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关键词： Spark plasma   Peppermint distillate   Decontamination   Essential oil  

摘要： Microbial contamination of herbal distillates is one of the crucial problems that the market is commonly facing. Spark plasma can be proposed as a potential emerging solution for the decontamination of liquids even with the sensitive aromatic compound like peppermint (Mentha piperita L.) distillate. However, its probable effects on the physicochemical properties of distillate is the main area of concern which will be discussed in the current paper. According to our results, spark plasma with an energy of 2 J/pulse is able to achieve a 4-log reduction in Pseudomonas aeruginosa counts after 4 min of treatment. Various assessments including pH analysis, color measurement, evaluation of essential oil content and composition are employed to determine the likely side effects of the method on the final product. The results show that the plasma processing does not make any sensible changes in the peppermint distillate acidity and color. According to the results, the peppermint essential oil content decreases only about 4% in the samples affected by the plasma, however, content of menthol as the main compound of peppermint distillate reduces about 17%.

关键词： Ozone treatment   Textural properties   Induction time   Melting behaviour   Fat particle size  

摘要： The goal of this research was to investigate the effects of the ozone treatment (OT) to raw cream on the physicochemical, microbiological, thermal, and oxidative properties of butter. For this purpose, butter samples were produced from raw cream, which was ozone-treated for 5 (OT-5), 15 (OT-15), 30 (OT-30), and 60 (OT-60) min. The control sample was also produced from non-ozonated raw cream. OT increased firmness, consistency, and fat particle size values of cream. The firmness of butter was between 97 and 380 N. Average fat particle size of samples (D[3.2]) ranged from 22.1 to 30.2 mu m, in which OT decreased it. A monomodal fat particle size distribution was determined in all-butter samples. OT decreased b value (yellowness) of butter, and the lowest value was determined in OT-60. The induction time of butter changed from 1.04 (OT-60) - 32.9 h (control). Two melting peaks were determined in butter samples at 14.2-14.6 and 32.3-33 degrees C. Ozonation for 60 min caused 2.01 log reduction in Staphylococci. Above 15 min, OT completely inactivated Salmonella and yeast-mould. Coliform was not detected in OT-30 and OT-60. The results showed that OT resulted in higher microbiological quality in butter from raw cream.

关键词： Sage herbal dust   Microwave-assisted   hydrodistillation   Terpenoids   Kinetics   Thermal behavior  

摘要： Sage herbal dust generated as a by-product from filter-tea factory contains various bioactive compounds which secured its economic potential towards valorization of under-utilized stream. The aim of this work was to utilize sage herbal dust as raw material for the recovery of value-added product. Comparative evaluation of hydrodistillation (HD) and microwave-assisted hydrodistillation (MWHD) processes applied for isolation of sage herbal dust essential oil (EO) were applied for this purpose and EO yield varied from 0.50 to 1.90%. Distillation experiments performed at different levels of power and kinetics of EO recovery were monitored, while four empirical kinetic equations were successfully applied for modeling of process kinetics according to appropriate values of statistical parameters (R2 and AARD). GC-MS analysis was applied for chemical characterization of sage EOs, while DPPH assay was used to determine in vitro bioactivity and results suggested that power affected terpenoid profile and antioxidant activity in case of HD and MWHD. Thermal analysis of obtained EOs was utilized to establish correlation between thermal behavior and terpenoids profile. Results suggested that MWHD could provide excellent alternative for production of high-quality sage EO with high content of oxygenated terpenoids and adequate bioactivity. (C) 2020 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.

关键词： Physicochemical properties  

摘要： The use of cassava starch as potential substitute for corn starch in the production of salad cream (SC) may contribute to sustainable utilization of cassava roots. This study investigated the physicochemical properties, rheology, and storage stability of SC made with starches from eight cassava varieties. SC produced was stored in an airtight plastic jar for 3 months at ambient temperature (25 +/- 2 degrees C). Changes in the physicochemical properties, rheology, and storage stability of the stored SC samples were determined using standard methods. There was a significant decrease (p < .05) in the solid contents of the SC while the peroxide increased with storage period. There was a significant increase (p < .05) in the total plate count (TPC) of the SC samples with storage period. This study further showed that the SC samples were all chemically and microbially stable considering the standards for peroxide value (PV) (<10 meg/kg) and TPC (<10(4) cfu/g) within the 3 months storage. Practical applications The salad cream (SC) consumed in Nigeria is mainly imported and expensive. Local brands of the product are scarce in the grocery. SC is produced majorly from modified corn flour or starch with other ingredients. To make local manufacture of SC economically feasible, it is practically imperative to find a locally available replacement for corn starch. This study was then conceived to screen starches from some elite cassava varieties for use in SC production. It has been established from this study that the cassava starches tested could be a suitable substitute for corn starch for the production of SC. However, the most stable SC from textural point of view was derived from a yellow fleshed cassava variety (TMS 1206), which is very important for the consumer preference. With appropriate addition of other ingredients in the production, consumers are assured of best quality SC.

