Dry Transfer Inoculation of Low-Moisture Spices Containing Antimicrobial Compounds

2017 ◽  
Vol 80 (2) ◽  
pp. 338-344 ◽  
Author(s):  
Ian M. Hildebrandt ◽  
Chuxuan Hu ◽  
Elizabeth M. Grasso-Kelley ◽  
Peiran Ye ◽  
Nathan M. Anderson ◽  
...  
Keyword(s):  
Aqueous Suspension ◽  
Aqueous Media ◽  
Food Product ◽  
Black Pepper ◽  
Antimicrobial Compounds ◽  
High Concentration ◽  
Silica Beads ◽  
Ginger Powder ◽  
Inoculation Procedure ◽  
Transfer Method

ABSTRACT Inoculation of a food product for use in subsequent validation studies typically makes use of a high concentration cocktail of microorganisms suspended in aqueous media. However, this inoculation method may prove difficult particularly when the food product is a low-moisture food containing antimicrobial compounds, such as some dried spices. In this study, a dry transfer method for inoculation of clove powder, oregano leaves, ginger powder, and ground black pepper with a five-serovar cocktail of Salmonella was developed and compared with a traditional aqueous inoculation procedure. Spices were inoculated at three levels, 10, 8, and 6 log CFU/g, by using both an aqueous suspension of Salmonella and a dry transfer of Salmonella from previously inoculated silica beads. At the highest inoculation level, the dry transfer method resulted in a significantly higher microbial load (P < 0.05) for ground cloves and oregano, but not for ginger and ground black pepper. At the intermediate inoculation level, differences were apparent only for ginger and black pepper. Inoculation levels of 6 log CFU/g resulted in recoveries below detection limits for both methods of inoculation. Additional examination on the survival of Salmonella on silica beads after inoculation and in clove powder after dry transfer from silica beads showed linear rates of decline, with a rate of −0.011 log CFU/g/day for beads and −0.015 log CFU/g/day for clove powder. The results suggest that dry transfer of Salmonella via inoculated silica beads is a viable alternative when traditional aqueous inoculation is not feasible.

scholarly journals Red-Emitting Hybrid Based on Eu3+-dbm Complex Anchored on Silica Nanoparticles Surface by Carboxylic Acid for Biomarker Application

Materials ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 5494
Author(s):  
João A. O. Santos ◽  
Alessandra M. G. Mutti ◽  
Airton G. Bispo-Jr ◽  
Ana M. Pires ◽  
Sergio A. M. Lima
Keyword(s):  
Carboxylic Acid ◽  
Aqueous Suspension ◽  
Aqueous Media ◽  
Particle Morphology ◽  
Hybrid Structure ◽  
Hierarchical Organization ◽  
Stable Suspension ◽  
Carboxylate Groups ◽  
Red Luminescence ◽  
Average Size

Luminescent organic-inorganic hybrids containing lanthanides (Ln3+) have been prominent for applications such as luminescent bio-probes in biological assays. In this sense, a luminescent hybrid based on dense silica (SiO2) nanospheres decorated with Eu3+ β–diketonate complexes using dibenzoylmethane (Hdbm) as a luminescent antenna was developed by using a hierarchical organization in four steps: (i) anchoring of 3-aminopropyltriethoxysilane (APTES) organosilane on the SiO2 surface, (ii) formation of a carboxylic acid ligand, (iii) coordination of Eu3+ to the carboxylate groups and (iv) coordination of dbm− to Eu3+. The hybrid structure was elucidated through the correlation of thermogravimetry, silicon nuclear magnetic resonance and photoluminescence. Results indicate that the carboxylic acid-Eu3+-dbm hybrid was formed on the surface of the particles with no detectable changes on their size or shape after all the four steps (average size of 32 ± 7 nm). A surface charge of −27.8 mV was achieved for the hybrid, assuring a stable suspension in aqueous media. The Eu3+ complex provides intense red luminescence, characteristic of Eu3+5D0→7FJ electronic transitions, with an intrinsic emission quantum yield of 38%, even in an aqueous suspension. Therefore, the correlation of luminescence, structure, particle morphology and fluorescence microscopy images make the hybrid promising for application in bioimaging.

