{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,29]],"date-time":"2026-08-29T16:31:30Z","timestamp":1788021090954,"version":"build-2784847793"},"reference-count":43,"publisher":"MDPI AG","issue":"13","license":[{"start":{"date-parts":[[2021,6,28]],"date-time":"2021-06-28T00:00:00Z","timestamp":1624838400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004564","name":"Ministarstvo Prosvete, Nauke i Tehnolo\u0161kog Razvoja","doi-asserted-by":"publisher","award":["III46010"],"award-info":[{"award-number":["III46010"]}],"id":[{"id":"10.13039\/501100004564","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>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% w\/w) 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\u201375 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\u2013223 \u00b5m) compared to small microspheres (~8 \u00b5m) in spray-dried powder.<\/jats:p>","DOI":"10.3390\/molecules26133933","type":"journal-article","created":{"date-parts":[[2021,6,28]],"date-time":"2021-06-28T11:45:40Z","timestamp":1624880740000},"page":"3933","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":37,"title":["Freeze vs. Spray Drying for Dry Wild Thyme (Thymus serpyllum L.) Extract Formulations: The Impact of Gelatin as a Coating Material"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-5394-0125","authenticated-orcid":false,"given":"Aleksandra A.","family":"Jovanovi\u0107","sequence":"first","affiliation":[{"name":"Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Steva M.","family":"Levi\u0107","sequence":"additional","affiliation":[{"name":"Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Vladimir B.","family":"Pavlovi\u0107","sequence":"additional","affiliation":[{"name":"Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Smilja B.","family":"Markovi\u0107","sequence":"additional","affiliation":[{"name":"Institute of Technical Sciences of SASA, Knez Mihailova 35\/IV, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rada V.","family":"Pjanovi\u0107","sequence":"additional","affiliation":[{"name":"Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Verica B.","family":"\u0110or\u0111evi\u0107","sequence":"additional","affiliation":[{"name":"Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Viktor","family":"Nedovi\u0107","sequence":"additional","affiliation":[{"name":"Faculty of Agriculture, University of Belgrade, Nemanjina 6, 11080 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Branko M.","family":"Bugarski","sequence":"additional","affiliation":[{"name":"Faculty of Technology and Metallurgy, University of Belgrade, Karnegijeva 4, 11000 Belgrade, Serbia"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2021,6,28]]},"reference":[{"key":"ref_1","first-page":"3","article-title":"Biological activity and ethnomedicinal use of Thymus vulgaris and Thymus serpyllum","volume":"33","author":"Bugarski","year":"2013","journal-title":"Lek. Sirovine (Nat. Med. Mater.)"},{"key":"ref_2","first-page":"101978","article-title":"Review of ethnobotanical, phytochemical, and pharmacological study of Thymus serpyllum L.","volume":"2015","year":"2015","journal-title":"Evid. Based Complement. Altern. Med."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"510","DOI":"10.1016\/j.tifs.2010.08.003","article-title":"Encapsulation of polyphenols\u2014A review","volume":"21","author":"Fang","year":"2010","journal-title":"Trends Food Sci. Technol."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"793","DOI":"10.3390\/pharmaceutics3040793","article-title":"Encapsulation of natural polyphenolic compounds: A review","volume":"3","author":"Munin","year":"2011","journal-title":"Pharmaceutics"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"1710","DOI":"10.1111\/jfpp.12402","article-title":"Freeze-drying for microencapsulation of turmeric oleoresin using modified starch and gelatin","volume":"39","author":"Malacrida","year":"2014","journal-title":"J. Food Process. Preserv."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1016\/j.colsurfa.2012.07.010","article-title":"Microencapsulation of oil droplets using freezing-induced gelatin\u2013acacia complex coacervation","volume":"411","author":"Nakagawa","year":"2012","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"379","DOI":"10.1016\/j.ijbiomac.2016.01.011","article-title":"Microencapsulation optimization of natural anthocyanins with maltodextrin, gum arabic and gelatin","volume":"85","author":"Mahdavi","year":"2016","journal-title":"Int. J. Biol. Macromol."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"1556","DOI":"10.1002\/app.23435","article-title":"Interaction of functional groups of gelatin and montmorillonite in nanocomposite","volume":"101","author":"Xu","year":"2006","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"369","DOI":"10.1016\/j.seppur.2017.01.055","article-title":"Optimization of the extraction process of polyphenols from Thymus serpyllum L. herb using maceration, heat- and ultrasound-assisted extraction","volume":"179","author":"Bugarski","year":"2017","journal-title":"Sep. Purif. Technol."