Gelatin as a carrier system for delivery of polyphenols compounds

Abstract

In the present study, the influence of different encapsulation techniques (lyophilization and spray drying) on gelatin, as a carrier system for delivery of polyphenols compounds, on wild thyme extracts and on encapsulated extracts was investigated. FTIR analyses has shown the presence of carbohydrates, polysaccharides, polyphenols, flavonoids, monoterpenes and carboxylates in the dried extracts, while FTIR spectrum of the encapsulated extracts has shown almost exclusively gelatin-based stripes, indicating the efficient encapsulation of the active ingredients of the extracts and therefore their protection. Scanning electron microscopy has shown that the lyophilization process produced irregularly shaped particles, while spray drying formed spherical and pseudo-spherical particles with rough surface. Using the method of diffraction of laser light, it has been found that spray dried encapsulate possessed significantly lower particle size and significantly better uniformity in comparison to the lyophilized sample. According to the results obtained in differential scanning calorimetry, endothermic peak of lyophilized gelatin encapsulate appeared at higher temperature, thus it can be concluded that lyophilized sample was more thermostable than spray dried parallel. Additionally, the values of enthalpy of gelatin encapsulates were significantly higher compared to pure extracts, which confirmed the presence of stabilizing interactions between the encapsulated components and a carrier.

U prikazanoj studiji ispitan je uticaj različitih metoda inkapsulacije (liofilizacije i sprej sušenja) na želatin, kao nosač polifenolnih komponenata, na ekstrakte majčine dušice i na njihove želatinske inkapsulate. FTIR analiza je pokazala prisustvo ugljenih hidrata, polisaharida, polifenolnih komponenata, flavonoida, monoterpena i karboksilata u osušenim ekstraktima, dok su FTIR spektri inkapsulata pokazali isključivo trake koje potiču od želatina, što ukazuje na efikasno obavijanje aktivnih komponenata ekstrakata i samim tim njihovu zaštitu. Skenirajuća elektronska mikroskopija je pokazala da proces liofilizacije daje čestice nepravilnog oblika, dok se sprej sušenjem formiraju male čestice sferičnog i pseudo-sferičnog oblika, sa neravnom površinom. Primenom difrakcije laserske svetlosti utvrđeno je da veličina čestica sprej osušenog inkapsulata ima značajno manju vrednost i da je uniformnost značajno veća nego kod liofilizovane paralele. Ispitivanjem termičkih karakteristika, primenom diferencijalne skenirajuće kalorimetrije, pokazano je da se kod liofilizovanog želatinskog inkapsulata endotermni pik nalazi na višoj temperaturi, te se može zaključiti da je pomenuti uzorak termički stabilniji u odnosu na sprej osušen. Dodatno, vrednosti promene entalpije želatinskih inkapsulata ekstrakata bile su značajno veće nego kod čistih ekstrakata, što svedoči o prisustvu stabilizirajućih interakcija između inkapsuliranih komponenata i nosača.