关键词： combined fire extinguishing agent   microemulsion   water   surfactant   halohydrocarbon   electrical conductivity   heat capacity   dynamic light scattering   microdroplet size   fire extinguishing efficiency  

摘要： The research findings related to synthesis and study of water-sodium dodecyl sulfate-1-pentanol-triethanolamine-2-iodoheptafluoropropane and water-sodium dodecyl sulfate-1-pentanol-triethanolamine-1,2-dibromotetrafluoroethane microemulsions at the standard temperature were summarized. Use of microemulsions provides a promising means of combining with water chemically active inhibitors such as halohydrocarbons, which are water-immiscible under ambient conditions. This affords fire extinguishing agents integrating different flame suppression mechanisms: chemical inhibition of the combustion reaction and flame cooling. The electrical conductivities and heat capacities of the microemulsions synthesized were determined and used for analyzing the structural changes caused in them by changes in their composition. Using the dynamic light scattering method, the size of the microdroplets of the microemulsions was determined, and their size distribution was examined. Based on the data obtained, the fire extinguishing performance of the microemulsions (cooling capacity, possible applications, and mechanism of action) was described. Laboratory tests of the fire extinguishing efficiency of the microemulsions were carried out.

摘要： Balanced fertilization with N, P, and K fertilizers (NPK) is usually recommended to increase crop yield, while little is known on whether the effectiveness differs in soils with different fertilization histories. A greenhouse experiment grown with winter wheat (Triticum aestivum L.) and fertilized with NPK was conducted using soils that had been under five fertilization histories, including NPK, unbalanced fertilizers without one of the major elements (NP, PK, and NK), and an unfertilized treatment (Nil), for 18 yr. Wheat biomass and nutrient uptake from the PK treatment was 23-114% higher, from the NP was similar (except for N uptake), and from the NK and Nil was 14-58% lower, relative to the NPK treatment. Network analysis revealed positive associations of wheat biomass with available P (AvaP) and some specific taxa (i.e., Flavisolibacter and Pontibacter enriched in PK treatment and Microbacterium and Nocardioides depleted in NK and Nil treatments), besides positive associations between AvaP and Microbacterium and Nocardioides abundances. Genus Baccillus enriched in PK treatment was identified as the keystone taxa. These results suggest that significantly induced crop yield in PK treatment by a single season application of balanced fertilizers may be associated with higher AvaP and stimulation of microorganisms involved in nutrient cycling and crop growth promotion, while lower yield observed in NK treatment may be related to lower AvaP and suppression of microorganisms involved in soil P availability. Our findings implied that besides balanced fertilization, more strategies are required for quickly improving crop yield according to soil nature.

关键词： Dentinogenesis imperfecta   DSPP   EDS   Microhardness   Mutation   MicroCT  

摘要： Aim: To investigate the chemical and mechanical properties of teeth affected by a 1-bp deletion (c.2688delT) in the DSPP gene. Methods and Materials: Maxillary first premolars were extracted from the affected individual at age 9 years due to the orthodontic reason for crowding. A sample was imbedded in epoxy resin and sectioned buccolingually, after micro-computerized tomography (mu CT) images were taken. Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometry (EDS) and Vickers microhardness testing were also performed. Results: mu CT reconstruction and analysis showed an irregularly obliterated pulp chamber and an extremely small pulpal volume in the DGI-II sample. The mineral density and microhardness scores were smaller in the dentin of the DGI-II sample compared to the wild-type. Mg content was lower in the dentin of the DGI-II sample compared to the wild-type. Conclusion: This study shows that dentin affected by a 1-bp deletion in DSPP has a reduced mineral density, diminished microhardness and reduced Mg content.