Dynamics of water, hydrated-ions and charged polymers in highly-confined films, and their role in friction modification

2003 ◽  
Vol 790 ◽  
Author(s):  
Jacob Klein ◽  
Uri Raviv ◽  
Susan Perkin ◽  
Nir Kampf ◽  
Suzanne Giasson
Keyword(s):  
Polymer Brushes ◽  
Aqueous Media ◽  
Free Water ◽  
Aqueous Salt Solution ◽  
Ball Bearings ◽  
High Concentration ◽  
Charged Surfaces ◽  
Hydrated Ions ◽  
Charged Polymer ◽  
The One

ABSTRACTRecent studies have revealed that, in contrast to non-associating liquids such as oils or organic solvents, salt-free water retains a viscosity close to its bulk value even when confined to films thinner than some 3 nm, indeed down to only one or two monolayers thick [1,2]. For the case of high concentration aqueous salt solution compressed down to subnanometer films between charged surfaces, the trapped hydrated ions serve to act as molecular ball-bearings, sustaining a large load while remaining very fluid under shear [3]. This behaviour is attributed to the tenacity of the hydration sheaths together with their rapid relaxation time. Finally, a very recent study [4] has shown that when charged polymer brushes in aqueous media are compressed and slid past each other, they provide a lubrication that is considerably superior to that afforded by neutral brushes: This is attributed on the one hand to the resistance to mutual interpenetration of the chains due to entropic barriers in the good-solvent conditions, and, on the other hand, to the hydration-sheaths on the charged polymer segments which can act – as noted above – as molecular ball-bearings.

Diameter-Selective Solubilization of Carbon Nanotubes by Lipid Micelles

2008 ◽  
Vol 8 (1) ◽  
pp. 420-423 ◽  
Author(s):  
Dimitrios Tasis ◽  
Konstantinos Papagelis ◽  
Dionysios Douroumis ◽  
James R. Smith ◽  
Nikolaos Bouropoulos ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanostructures ◽  
Aqueous Suspension ◽  
Aqueous Media ◽  
Microscopy Imaging ◽  
Force Microscopy ◽  
Atomic Force ◽  
One Step ◽  
The One ◽  
Walled Carbon Nanotubes

The one-step dispersion of HiPco single-walled carbon nanotubes in aqueous media with the use of a synthetic lyso-phosphatidylcholine was studied. Solubilization occurs through wrapping of lipid molecules around the circumference of the tubes, yielding lipid monolayers on the graphitic sidewalls as evidenced by atomic force microscopy imaging and dynamic light scattering measurements. Raman spectroscopy showed that the dispersion and centrifugation process leads to an effective enrichment of the stable aqueous suspension in carbon nanostructures with smaller diameters.

The Corrosion Attack on Stainless Steel 316L and WC-Co in High Sulphate-Chloride Ratio

2015 ◽  
Vol 1087 ◽  
pp. 410-414
Author(s):  
Azzura Ismail
Keyword(s):  
Aqueous Media ◽  
Austenitic Stainless Steels ◽  
Localized Corrosion ◽  
Corrosion Mechanism ◽  
High Concentration ◽  
Stainless Steel 316L ◽  
Corrosion Attack ◽  
Corrosive Media ◽  
Pitting Potential ◽  
Sulphate Chloride

