| Abstract | U novije vrijeme, prehrambena industrija razvija nove funkcionalne prehrambene proizvode obogaćene različitim bioaktivnim komponentama biljnog podrijetla s pozitivnim utjecajem na zdravlje. No, zbog njihove izrazite nestabilnosti i niske bioraspoloţivosti u organizmu poţeljno ih je zaštititi, a u tu svrhu najčešće se koristi tehnika inkapsulacije aktivnih sastojaka u različite biopolimerne nosače. Cilj ovog rada je ispitati učinkovitost inkapsulacije polifenolnog ekstrakta maslačka (Taraxacum officinale L.) primjenom ionskog geliranja i sušenja raspršivanjem. Kao nosač za imobilizaciju polifenola korišten je pektin te njegove kombinacije s izolatima proteina sirutke te kakaovim prahom, rogačem i zelenom kavom, kao novim inkapsulacijskim materijalima. Formiranim hidrogel česticama i česticama dobivenim sušenjem raspršivanjem ispitana su fizikalno-kemijska svojstva, parametri boje, učinkovitost inkapsulacije polifenola i zadrţavanja antioksidacijskog kapaciteta te profil otpuštanja istih iz čestica u gastrointestinalnim uvjetima. Dobiveni rezultati pokazali su da je dodatak novih materijala u pektinski nosač rezultirao nastajanjem većih, tvrĎih i elastičnijih hidrogel čestica, dok su sustavi dobiveni sušenjem raspršivanjem pokazali visok stupanj kohezivnosti. Znatno veću učinkovitost inkapsulacije ukupnih polifenola pokazali su sustavi dobiveni ionskim geliranjem, od kojih je sustav s dodatkom izolata proteina sirutke imao najveći stupanj zadrţavanja (90,08 %). MeĎu sustavima dobivenim sušenjem raspršivanjem najveći stupanj inkapsulacije ukupnih polifenola imao je sustav pektin-zelena kava (55,16 %). Iako su sustavi dobiveni ionskim geliranjem imali poţeljni kontinuirani profil otpuštanja ukupnih polifenola, kod čestica dobivenih sušenjem raspršivanjem u istom se vremenskom periodu otpustio veći udjel istih, što ukazuje na visoki potencijal obje inkapsulacijske tehnike za imobilizaciju biljnih polifenola. |
| Abstract (english) | Recently, food industry has been developing new functional food products enriched with various bioactive components of plant origin with a positive health impact. However, because of their high instability and low bioavailability in the organism, it is desirable to protect them, and for this purpose, encapsulation of active ingredients in various biopolymer carriers is most often used. The aim of this study is to examine encapsulation efficiency of dandelion (Taraxacum officinale L.) polyphenolic extract using ionic gelation and spray drying. Pectin and its combinations with whey protein isolates, and cocoa powder, carob and green coffee, as new materials, were used as delivery systems for immobilization of active compounds. Formulated hydrogel particles and particles obtained by spray drying were tested for physico-chemical properties, colour parameters, the encapsulation efficiency of polyphenols and the retention of antioxidant capacity, as well as the release profile of evaluated compounds from particles in gastrointestinal conditions. The results showed that the addition of new materials in the pectin carrier resulted in formation of larger, harder and more elastic hydrogel particles, while the systems obtained by spray draying showed a high degree of cohesiveness. Notably higher encapsulation efficiency of total polyphenols showed systems obtained by ionic gelation, of which the system combined with whey protein isolates exhibited the highest degree of retention (90.08 %). Among systems obtained by spray drying, the highest degree of encapsulation of total polyphenols was evaluated in a system pectin-green coffee (55.16%). Although the systems obtained by ionic gelation had a desirable continuous release profile of total polyphenols, the particles obtained by spray drying in the same period released a higher content of total polyphenols, what indicates on high potential for the immobilization of plant polyphenols for both encapsulation techniques. |
