scholarly journals Effect of pH and water irradiation with the electromagnetic field on the gelation of gelatin solutions

2020 ◽  
Vol 100 (4) ◽  
pp. 96-103
Author(s):  
I.E. Stas’ ◽  
◽  
S.S. Pavlova ◽  
Keyword(s):  
Electromagnetic Field ◽  
Solid State ◽  
Isoelectric Point ◽  
Physical State ◽  
Relative Viscosity ◽  
Gelatin Solution ◽  
Effect Of Ph ◽  
Structured System ◽  
And Control ◽  
Control Samples

The rate of gelation was determined from the curve slope of the dependence of the gelatin solution relative viscosity on time at different pH. It was found that slow gelation of 2 % gelatin solution occurs at T = 293 K, and the degree of fluidity significantly depends on рН. The most stable jellies are formed at the isoelectric point (рН = 4.7). There are significant differences in the physical state of jellies prepared on irradiated water and control samples. Prepared on unirradiated water jellies are more mobile and retain fluidity at T = 293 K regardless of рН. There is a partial or full melting of the jellies with the increase in temperature at 297 K; however solid state remains for irradiated systems at pH = 4 and 4.7. It was shown that the viscosity of the ir-radiated solution and the rate of its increase are higher in comparison with the control samples at all pH val-ues except рН = 2. The observed phenomenon can be caused by the weakening of the hydration of polymer macromolecules in the activated water, which facilitates their association and the formation of a structured system.

scholarly journals European spruce (Picea abies L.) survival ability and morphological traits of seedlings treated with low-frequency electromagnetic field and planted with hydrogel application

2021 ◽  
Vol 25 ◽  
pp. 22-29
Author(s):  
A.I. Smirnov ◽  
◽  
V.F. Nikitin ◽  
A.A. Generalova ◽  
P.A. Aksenov ◽  
...  
Keyword(s):  
Electromagnetic Field ◽  
Survival Rate ◽  
Picea Abies ◽  
Morphological Traits ◽  
Low Frequency ◽  
Anatomical Structure ◽  
Biometric Analysis ◽  
And Control ◽  
Positive Effect ◽  
Control Samples

The results of the study indicate a clear positive effect of the low-frequency electromagnetic field and hydrogel on the increase in the survival rate of experimental samples of European spruce seedlings (Picea abies L.) treated with BOT technology in relation to the control samples. The results of comparative biometric analysis are presented, which prove the effectiveness of methods of processing spruce seedlings with a low-frequency electromagnetic field and applying hydrogel to the soil. The histometric analysis of experimental and control samples of European Spruce seedlings confirmed the positive effect of the low-frequency electromagnetic field on the anatomical structure of the xylem of seedlings treated using the BOT technology.

Changes in the Population Density of Pathogenic Microorganisms in Response to the Allelopathic Effect of Thypha Latifolia

2014 ◽  
Vol 1 (1) ◽  
pp. 31-36 ◽  
Author(s):  
O. Zhukorskiy ◽  
O. Gulay ◽  
V. Gulay ◽  
N. Tkachuk
Keyword(s):  
Cell Density ◽  
Allelopathic Effect ◽  
Pathogenic Microorganisms ◽  
Sterile Water ◽  
Erysipelothrix Rhusiopathiae ◽  
Pathogenic Leptospira ◽  
Favorable Conditions ◽  
And Control ◽  
The Impact ◽  
Control Samples

Aim. To determine the response of the populations of Erysipelothrix rhusiopathiae and Leptospira interrogans pathogenic microorganisms to the impact of broadleaf cattail (Thypha latifolia) root diffusates. Methods. Aqueous solutions of T. latifolia root diffusates were sterilized by vacuum fi ltration through the fi lters with 0.2-micron pore diameter. The experimental samples contained cattail secretions, sterile water, and cultures of E. rhusiopathiae or L. interrogans. The same amount of sterile water, as in the experimental samples, was used for the purpose of control, and the same quantity of microbial cultures was added in it. After exposure, the density of cells in the experimental and control samples was determined. Results. Root diffusates of T. latifolia caused an increase in cell density in the populations of E. rhusiopathiae throughout the whole range of the studied dilutions (1:10–1:10000). In the populations of the 6 studied serological variants of L. interrogans spirochetes (pomona, grippotyphosa, copenhageni, kabura, tarassovi, canicola), the action of broadleaf cattail root diffusates caused the decrease in cell density. A stimulatory effect was marked in the experimental samples of the pollonica serological variant of leptospira. Conclusions. The populations of E. rhusiopathiae and L. interrogans pathogenic microorganisms respond to the allelopathic effect of Thypha latifolia by changing the cell density. The obtained results provide the background to assume that broadleaf cattail thickets create favorable conditions for the existence of E. rhusiopathiae pathogen bacteria. The reduced cell density of L. interrogans in the experimental samples compared to the control samples observed under the infl uence of T. latifolia root diffusates suggests that reservoirs with broadleaf cattail thickets are marked by the unfavorable conditions for the existence of pathogenic leptospira (except L. pollonica).

scholarly journals Sugar and no sugar added fruit microalgae-enriched jams: a study about their physicochemical, rheological, and textural properties

2021 ◽  
Author(s):  
Zaida Natalia Uribe-Wandurraga ◽  
María Bravo-Villar ◽  
Marta Igual ◽  
Carmen Savall ◽  
Purificación García-Segovia ◽  
...  
Keyword(s):  
Food System ◽  
Textural Properties ◽  
Arthrospira Platensis ◽  
Microalgae Biomass ◽  
Textural Parameters ◽  
Weak Gel ◽  
Biomass Extract ◽  
And Control ◽  
Colour Coordinates ◽  
Control Samples

