxicity or genotoxicity. The total fluorescence intensity (Ex: 220–420 nm, Em: 280–560 nm) was identified as the best indicator of the reduction in toxicity.

Alterations in aggregate characteristics of thermally heated water-repellent soil aggregates under laboratory conditions

Abstract The heat generated during wildfires modifies soil characteristics, including soil water repellency (SWR) and the water stability of aggregates, which are known to be interrelated. SWR lowers the rate of water entry into aggregates, minimizing aggregate disruption and subsequent erosion. This study aimed to examine these aggregate characteristics (SWR, water stability of aggregates) of thermally heated water-repellent soil aggregates under laboratory conditions. Water-repellent aggregates were collected from Eucalyptus grandis forest soil separately from four soil depths (0–5, 5–10, 10–15, and 15–20 cm) with varying initial repellency levels. Using an automated programmable muffle furnace, aggregates were separately exposed to three heating temperatures, T H (150, 200, 250 °C), three rates of heating (speed of rising temperature to reach relevant T H), R H (200, 400, 800 °C h−1), and three durations of exposure to relevant T H, E D (30, 60, 120 min). The molarity of an ethanol droplet test was used to measure the contact angle (contact angle&gt;90°). The water drop penetration time (WDPT) was also measured. The SWR of aggregates declined with the increasing T H and E D. All aggregates were wettable once exposed to 250 °C. At the lowest T H and E D (150 °C, 30 min), the contact angle was &lt;90° only in the least repellent aggregates collected from 10–15 and 15–20 cm depths. Although R H indicated the least influence on the measured parameters, the slowest R H (200 °C h−1) caused a comparatively greater decline in SWR. Water stability of aggregates increased with heating irrespective of decreasing SWR. Further investigations on heat-induced changes in organic compounds at molecular levels would be necessary to understand the theories for the behavior of aggregates.

Effectiveness of sodium sulfite as an electron acceptor for bioenhanced treatment of salt-containing water produced from ASP flooding

The wastewater produced from alkaline-surfactant-polymer (ASP) flooding is a complex multiphase mixture that contains oil, polymers, surfactants and other pollutants and is thus a salt-containing industrial waste recalcitrant to treatments. Through laboratory tests, this study assessed the effectiveness of using sodium sulfite as an electron acceptor for a modified anaerobic baffled reactor (ABR) for removing oil, suspended solids, polymers and surfactants from salt-containing wastewater produced from ASP flooding. During the 90-day operation, the method established in this study successively removed 52.8%, 98.6%, 77.0%, 21.2% and 21.5% of the chemical oxygen demand (COD), oil, suspended solids, polymers and surfactants, respectively, from the wastewater. The changes in organic compounds in the reactor during the treatment were monitored through gas chromatography-mass spectrometry (GC-MS), and the results showed that the established method was very effective in removing alkanes, alkenes, cycloalkanes, aromatic hydrocarbons and esters, and the organic macromolecules in the wastewater were degraded to small molecules. The main bacterial species and microbial communities in the reactor were characterized using molecular biological techniques, and the results indicated that under the stress of high pH and salts, Halomonas sp. gradually dominated and played a major role in degrading hydrocarbons. The findings of this study can aid the development of a cost-effective biological system to treat the water produced from ASP flooding.

Treatment of oil sands process water using petroleum coke: Field pilot

This is the first large-scale field pilot study that examined the feasibility and effectiveness of petroleum coke (PC), produced by a Fluid Coking Process, as an adsorbent for oil sands process water (OSPW) treatment. The pilot program consisted of an inline series of two reactors (pipeline reactor 1, and batch reactor 2) and lasted for approximately 4 months. The quality of treated OSPW as a function of residence time in the PC deposit under natural climatic conditions was assessed by looking at changes in organic compounds (acid extractable fraction (AEF), dissolved organic carbon (DOC), etc.), vanadium, and other trace element concentrations, major ions, conductivity, total suspended solids (TSS), pH and toxicity. The results indicated that the AEF adsorption by PC followed pseudo-second order kinetics and the overall combined removal efficiency of AEF was greater than 80%. Reactor 1 showed higher AEF removal than Reactor 2. DOC decreased about 50% after 4 weeks of retention in the PC deposit. An increase of vanadium concentration after PC contact indicated that vanadium leaching occurred. However, with increased residence time in the PC deposit, vanadium concentration decreased in the cells and tanks by 42% and 98%, respectively. Filtration through the PC deposit reduced the TSS in OSPW to less than laboratory detectable limits. Unlike untreated OSPW, treated OSPW did not show an acute toxic response based on whole effluent toxicity testing using trout, zooplankton, and bacteria. This study demonstrated that PC adsorption is a potentially commercially viable technology for highly efficient treatment of OSPW.