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"89","DOI":"10.1016\/j.seppur.2016.01.019","article-title":"Optimization of microwave-assisted extraction of total polyphenolic compounds from chokeberries by response surface methodology and artificial neural network","volume":"160","year":"2016","journal-title":"Sep. Purif. Technol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"655","DOI":"10.1002\/ptr.1651","article-title":"The effect of freeze-drying and its implications for botanical medicine: A review","volume":"19","author":"Abascal","year":"2005","journal-title":"Phytother. Res."},{"key":"ref_12","unstructured":"Wang, B. (2015). Development of Spray Drying Technology for Microencapsulation of Bioactive Materials. [Ph.D. Thesis, Graduate Faculty of Auburn University]."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"2858","DOI":"10.1007\/s11947-012-0791-z","article-title":"Comparison of conventional and ultrasound assisted extraction techniques of yellow tea and bioactive composition of obtained extracts","volume":"5","author":"Jambrak","year":"2012","journal-title":"Food Bioprocess Technol."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"892","DOI":"10.1016\/j.chroma.2008.12.006","article-title":"On-line coupled dynamic sonication-assisted extraction-liquid chromatography for the determination of phenolic acids in Lamiaceae herbs","volume":"1216","author":"Kivilompolo","year":"2009","journal-title":"J. Chromatogr. A"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"585","DOI":"10.1016\/j.foodchem.2014.06.066","article-title":"Optimization of microwave-assisted extraction of polyphenols from Myrtus communis L. leaves","volume":"166","author":"Dahmoune","year":"2015","journal-title":"Food Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"83","DOI":"10.1016\/j.indcrop.2015.04.035","article-title":"Extraction of phytocompounds from medicinal plant Clinacanthus nutans Lindau by microwave-assisted extraction and supercritical carbon dioxide extraction","volume":"74","author":"Mustapa","year":"2015","journal-title":"Ind. Crop. Prod."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"4918","DOI":"10.1016\/j.chroma.2010.11.055","article-title":"Chemical composition of bioactive pressurized extracts of Romanian aromatic plants","volume":"1218","author":"Miron","year":"2011","journal-title":"J. Chromatogr. A"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"13","DOI":"10.1016\/j.vibspec.2006.06.001","article-title":"Identification and quantification of valuable plant substances by IR and Raman spectroscopy","volume":"43","author":"Schulz","year":"2007","journal-title":"Vib. Spectrosc."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"637","DOI":"10.1016\/j.foodchem.2011.04.105","article-title":"Determination of total phenolic content and antioxidant capacity of onion (Allium cepa) and shallot (Allium oschaninii) using infrared spectroscopy","volume":"129","author":"Lu","year":"2011","journal-title":"Food Chem."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2444","DOI":"10.1007\/s11947-015-1592-y","article-title":"Efficiency assessment of natural biopolymers as encapsulants of green tea (Camellia sinensis L.) bioactive compounds by spray drying","volume":"8","author":"Komes","year":"2015","journal-title":"Food Bioprocess Technol."},{"key":"ref_21","first-page":"415","article-title":"Infrared spectrum analysis of some flavonoids","volume":"58","author":"Heneczkowski","year":"2001","journal-title":"Acta Pol. Pharm. Drug Res."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"558","DOI":"10.1016\/j.matchemphys.2011.04.068","article-title":"Sunlight based irradiation strategy for rapid green synthesis of highly stable silver nanoparticles using aqueous garlic (Allium sativum) extract and their antibacterial potential","volume":"129","author":"Rastogi","year":"2011","journal-title":"Mater. Chem. Phys."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"26496","DOI":"10.1039\/C5RA02566D","article-title":"Polyphenol-gelatin nanoparticles as reductant and stabilizer for one-step synthesis of gold nanoparticles and their interfacial behavior","volume":"5","author":"Jin","year":"2015","journal-title":"RSC Adv."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"E79","DOI":"10.1002\/app.36590","article-title":"On the characterization of sodium alginate\/gelatine-based hydrogels for wound dressing","volume":"126","author":"Saarai","year":"2012","journal-title":"J. Appl. Polym. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"136","DOI":"10.1002\/jbm.a.30168","article-title":"Hydroxyapatite and gelatin composite foams processed via novel freeze-drying and crosslinking for use as temporary hard tissue scaffolds","volume":"72","author":"Kim","year":"2005","journal-title":"J. Biomed. Mater. Res. Part A"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"179","DOI":"10.1002\/jps.20630","article-title":"Infrared microscopy for in situ measurement of protein secondary structure during freezing and freeze-drying","volume":"96","author":"Schwegman","year":"2007","journal-title":"J. Pharm. Sci."