Austenitic stainless steels and cermets alloy has been used extensively in many sectors due to their highly resistance to corrosion attack and excel in mechanical properties. However, in corrosive media both materials are susceptible to corrosion attack especially in seawater and high temperature. Cermet alloys are a combination of ceramic and metal. Therefore, cermets exist in high corrosion resistance in aqueous media and the corrosion rate is complex to identify. This paper presents the corrosion mechanism of 316L and cermets alloy exposed to high concentration of sulphate in the salinity of seawater. The solution (media) was prepared according to the same composition as seawater including pH, salinity and dissolved oxygen. The corrosion mechanism were characterized to breakdown potential (Eb)of 316L which are the potential once reaches a sufficiently positive value and also known as pitting potential. This is the most point where localized corrosion susceptibility to evaluate and considered a potential, which could be an appropriate point according to any given combination of material/ambient/testing methods. TheEbvalue of 316L in high sulphate are higher compared to seawater in every temperature which elucidate that some anions accelerate corrosion attack whereas some anions such as sulphate behaves as inhibiting effect to 316L.

scholarly journals Effects of dissolved metal chlorides on the behavior of silica nanoparticles in aqueous media

2014 ◽  
Vol 12 (4) ◽  
pp. 480-491 ◽  
Author(s):  
Vladimir Gun’ko ◽  
Lyudmyla Andriyko ◽  
Vladimir Zarko ◽  
Andrij Marynin ◽  
Valentyn Olishevskyi ◽  
...  
Keyword(s):  
Zeta Potential ◽  
Aqueous Media ◽  
Salt Content ◽  
Silica Content ◽  
Correlation Spectroscopy ◽  
High Concentration ◽  
Screening Length ◽  
Photon Correlation ◽  
Metal Chlorides ◽  
Primary Particles

AbstractEffects of chlorides of univalent (LiCl, NaCl, KCl), bivalent (MgCl2, BaCl2) and trivalent (AlCl3) metals at different concentration (0.001–0.1 M) on the behavior of nanosilica A-200 (0.5–5 wt.%) in aqueous media are analyzed using photon correlation spectroscopy (particle size distribution, PSD), electrophoresis (zeta potential ζ), potentiometric titration (surface charge density), and estimation of screening length of primary particles and their aggregates. The zeta potential and the PSD are affected by silica content, pH, and concentration and type of dissolved salts. Smaller but more strongly hydrated Li+ cations caused stronger nonlinear dependences of the zeta potential on pH and salt content than Na+ or K+. This nonlinearity is much stronger at a lower content of silica (0.5–1 wt.%) than at C A-200 = 2.5 or 5 wt.%. At a high concentration of nanosilica (5 wt.%) the effect of K+ ions causes stronger diminution of the negative value of the zeta potential due to better adsorption of larger cations. Therefore, the influence of K+ on increasing screening length is stronger than that of Na+ for both primary nanoparticles and their aggregates. A similar difference in the ζ values is observed for different in size cations Ba2+ and Mg2+.

Corrosion Behavior of WC-Co in High Sulphate Content

2014 ◽  
Vol 911 ◽  
pp. 82-86 ◽  
Author(s):  
A. Ismail
Keyword(s):  
Corrosion Rate ◽  
Aqueous Media ◽  
Corrosion Mechanism ◽  
High Concentration ◽  
Corrosion Attack ◽  
High Corrosion Resistance ◽  
Sulphate Content ◽  
Ceramic Composition ◽  
Inhibiting Effect ◽  
C 50

Cermet alloys are a combination of ceramic and metal. Therefore, cermets exist in high corrosion resistance in aqueous media. However, because of the nature of cermet alloys, which have a metal and ceramic composition, the corrosion rate is complex to identify. The corrosion attack could be assessed by calculating the corrosion rate or through electrochemistry evaluation. Generally, the corrosiveness of media increased as the anions contents increased. This paper presents the corrosion mechanism of cobalt tungsten-carbide (WC-Co) exposed to a high concentration of sulphate in the salinity of seawater. The solution (media) was prepared according to the same composition as seawater including pH, salinity and dissolved oxygen. The corrosion rate was then identified and the corrosion mechanism revealed. The corrosion rate was identified at 4°C, 20°C, 50°C and 80°C and compared with the corrosion rate of WC-Co in seawater. The results revealed that sulphate has an inhibiting effect that minimises the corrosion attack on WC-Co. The corrosion rate decreased as the sulphate content in seawater increased, and an increase in the temperature increased the corrosion attack on WC-Co.