Changes in organic compounds secreted by roots in two Poaceae species (Hordeum vulgare and Polypogon monspenliensis) subjected to iron deficiency.

Despite their economic and ecological interests, Poaceae are affected by the low availability of iron in calcareous soils. Several studies focused on the capacity of this family to secrete phytosiderophores and organic acids as a mechanism of tolerance to iron deficiency. This work aimed at studying the physiological responses of two Poaceae species; Hordeum vulgare (cultivated barley) and Polypogon monspenliensis (spontaneous species) to iron deficiency, and evaluate especially the release of phytosiderophores and organic acids. For this purpose, seedlings of these two species were cultivated in complete nutrient solution with or without iron. The biomass production, iron status, phytosiderophores and organic acids release by roots were studied. The results demonstrated that Polypogon monspenliensis was relatively more tolerant to iron deficiency than Hordeum vulgare. Polypogon monspenliensis had the ability to secrete a higher amount of phytosiderophores and organic acids, especially citric, acetic, oxalic and malic acids, compared to Hordeum vulgare. We propose this spontaneous species as a forage plant in calcareous soils and in intercropping systems with fruit trees to prevent iron chlorosis.

Effect of recycle ratio on methanogenic anaerobic digestion of palm oil mill effluent (POME) in a stirred tank reactor assisted by ultrafiltration membrane into biogas in transition conditions

The purpose of this study is to increase the conversion of biogas production using digester type CSTR by recycling the effluent through ultrafiltration membrane at transition conditions (45°C). In this research was investigated the effect of recycle ratio on the pH profile, alkalinity, production, and biogas composition produced. Initially, the suitable loading up was determined by varying HRT at 25, 15, 10, and 6 days in 2 L CSTR with agitation rate 250 rpm, pH 7 ± 0.2, and at temperature of 45°C. Furthermore, the effect of the recycle ratio was determined by varying the recycle ratio, i.e. 0, 15, and 25%. Analysis of total solids (TS), volatile solids (VS), total suspended solids (TSS), volatile suspended solids (VSS), and chemical oxygen demand (COD) were carried out to study the changes of organic compounds that were converted into biogas. Gas analysis is also carried out by measuring the volume and composition of the biogas produced. The highest total biogas production was achieved at 25% recycle ratio of 33.15 x 10-2 L/g.VS.day, with the composition of methane (CH4), carbon dioxide (CO2), and hydrogen sulfide (H2S) were 79; 19; and 0.006% respectively.

The process research of anaerobic flora disintegrating excess sludge

Large amounts of sewage sludge are produced from activated sludge processes, causing serious secondary pollution. Thus, the development of stable, safe, and low-cost methods to dispose excess sludge has gradually become a popular research topic. The anaerobic/anaerobic microorganism method shows good prospects for industrialization because of its advantages such as low cost and no secondary pollution. The current study focuses on the effect of anaerobic microorganisms on waste activated sludge during anaerobic fermentation. In this research, the changes of organic compounds, extracellular enzymes, and size distributions in the process of anaerobic flora disintegrating excess sludge were measured to clarify the disintegrating process. In various disintegrating products, COD was observed to be suitable for characterizing the degree of sludge disintegration. The disintegration efficiency of anaerobic flora was 34.86% or 3.5 times higher than that of the anaerobic environment. Lipase played an important role in breaking cell walls. There was a dynamic equilibrium in the sludge disintegration and reuse of disintegration products. The change in size distribution showed that easily degraded materials accumulated and large granular sludge was destroyed. The present study lays the foundation for future studies on the optimization of conditions for sludge disintegration.