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"199","DOI":"10.1248\/cpb.52.199","article-title":"Protection of protein secondary structure by saccharides of different molecular weights during freeze-drying","volume":"52","author":"Izutsu","year":"2004","journal-title":"Chem. Pharm. Bull."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"1759","DOI":"10.1007\/s11947-012-0844-3","article-title":"Effects of spray drying and freeze drying on the properties of protein isolate from rice dreg protein","volume":"6","author":"Zhao","year":"2013","journal-title":"Food Bioprocess Technol."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"222","DOI":"10.2298\/HEMIND0704222M","article-title":"Extraction of green tea and drying with a high pressure spray process","volume":"61","author":"Calderas","year":"2007","journal-title":"Hem. Ind."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"139","DOI":"10.1111\/j.1365-2621.1985.tb13295.x","article-title":"A scanning electron microscopy study of microencapsulation","volume":"50","author":"Rosenberg","year":"2010","journal-title":"J. Food Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"8004","DOI":"10.1021\/jf100925j","article-title":"Characterization and singlet oxygen quenching capacity of spray-dried microcapsules of edible biopolymers containing antioxidant molecules","volume":"58","author":"Faria","year":"2010","journal-title":"J. Agric. Food Chem."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"664","DOI":"10.1016\/j.jfoodeng.2005.05.062","article-title":"Study on microencapsulation of lycopene by spraydrying","volume":"76","author":"Shu","year":"2006","journal-title":"J. Food Eng."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"5984","DOI":"10.1016\/j.gca.2008.10.010","article-title":"The non-oxidative dissolution of galena nanocrystals: Insights into mineral dissolution rates as a function of grain size, shape, and aggregation state","volume":"72","author":"Liu","year":"2008","journal-title":"Geochim. Cosmochim. Acta"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"1161","DOI":"10.1007\/s10973-013-3166-4","article-title":"Thermal transitions of gelatin evaluated using DSC sample pans of various seal integrities","volume":"114","author":"Mukherjee","year":"2013","journal-title":"J. Therm. Anal. Calorim."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"277","DOI":"10.1016\/j.ijpharm.2007.12.020","article-title":"Novel gelatin microcapsule with bioavailability enhancement of ibuprofen using spray-drying technique","volume":"355","author":"Li","year":"2008","journal-title":"Int. J. Pharm."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"524","DOI":"10.1016\/j.carbpol.2013.09.083","article-title":"Gum arabic\/starch\/maltodextrin\/inulin as wall materials on the microencapsulation of rosemary essential oil","volume":"101","author":"Fernandes","year":"2014","journal-title":"Carbohydr. Polym."},{"key":"ref_37","first-page":"189","article-title":"Extraction of phenolics from citrus peels: II","volume":"48","author":"Li","year":"2006","journal-title":"Enzyme-assisted extraction method. Sep. Purif. Technol."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"36","DOI":"10.1016\/j.jff.2015.11.039","article-title":"Biological potential of puffballs: A comparative analysis","volume":"21","author":"Vunduk","year":"2016","journal-title":"J. Funct. Foods"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1021\/ac60111a017","article-title":"Colorimetric method for determination of sugars and related substances","volume":"28","author":"DuBois","year":"1956","journal-title":"Anal. Chem."},{"key":"ref_40","unstructured":"Kruger, N. (1994). Methods in Molecular Biology, Basic Protein and Peptide Protocols, Humana Press."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1231","DOI":"10.1016\/S0891-5849(98)00315-3","article-title":"Antioxidant activity applying an improved ABTS radical cation decolorization assay","volume":"26","author":"Re","year":"1999","journal-title":"Free Radic. Biol. Med."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"441","DOI":"10.1016\/j.foodchem.2008.12.022","article-title":"The composition of polyphenols and methylxanthines in teas and herbal infusions","volume":"115","author":"Komes","year":"2009","journal-title":"Food Chem."},{"key":"ref_43","unstructured":"(2014). European Pharmacopeia, European Directorate for the Quality of Medicines & HealthCare of the Council of Europe. [8th ed.]."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/13\/3933\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T06:25:29Z","timestamp":1760163929000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/26\/13\/3933"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2021,6,28]]},"references-count":43,"journal-issue":{"issue":"13","published-online":{"date-parts":[[2021,7]]}},"alternative-id":["molecules26133933"],"URL":"https:\/\/doi.org\/10.3390\/molecules26133933","relation":{"has-preprint":[{"id-type":"doi","id":"10.20944\/preprints202105.0358.v1","asserted-by":"object"}]},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,6,28]]}}}