Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating Material
Freeze drying was compared with spray drying regarding feasibility to process wild thyme drugs in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration and heat-, ultrasound-, and microwave-assisted extractions. Higher...
| Main Authors: | , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2021-06-01
|
| Series: | Molecules |
| Subjects: | |
| Online Access: | https://www.mdpi.com/1420-3049/26/13/3933 |
| _version_ | 1797528557632618496 |
|---|---|
| author | Aleksandra A. Jovanović Steva M. Lević Vladimir B. Pavlović Smilja B. Marković Rada V. Pjanović Verica B. Đorđević Viktor Nedović Branko M. Bugarski |
| author_facet | Aleksandra A. Jovanović Steva M. Lević Vladimir B. Pavlović Smilja B. Marković Rada V. Pjanović Verica B. Đorđević Viktor Nedović Branko M. Bugarski |
| author_sort | Aleksandra A. Jovanović |
| collection | DOAJ |
| description | Freeze drying was compared with spray drying regarding feasibility to process wild thyme drugs in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration and heat-, ultrasound-, and microwave-assisted extractions. Higher total powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% <i>w</i>/<i>w</i>) provided better TPC recovery by 70% in case of lyophilization and higher total powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53–75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation was distinguished from the others by a higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process mainly affected the position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray-dried formulations compared to freeze-dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and a higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151–223 µm) compared to small microspheres (~8 µm) in spray-dried powder. |
| first_indexed | 2024-03-10T10:01:03Z |
| format | Article |
| id | doaj.art-d0942ba39c4d475fa0af45a9d2971c75 |
| institution | Directory Open Access Journal |
| issn | 1420-3049 |
| language | English |
| last_indexed | 2024-03-10T10:01:03Z |
| publishDate | 2021-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Molecules |
| spelling | doaj.art-d0942ba39c4d475fa0af45a9d2971c752023-11-22T01:59:03ZengMDPI AGMolecules1420-30492021-06-012613393310.3390/molecules26133933Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating MaterialAleksandra A. Jovanović0Steva M. Lević1Vladimir B. Pavlović2Smilja B. Marković3Rada V. Pjanović4Verica B. Đorđević5Viktor Nedović6Branko M. Bugarski7Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, SerbiaFaculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, SerbiaFaculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, SerbiaInstitute of Technical Sciences of SASA, Knez Mihailova 35/IV, 11000 Belgrade, SerbiaFaculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, SerbiaFaculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, SerbiaFaculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, SerbiaFaculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, SerbiaFreeze drying was compared with spray drying regarding feasibility to process wild thyme drugs in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration and heat-, ultrasound-, and microwave-assisted extractions. Higher total powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% <i>w</i>/<i>w</i>) provided better TPC recovery by 70% in case of lyophilization and higher total powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53–75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation was distinguished from the others by a higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process mainly affected the position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray-dried formulations compared to freeze-dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and a higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151–223 µm) compared to small microspheres (~8 µm) in spray-dried powder.https://www.mdpi.com/1420-3049/26/13/3933encapsulationfreeze dryinggelatinpolyphenolsspray drying |
| spellingShingle | Aleksandra A. Jovanović Steva M. Lević Vladimir B. Pavlović Smilja B. Marković Rada V. Pjanović Verica B. Đorđević Viktor Nedović Branko M. Bugarski Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating Material Molecules encapsulation freeze drying gelatin polyphenols spray drying |
| title | Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating Material |
| title_full | Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating Material |
| title_fullStr | Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating Material |
| title_full_unstemmed | Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating Material |
| title_short | Freeze vs. Spray Drying for Dry Wild Thyme (<i>Thymus serpyllum</i> L.) Extract Formulations: The Impact of Gelatin as a Coating Material |
| title_sort | freeze vs spray drying for dry wild thyme i thymus serpyllum i l extract formulations the impact of gelatin as a coating material |
| topic | encapsulation freeze drying gelatin polyphenols spray drying |
| url | https://www.mdpi.com/1420-3049/26/13/3933 |
| work_keys_str_mv | AT aleksandraajovanovic freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial AT stevamlevic freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial AT vladimirbpavlovic freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial AT smiljabmarkovic freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial AT radavpjanovic freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial AT vericabđorđevic freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial AT viktornedovic freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial AT brankombugarski freezevsspraydryingfordrywildthymeithymusserpyllumilextractformulationstheimpactofgelatinasacoatingmaterial |