Electrochemical Oxidation of Safrole Using Ti/Ru X Ti(1 − X)O2 System: Preparation, Characterization, and Role of Electrode Composition

Oxidation processes introduce structural changes in organic substrates. Electrooxidation is an alternative synthetic route that can help scientists conduct desired changes in organic compounds. In this study, we investigated the Ti/Ru X Ti(1 − X)O2 system and used safrole (SF) as model substrate, to understand the role played by electrode composition in organic substances oxidation. We characterized the surface of the prepared electrodes and conducted controlled potential electrolysis with potential pulse, which oxidized 98 % SF. Electrode efficiency depended on the electrode composition—higher RuO2 concentration led to a more efficient process. Our results showed that all the electrodes generated the same intermediates regardless of the composition, indicating that the same reaction mechanism occurred in all cases, as corroborated by mechanistic parameters. Electrolysis under controlled current generated the same intermediates as electrolysis under controlled potential. The main difference between these two types of electrolyses was that controlled current promoted at least five times faster reaction, which resulted in substrate mineralization, an outcome that is not interesting for the synthetic process.

Ionizing Radiation: Friend or Foe of the Origins of Life?

Ionizing Radiation: Friend or Foe of the Origins of Life?

Changes in the organic compounds following sun drying of edible black ant (Polyrhachis vicinaRoger)

Edible black ant ( Polyrhachis vicina Roger) is a traditional edible insect species in China. It has long been used as an important ingredient of health foods. The aim of the present study was to investigate the changes of organic compounds following sun drying of edible black ant. The results showed that fresh and sun dried edible black ant samples have 28 organic components. Nine of them found in the present study have not been reported previously such as 8-heptadecene and (E,E)-6,10,14-trimethyl-5,9,13-pentadecatrien-2-one. Five constituents disappeared and 4 components formed while the ant was sun dried. The major organic compounds of fresh and sun dried edible black ant belong to fatty acids and hydrocarbons. Some compounds such as fatty acids, aldehyde and alkanes appeared during the procedure indicating that sun drying speeds up lipid oxidation and hydrolytic rancidity.

Changes in organic compounds during leaf litter leaching: laboratory experiment on eight plant species of the Sudano-guinea Savannas of Ngaoundere, Cameroon

A laboratory experiment was carried out on the leaf litter of 8 agroforestry plant species of the Sudano-guinea Savannas of Ngaoundere in order to compare patterns of their water absorption and dynamics of four important energetic organic compounds (soluble sugars, cellulose, phenol and lignin) among these plant species during the leaching phase and to determine the influence of initial litter properties on these processes. To this end, 168 samples of leaf litter (5.00 ± 0.01 g) of Annona senegalensis, Lophira lanceolata, Syzygium guineense var. guineense, Syzygium guineense var. macrocarpum, Vitellaria paradoxa, Vitex doniana, Vitex madiensis and Ximenia americana were immersed for 15 days in distilled water at a temperature of 23 °C and relative humidity of 65 ± 1%. Three samples of each plant species were taken at 1, 6, 24, 72, 168, 240 and 360 hours. Depending on the species, water absorption capacity after 360 h of leaching varied from 162.77 (S. g. var. macrocarpum) to 264.00% (V. madiensis) of dry litter mass. The release of water-soluble substances varied between 9.61 (L. lanceolata) and 34.12% (X. americana). Water absorption and release of water-soluble substances rate constants were the highest in V. madiensis (0.32 h-1 and 0.25 h-1) and the lowest one respectively in S. g. guineense (0.03 h-1) and S. g. var. macrocarpum (0.006 h-1). Organic compound of original litter also varied significantly among species and decreased with leaching time for water-soluble sugars and phenols, while increased for cellulose and lignin. Water absorption by litter was significantly correlated with initial water-soluble sugars and phenol content, leaf litter area and thickness. The release of water-soluble substances by litters was also correlated with initial water-soluble sugars, water content and leaf litter area. The leaching rate constant was correlated with that of water absorption. These preliminary results lead to a better understanding of the litter decomposition processes of agroforestry plant species of Ngaoundere and thus help in making the most appropriate choice of indigenous plant species for domestication that could help to improve soil fertility and eventually to protect the biodiversity.