AbstractJams are preparations of fruits whose main preserving agent is sugar. Due to this, health concerns of consumers have resulted in a sugar reduction, and its replacement using alternative sweeteners and introducing new ingredients enhancing nutritional properties. In this study, four types of fruits jams (plum, strawberry, apple, and peach), with or without sugar, were prepared using two microalgae biomass, Arthrospira platensis (Spirulina) and Chlorella vulgaris, and Dunaliella salina extract as ingredients at different mix levels of concentrations, 0.10%–0.10%–0.05% respectively, for plum; 0.04%–0.00%–0.01 respectively, for strawberry; 0.06%–0.04%–0.00% respectively, for apple and 0.00%–0.01%–0.04% respectively, for peach. Physicochemical, rheological, and textural parameters were evaluated. Substitution of sugar/fructose syrup in the jam’s preparation caused changes in pH values, solid soluble content, and rheological and textural properties compared to sugar jams. Using sugar or sweeteners as isomalt, stevia and sucralose and microalgae biomass or extract showed significant changes in colour coordinates, however, these differences were not perceptible by the human eye. Jams containing microalgae biomass-extract showed higher G', G'', G*, and η* values than their corresponding control samples. All the jams presented weak-gel characteristics, distinguishing fruit jams. However, the results of weak-gel model analysis suggest that the influence of the different ingredients in the food system depends not only on their concentration but also on the interactions in the gel structure. Strawberry and apple jams showed no significant differences between microalgae biomass-extract samples and control samples, for both sugar and no sugar added jams being the best-obtained samples.

scholarly journals The effects of Lactococcus lactis subsp. lactis and its supernatant on some bacteriological and sensory values in Rainbow trout (Onchorhynchus mykiss) fillets

2018 ◽  
Vol 9 (1) ◽  
Author(s):  
Asad Abbaspour Anbi ◽  
Vadood Razavilar ◽  
Moslem Neyriz Naghadehi ◽  
Masoud Seidgar ◽  
Ali Nekuiefard ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Lactococcus Lactis ◽  
Storage Time ◽  
Culture Medium ◽  
Live Cells ◽  
Human Consumption ◽  
Lactococcus Lactis Subsp ◽  
Live Bacteria ◽  
And Control ◽  
Control Samples

Lactic Acid Bacteria (LAB) have a great potential as bio-preservatives. The live cells and supernatant Lactococcus lactis subsp. lactis induced bacteriological changes in Onchorhynchus mykiss fillet by spray and immersion methods was studied during vacuum- packaged storage at 4 °C for 15 days. 40 kg of O. mykiss were prepared from a culture farm in Oshnavieh (Northwest Iran) and 112 fillet samples (100g) were prepared by aseptic method. L. lactis subsp. lactis (PTCC1336) bacteria was cultured in MRS culture medium. Its supernatant (2%, 4%) was extracted and 106 CFUml-1 dilutions of LAB were prepared and tested on the fillets to enhance their shelf life. All samples were evaluated regarding to growth of psychrotrophic, psychrophilic, mesophilic bacteria, molds and yeasts. Four characteristics including of odor, flavor, texture and color of fillets after and before cooking were evaluated for sensory analysis on days 1, 5, 10 and 15 and compared with control samples. The 4% supernatant and live bacteria were more effective than that of 2% and control (P<0.05). The amounts of corrosive bacteria in 4% and live cells in storage time were less than human consumption limits (7log CFUg-1), whereas in control and 2% supernatant treatments were more than that limits. The results showed that increasing the percentage of supernatant was more effective on bacteriologic factors and enhanced sensory characteristics of rainbow trout fillets (P<0.05).

scholarly journals Effect of Different Hydrothermal Treatments (Steam and Hot Compressed Water) on Physical Properties and Drying Behavior of Yellow-Poplar (Liriodendron tulipifera)

2019 ◽  
Vol 69 (1) ◽  
pp. 42-52
Author(s):  
Sohrab Rahimi ◽  
Kaushlendra Singh ◽  
David DeVallance
Keyword(s):  
Mechanical Properties ◽  
High Pressure ◽  
Moisture Content ◽  
Yellow Poplar ◽  
Pressure Steam ◽  
Percent Moisture ◽  
Drying Behavior ◽  
Hot Compressed Water ◽  
And Control ◽  
Control Samples

Abstract Nonchemical high-pressure steam treatments have been intensively researched and commercialized to produce chemical-free wood products with enhanced properties. However, the utilization of high-pressure steam involves vapor-phase reactions using high-temperature steam generated at the expense of high energy input. In this research, influences of reaction media (steam and hot-compressed water) and temperature (100°C and 140°C) during thermal treatment on physical properties and drying behavior of yellow-poplar (Liriodendron tulipifera) heartwood were compared. The length, width, and thickness of the samples were 22.53 mm, 17.18 mm, and 16.72 mm, respectively. After the treatment, the samples were dried under an isothermal temperature condition of 105°C. Data on moisture content and time of drying from drying experiments were fitted with unsteady-state molecular transport equations to calculate overall liquid diffusion coefficients. Dimensions, weight, and true volume of samples were measured for green, thermally treated, and dried samples and the values were used to calculate selected physical characteristics. Additionally, selected mechanical properties were evaluated for samples conditioned to 13 percent moisture content. Results showed that intensified hot-compressed water-treated and control samples had the highest and lowest saturated moisture contents (101% and 44%), respectively, immediately after treatments. Intensified steam-treated and control samples had the highest and lowest total porosity (95% and 82%), respectively. Furthermore, mild hot-compressed water-treated samples showed the greatest compression strength (47.8 MPa) at 13 percent moisture content. Except for steam treatment at 140°C, other treatments significantly decreased the diffusion coefficient. Collectively, samples treated with hot-compressed water at 100°C showed the most improved mechanical properties.

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