Ultrasonic spray-freeze drying of partially purified microbial transglutaminase

Isleroglu, Hilal; Turker, Izzet; Tokatlı, Mehmet; Koç, Banu

doi:10.1016/j.fbp.2018.08.003

Cited by 19 publications

(17 citation statements)

References 57 publications

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“…The hydroxamate method was carried out to determine the enzyme activity in U/mL as previously described by Isleroglu et al . ( 22 ). To calculate the specific enzyme activity in U/g, a modified Bradford protein assay was used as follows: first, Bradford solution was prepared.…”

Section: Methodsmentioning

confidence: 99%

“…The USFD rig was set up according to Isleroglu et al . ( 22 ). A volume of 50 mL of enzyme solution (20%, m/m ) was atomized and droplets were frozen by the nitrogen vapour.…”

Section: Methodsmentioning

confidence: 99%

“…After the volume values were determined for ρ b , the measuring cylinder was tapped 100-150 times until a steady volume was reached to calculate tapped density ( ρ t ). The ρ t of the samples was calculated by dividing the mass of the samples by their tapped volume ( 22 ).…”

Section: Methodsmentioning

confidence: 99%

“…Parallel to this concept, Isleroglu et al . ( 22 ) revealed that the activity of microbial TG was enhanced by ultrasonic atomizing. Furthermore, Ishwarya et al .…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of Process Conditions for Ultrasonic Spray Freeze Drying of Transglutaminase

Isleroglu

Turker

2020

Food technol. biotechnol. (Online)

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In this study, a commercial transglutaminase enzyme was dried using an ultrasonic spray freeze drying method and the effects of the process conditions were optimized to maximize the final transglutaminase activity. Accordingly, process parameters affecting enzyme activity were selected, such as nozzle frequency (48 and 120 kHz), flow rate (2, 5 and 8 mL/min) and plate temperature for secondary drying (25, 35 and 45 °C). Moreover, the effects of different pH values (pH=2.0 and 9.0) and high temperature (80 °C) on enzyme activity, physical properties and particle morphology of transglutaminase were discussed. According to the results, transglutaminase preserved its activity despite ultrasonic spray freeze drying. Sonication enhanced the enzyme activity. Using the desirability function method, the optimum process conditions were determined to be flow rate 3.10 mL/min, plate temperature 45 °C and nozzle frequency 120 kHz. The predicted activity ratio was 1.17, and experimentally obtained ratio was 1.14±0.02. Furthermore, enzyme produced by ultrasonic spray freeze drying had low moisture values (2.92-4.36 %) at 8 h of drying. When the morphological structure of the transglutaminase particles produced by ultrasonic spray freeze drying under the optimum conditions was examined, spherical particles with pores on their surfaces were observed. In addition, flow properties of the transglutaminase powders were considered as fair under most conditions according to the Carr index.

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Section: Methodsmentioning

confidence: 99%

“…The USFD rig was set up according to Isleroglu et al . ( 22 ). A volume of 50 mL of enzyme solution (20%, m/m ) was atomized and droplets were frozen by the nitrogen vapour.…”

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

“…Parallel to this concept, Isleroglu et al . ( 22 ) revealed that the activity of microbial TG was enhanced by ultrasonic atomizing. Furthermore, Ishwarya et al .…”

Section: Introductionmentioning

confidence: 99%

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Evaluation of Process Conditions for Ultrasonic Spray Freeze Drying of Transglutaminase

Isleroglu

Turker

2020

Food technol. biotechnol. (Online)

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“…The frozen particles were subjected to main drying for 12 hours at 1 mbar and then to secondary drying for 4 hours, with a shelf temperature at 30°C under a vacuum of 0.01 mbar. The schematic diagram of the SFD system used in this study was given by Isleroglu et al (2018).…”