scholarly journals Effect of Microwave Heating on the Dielectric Properties and Components of Iron-Fortified Milk

2017 ◽  
Vol 2017 ◽  
pp. 1-10
Author(s):  
Xiao-shu Tang ◽  
Da-ming Fan ◽  
Feng Hang ◽  
Bo-wen Yan ◽  
Jian-xin Zhao ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Dielectric Properties ◽  
Microwave Heating ◽  
Ionic Form ◽  
Ferrous Chloride ◽  
High Concentration ◽  
Absorption Properties ◽  
Ferrous Gluconate ◽  
Fortified Milk ◽  
Transfer Method

With the iron-fortified milk as research object, this paper makes a research on the influence of iron on the dielectric properties and wave absorption properties and effect of nutritional components, such as casein and whey protein in milk, and thermostability in the process of microwave heating, and rapid heat transfer method in ferrous gluconate–milk and ferrous chloride–milk, respectively. The results show that the iron of ionic form has greater influence to convert microwave to heat energy and the effect of microwave absorption properties was greater for ferrous chloride than for ferrous gluconate at high concentration. The effect of different forms of iron on the composition of milk was different, and the composition of milk systems was more stable by microwave heating, but the rapid heat transfer method is superior in the aim of increasing the nutritional value of milk. The ferrous gluconate–milk system has a better thermal stability than ferrous chloride–milk system. From the aspect of dielectric induction, the paper discovers the response rules of iron and evaluates the microwave thermal safety of the traditional and the iron-fortified products by microwave heating.

Tailored Rheological Behavior of Mullite and BSAS Suspensions Using a Cationic Polyelectrolyte

2005 ◽  
Author(s):  
Glen H. Kirby ◽  
Kevin M. Cooley ◽  
Beth L. Armstrong
Keyword(s):  
Yield Stress ◽  
Rheological Behavior ◽  
Elastic Moduli ◽  
Flow Behavior ◽  
Critical Concentration ◽  
Aqueous Suspension ◽  
Aqueous Media ◽  
Shear Thinning ◽  
Dip Coating ◽  
Cationic Polyelectrolyte

The effects of a cationic polyelectrolyte, polyethylenimine, on the rheological behavior of aqueous mullite and celsian phase, barium strontium aluminosilicate (BSAS) suspensions have been studied to optimize a dip-coating process. The surface of the ceramic particles was characterized in aqueous media using zeta potential measurements. The ionization behavior and hydrodynamic radius of polyethylenimine in aqueous media was characterized by potentiometric titration and dynamic light scattering measurements, respectively. The rheological behavior of concentrated ceramic suspensions containing polyethylenimine was characterized by stress viscometry and elastic modulus measurements. Polyethylenimine imparts repulsive, electrosteric interactions between mullite and BSAS particles in aqueous suspension, resulting in shear thinning flow behavior, linear elastic moduli, and yield stress values that are minimized for suspensions with a critical PEI concentration of 0.2 mg PEI per m2 of mullite and 0.4 mg PEI per m2 of BSAS, respectively. The elastic moduli and yield stress of mullite and BSAS suspensions were nearly identical at equivalent fractions of their critical PEI concentration. Uniform coatings were obtained upon dipping SiC, Si3N4, and Si-metal substrates into shear-thinning suspensions containing PEI at 81–88% of the critical concentration. Dense mullite coatings were demonstrated on SiC substrates after sintering at 1400°C.

scholarly journals Characterization of Pseudomonas bacteria of Piper tuberculatum regarding the production of potentially bio-stimulating compounds for plant growth

2021 ◽  
Vol 51 (1) ◽  
pp. 10-19
Author(s):  
Danyllo Amaral de OLIVEIRA ◽  
Solange da Cunha FERREIRA ◽  
Daiany Larissa Ribeiro CARRERA ◽  
Cleyson Pantoja SERRÃO ◽  
Daihany Moraes CALLEGARI ◽  
...  
Keyword(s):  
Plant Growth ◽  
Black Pepper ◽  
Plant Diseases ◽  
Piper Nigrum ◽  
Soluble Phosphate ◽  
High Concentration ◽  
Molybdenum Blue ◽  
Iaa Production