Recent Advances in the Study of Mechanochromic Transitions of Organic Compounds

The article reviews a wide variety of mechanically induced colour changes in organic compounds. It considers structural and chemical transformations of the compounds that cause mechanochromism. When relevant, technical applications of the phenomenon are also highlighted.

Integrated assessment for anaerobic biodegradability of organic compounds using the analytical hierarchy process

Anaerobic biodegradability of organic compounds can be assessed from the changes in organic compounds, the end products, and the activity of microorganisms. In this study, all three of these variables were considered to integrate assessment of the anaerobic biodegradability of organic compounds. The analytical hierarchy process (AHP) was introduced to integrate the assessment. Real values between 0 and 10 were determined in the pairwise comparison matrix according to the values of assessment indices of the three variables. A new adjustment method, which can obtain minimum adjustment of the values in matrix, was proposed to reach the acceptable consistency of the matrix. Finally, the anaerobic biodegradability of 14 organic compounds was assessed using AHP.

Seasonal changes in organic compounds in soil solutions obtained from volcanic ash soils under different land uses

We investigated the organic matter composition in soil solutions as influenced by land use. Undisturbed mineral soils were collected periodically from mineral layers of Andosols under coniferous and deciduous forest, grasslands and upland fields for 1 year using soil core samplers. Soil solutions were obtained by centrifugation under −1.55×10 6 Pa condition, which equals to 4.2 pF. The dissolved organic carbon (DOC), hexoses, pentoses, phenolic acids and amino acids in soil solutions were determined. The concentrations of DOC under forest and grassland stands were not influenced by precipitation, but were negatively correlated to the yield of soil solution ( P<0.01). Temporal variations in concentrations of hexoses were similar to those of DOC at all Fujisawa sites but not at the Tsukui sites. Except for one forest stand, the concentrations of hexoses increased from autumn to winter. Concentrations of pentoses and phenolic acids showed similar seasonal variation in the forests and grasslands, and peaked in autumn and spring. Variations in the concentrations of pentoses corresponded to litter fall and ground grass cutting in forests, drying of grass at grasslands and harvest at upland fields. Although the concentrations of phenolic acids varied with seasons, differences between land uses were not clear. The release of phenolic acids might depend on the variation of the temperature. Correlations between pentoses and phenolic acids and DOC were weak. The concentrations of amino acids were lower than those of other organic compounds at all sites. At the upland fields, the concentrations of amino acids were significantly ( P<0.01) correlated with those of hexoses. The composition of dissolved organic matter (DOM) varied throughout the year. Seasonal changes in organic matters in soil solutions depended on yields of soil solution, temperature variations and the timing of litter supply under different land use.

Organic pollutants in precipitation: determination of pesticides and polycyclic aromatic hydrocarbons in Gdańsk, Poland

The paper presents the results of determination of selected organic pollutants in atmospheric precipitation. Samples of atmospheric precipitation in the form of rain water and snow were collected in five places in the area of Gdańsk, which enabled some conclusions to be drawn on the influence of sampling position on the content of samples. Two different groups of compounds were determined: polycyclic aromatic hydrocarbons (PAHs) and pesticides. All applied analytical methods were previously checked out and used for other types of water samples (e.g. river waters, sea waters, drinking water). Capillary gas chromatography with specific detectors was used for final determination. Samples were collected during two separate periods of six months each, which permits us to find out some qualitative and quantitative changes of organic compounds in an urban area in different seasons. The most often detected pesticides were: terbuthylazine and chlorfenwinfos, whereas bromophos and atrazine occurred rarely. If detected, the concentration of pesticides ranged from 1 to 920 ng dm −3. The total concentration of the measured polycyclic aromatic hydrocarbons varied between 1 ng dm −3 and 12.8 μg dm −3. Among all PAHs phenanthrene, fluoranthene and pyrene were the most often determined compounds.