Section: Spray-freeze Dryingmentioning

confidence: 99%

Particle Morphology of Spray-Freeze Dried Microencapsulation Agents

2019

JSTR

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Spray-freeze drying (SFD) is a relatively new technique for microencapsulation of heat sensitive products. In SFD process, the solution is sprayed in a cryogenic medium such as liquid nitrogen to form frozen fine droplets. Then, the droplets subjected to freeze-drying under vacuum. The freeze-drying time is comparatively short due to the relatively large surface area achieved by the SFD. In this study, frequently used microencapsulation agents namely maltodextrin, inulin and gum arabic were sprayfreeze dried both individual and in the form of mixtures and the resulting powders were characterized with respect to particle morphologies. Morphology of the particles were observed using Scanning Electron Microscopy (SEM). All the spray-freeze dried particles showed spherical shape, sometimes being slightly aggregated. Regular pore structures originating from the formation of crystals were observed on the surface of the maltodextrin particles, while the gum arabic particles were found to have more irregular and small pores. However, inulin particles were found to have a smoother surface form than others. 204 | P a g e www.iiste.org ConclusionIn this study, maltodextrin, inulin and gum arabic, which are frequently used as microencapsulation agents, were dried by SFD method and the particle morphologies were examined. As a result, all the samples were observed to be in a spherical shape. It was observed that gum arabic particles were larger in size due to higher viscosity of gum arabic, and inulin molecules were smaller and more prone to aggregation. Although different forms of porous structures were observed on the surfaces of maltodextrin and gum arabic particles, inulin particles were found to be smoother. The surface porosity aids in solubilization for rehydration during end use. However, it may not be desirable in the case of protection of a biological activity. Therefore, the microencapsulation agent or mixture to be used should be selected according to the desired final product property.

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Hydrogen production optimization from methanol partial oxidation via ultrasonic sprays using response surface methodology and analysis of variance

Chen

Chiu

Chein

et al. 2022

Intl J of Energy Research

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Hydrogen production via partial oxidation of methanol (POM) in an ultrasonic spray system was studied experimentally, using an h-BN-Pt/Al 2 O 3 catalyst with ultra-low Pt contents (0.2 wt%). The effects of oxygen-to-methanol (O 2 /C) ratio, methanol flow rate, and gas hourly space velocity (GHSV) of air and carrier gas on H 2 yield were examined. Compared to conventional spray systems, the ultrasonic spray system could produce more uniformly dispersed methanol and thus further enhance the POM reaction. The results showed a higher O 2 /C ratio (0.8) enhanced the POM, which poses higher CH 3 OH conversion, higher reaction temperature, and lower CO and CH 4 productions. The CO 2 concentration was mainly affected by GHSV and CH 3 OH flow rate. A higher GHSV led to a quicker retention time for the reactants in the catalyst bed, and a lower CH 3 OH flow rate deteriorates the CO 2 concentration. Based on the Box Behnken design (BBD) from response surface methodology (RSM) and analysis of variance (ANOVA), the optimal operating conditions are found to be O 2 /C ratio = 0.8, CH 3 OH flow rate = 0.7 mL min À1 , and GHSV = 10 000 h À1 . Combining these conditions, the predicted maximum H 2 yield is 1.635 mol‧(mol CH 3 OH) À1 which is close to the experimental value of 1.646 mol‧(mol CH 3 OH) À1 . The RSM and ANOVA not only resulted in a quadratic response surface regression model and significant regression coefficients but also indicated CH 3 OH flow rate being the primary factor.analysis of variance (ANOVA), h-BN-Pt/Al 2 O 3 catalyst, hydrogen production, partial oxidation of methanol (POM), response surface methodology (RSM), ultrasonic sprays

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Ultrasonic spray-freeze drying of partially purified microbial transglutaminase

Cited by 19 publications

References 57 publications

Evaluation of Process Conditions for Ultrasonic Spray Freeze Drying of Transglutaminase

Evaluation of Process Conditions for Ultrasonic Spray Freeze Drying of Transglutaminase

Particle Morphology of Spray-Freeze Dried Microencapsulation Agents

Hydrogen production optimization from methanol partial oxidation via ultrasonic sprays using response surface methodology and analysis of variance

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