ABSTRACT Despite advances in the identification and characterization of endophytic bacteria in various plant species worldwide, little is known about such microorganisms in plants from the Amazon region. Previous studies reported that Piper tuberculatum endophytic Pseudomonas (isolates Pt12 and Pt13, identified as Pseudomonas putida and Pseudomonas sp., respectively) were able to inhibit the in vitro growth of Fusarium solani f. sp. piperis, which causes root rot in black pepper (Piper nigrum), and that Pt13 promoted the growth of P. nigrum. Therefore, the aim here was to characterize these bacteria regarding their ability to produce plant growth-promoting substances [siderophores, indol acetic acid (IAA) and soluble phosphate]. Chrome azurol S assays were performed for the detection of siderophores. For qualitative and quantitative assays of IAA production and phosphate solubilization, Salkowski´s reagent and NBRIP medium with molybdenum blue reagent, respectively, were used. Results revealed that Pt12 and Pt13 were able to synthesize IAA, mainly under a high concentration of L-tryptophan, indicating that they are IAA-producing bacteria, probably through a tryptophan-dependent biosynthesis pathway. The presence of P. nigrum extract positively influenced the IAA production by Pt12 and Pt13, with highest values of 125 and 90 µg mL-1, respectively. In addition, Pt12 was positive for the production of siderophores and produced 56.56 µg mL-1 of soluble phosphate. In contrast, Pt13 showed no ability to produce siderophores or to solubilize phosphate. Besides their potential in controlling plant diseases, Pt12 and Pt13 have potential as biofertilizers, favoring sustainable agriculture.

scholarly journals Influence of Aerobic Bacteria Concentration on the Process of its Survival in the Presence of Oxygen

2020 ◽  
Keyword(s):  
Unit Volume ◽  
Aqueous Media ◽  
Oxygen Atmosphere ◽  
Aerobic Bacteria ◽  
Bacterial Cells ◽  
High Concentration ◽  
Aquatic Medium ◽  
Subsequent Decrease ◽  
Before And After ◽  
Number Of Microorganisms

Purpose of the study is to study the viability of aerobic microorganisms in an oxygen atmosphere with different initial content in the aquatic medium. Compare the effect of gas on different concentrations of bacteria per unit volume of the water. Methods. Aerobic bacteria of the genus Bacillus cereus bacteria type were the studied microorganisms. Model aqueous media were created on the basis of distilled deaerated water with the addition of bacteria of a particular type. Oxygen was bubbled into the microbial water throughout the process at a rate of 0.2 cm3/s. The duration of the study was 2 hours, during which the total gas consumption corresponded to 1.4 dm3. The number of microorganisms (NM) before and after the experiments was determined by counting the colonies that grew on the Petri dishes. Results. A two-stage process of oxygen exposure to aerobic bacteria was detected - accumulation and reduction of its number per unit volume of water during all experiments. At the first stage of the process, there was an increase of NM during 1800-3600 s with its subsequent decrease (II stage). With an increase in the microbial load in the water from 102 to 104 CFU/cm3, the duration of the process of bacterial accumulation was decreased in two times. An active reproduction of bacterial cells was investigated at the low concentration of bacteria in the water, and its active reduction - at the high concentration that is explained by cells destruction under conditions of constant supply of oxygen of the established rate. Conclusions. The oxygen influence on the change of the number of aerobic microorganisms in the aquatic medium is explained. It is investigated that the oxygen action on bacteria in the water divides the process of its viability into two stages: accumulation (I stage) and reduction of its number (II stage). It is shown that the duration of the process of bacteria accumulation in the oxygen atmosphere depends on its initial amount in the water, namely with increasing of the initial NM per unit volume of the water, the duration of the stage of microorganisms accumulation decreases significantly.

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