关键词： Liquid egg white   Phospholipase A(2)   Meringue   Creep-recovery rheology   Storage stability   Sensorial and textural characterization  

摘要： This research aimed to investigate the effects of various concentrations (0.1;0.2 and 0.3 v/v %) of phospholipase A(2)(PLA) enzyme-modified liquid egg albumen (LEA) on color, water activity, specific volume, textural profile analysis, and sensorial characteristics of cooked meringues for 90 days storage period at room temperature. Also, the rheological creep-recovery changes, specific density, color, and physico-functional properties of meringue batters were evaluated. The meringue batter density in the control group (0.47 +/- 0.01) decreased significantly (p < 0.05) after PLA hydrolysis, while better specific gravity values were obtained in 0.3% enzyme concentration (0.36 +/- 0.01). The use of the enzyme-hydrolyzed LEA also significantly (p < 0.05) decreased water activity with control, 0.1, 0.2 and 0.3% of PLA (0.447 +/- 0.01;0.429 +/- 0.01;0.429 +/- 0.01, and 0.420 +/- 0.01), respectively. The batter densities of meringues prepared by PLA enzyme decreased with increasing the enzyme concentration, while as enzyme concentration increased, the meringues lost its elasticity. The increase in enzyme concentration leads to a significant increase in meringue's specific volume values. Sensory analysis of meringues showed that the lowest scores obtained by the control group, and the enzyme hydrolyzed with 0.2% were acceptable. The PLA modification provided the storage stability of meringues in hardness values. This study highlights the use of the PLA enzyme-modified LEA in meringue production results in the development of functional properties and storage stability.

关键词： pit lakes   Muskau Arch   water chemistry   temporal changes  

摘要： Thirteen pit lakes of the Muskau Arch (Western Poland) were studied in the summer season of 2016. The lakes display great geomorphological and hydrochemical diversity. The aim of the study was to characterize temporal changes in the physicochemical conditions of the pit lakes over the last 30 years (1986-2016) and to determine the main factors influencing their evolution. All the lakes were characterized in terms of the same set of physicochemical parameters measured and used for comparative analysis with literature data from the years 1986 and 1992. The results showed significant temporal differentiation in terms of morphometric features and most of the physicochemical characteristics. pH, EC, Ca2+, Mg2+ and total Fe were among the most significantly differentiating parameters. A similar pattern of changes was found for most of the lakes, suggesting natural fluctuations. Despite the differences in values of thermal and oxygen profiles, there were also similarities in lake stratification. Additionally, meromictic conditions were found in 4 lakes. In some of the lakes a negative effect of neutralization and fertilization of the water was observed. Our results showed that the Muskau Arch lakes are subject to dynamic hydrogeological and hydrochemical changes. In addition to natural changes, human-caused transformations were among the key factors responsible for the differentiation of the physicochemical conditions.

关键词： biosignature   digitate sinter   hot springs   microbial communities   silicification   stromatolite  

摘要： Digitate siliceous hot spring deposits are a form of biomediated sinter that is relatively common in the Taupo Volcanic Zone (TVZ), New Zealand, and elsewhere on Earth. Such deposits have gained prominence recently because of their morphological similarity to opaline silica rocks of likely hot spring origin found by the Spirit rover on Mars and the consequent implications for potential biosignatures there. Here, we investigate the possible relationship between microbial community composition and morphological diversity among digitate structures from actively forming siliceous hot spring sinters depositing subaerially in shallow discharge channels and around pool rims at several physicochemically distinct geothermal fields in the TVZ. The TVZ digitate sinters range in morphologic subtype from knobby to spicular, and are shown to be microstromatolites that grow under varied pH ranges, temperatures, and water chemistries. Scanning electron microscopy and molecular analyses revealed that TVZ digitate sinters are intimately associated with a diverse array of bacterial, archaeal and eukaryotic micro-organisms, and for most digitate structures the diversity and quantity of prokaryotes was higher than that of eukaryotes. However, microbial community composition was not correlated with morphologic subtypes of digitate sinter, and observations provided limited evidence that pH (acidic versus alkali) affects morphology. Instead, results suggest hydrodynamics may be an important factor influencing variations in morphology, while water chemistry, pH, and temperature are strong drivers of microbial composition and diversity.