Studies on litter decomposition processes in a temperate forest ecosystem. I. Change of organic matter in oak (Quercus liaotungensisKoidz.) twigs

The litter bag method was used in this study on the decomposition of twigs of an oak (Quercus liaotungensisKoidz.) which is dominant in the warm temperate deciduous forests. This continual 5‐year investigation was to measure the changes of organic compounds in twig litter. The decomposition of oak twigs based on rates of the mass loss during the first 5 years was simulated using the Olson exponential equation. The simulated data fitted well with the observed values. Oak twigs were predicted to reach 95% mass loss within 21 years. During the first 5 years, the concentration of protein in the remaining litter increased from 3.5% to 5.5%, while the concentration of hemicellulose decreased from 16.0% to 8.0%. However, there was no obvious change in the concentrations of lignin and cellulose. The losses of lignin, crude‐cellulose and hemicellulose could be well simulated using the Olson exponential equation. However, this was not true for cellulose and protein.

Chemical Changes of Organic Compounds in Chlorinated Water. XIX. Production of Alkylpolychlorinated Phenoxyphenols (Predioxins) by Aqueous Chlorination of Alkylphenols.

Aqueous alkylphenol solutions were treated with chlorine at 20°C under various experimental conditions. Changes in the compositions of the chlorination products in water were determined by gas chromatographic (GC) and GC-mass spectrometric (GC-MS) analyses of diethyl ether extracts. Alkylphenols were shown to produce a variety of chlorinated compounds, including alkylpolychlorinated phenoxyphenols (predioxins), having one to five chlorine atoms, as by-products in chlorine-treated water. Production of some of these predioxins is dependent on the number of equivalents of chlorine per mol of compound and on the reaction pH. These results suggest that chlorine treatment of water contaminated with alkylphenols leads to the production of predioxins, which are precursors of the highly toxic chlorinated dibenzo-p-dioxins.

Chemical Changes of Organic Compounds in Chlorinated Water. XVIII. Kinetics and Mechanisms for Chlorohydrin Formation during Reactions of Aqueous Chlorine with Lipid Components.

A series of fatty acids and their triglycerides were subjected to chlorination under similar conditions to those for water chlorination. Unsaturated fatty acids were more reactive towards chlorine than their corresponding ester derivatives, as shown by the reaction rate and the extent of chlorine incorporation. However, saturated fatty acids did not react with chlorine. A number of chlorinated and oxygenated products of these reactions were tentatively identified using electron impact and chemical ionization mass spectrometry. Chlorohydrin, as a major product, resulting from the reaction of oleic acid with chlorine was stable in water. However, chlorohydrins and dichlorohydrins formed by the reactions of linoleic or linolenic acid with chlorine further reacted with chlorine to give organic chlorinated compounds which were stable in water.

Studies on decomposition ofCeratophyllum demersum litter under laboratory and field conditions: losses of dry mass and nutrients, qualitative changes in organic compounds and consequences for ambient water and sediments

A study was made of decomposition ofCeratophyllum demersum litter over a 17-day period under controlled conditions of temperature and oxygen (5, 10 and 18 °C; aerobic and anaerobic) and over a 169-day period in the field (Lake Vechten, The Netherlands). Litter, water and sediment were sampled on the 0, 2, 4, 7 and 17th day under controlled conditions and on the 0, 17, 49, 127 and 169th day in the field. The litter was analyzed quantitatively for dry mass, ash, carbon, nitrogen, phosphorus and qualitatively of organic composition by pyrolysis mass spectrometry. The water was analyzed for the elemental concentrations of organic carbon (total and dissolved), nitrogen (total, ammonia and particulate) and phosphorus (total and orthophosphate) and for the concentrations of photosynthetic pigments and bacteria. The sediment was analyzed for the elemental concentrations of nitrogen, carbon and phosphorus, and for bacterial numbers.