Abstract | S obzirom na tradicionalnu uporabu u narodnoj medicini i bogat bioaktivni sastav, posebice visoki udio polifenola i hidroksicimetnih kiselina, u ovom radu ispitana je mogućnost inkapsulacije bioaktivnih spojeva ekstrakta maslačka primjenom metode ionskog geliranja emulzija kao tehnike inkapsulacije. Kao nosači za inkapsulaciju korišteni su prirodni biopolimerni materijali i njihove kombinacije - alginat, pektin, proteini sirutke i derivati celuloze. Dobivenim česticama ispitana su morfološka svojstva, veličina čestica, udjel vode, inkapsulacijska učinkovitost te otpuštanje u gastrointestinalnim uvjetima. Dobiveni rezultati pokazali su da se ionsko geliranje u emulzijama može primijeniti kao tehnika mikroinkapsulacije budući da su formirane mikročestice veličine ≤ 800 μm. Bolji parametri inkapsulacije (veličina čestica, udjel vode, inkapsulacijska učinkovitost, produljenje otpuštanja) postignuti su primjenom alginata kao nosača u odnosu na pektin. Poboljšanju ispitivanih parametara pridonijelo je i pojačanje alginatnog gela s drugim hidrokoloidima, kao što su proteini sirutke i hidroksi-propil metilceluloza u odnosu na čiste alginatne čestice. Kao optimalni sustav pokazale su se alginatne čestice s proteinima sirutke budući da su poprimile pravilan, sferičan oblik te omogućile najveću inkapsulacijsku učinkovitost ukupnih polifenola – 77,35% i vrlo dobro zadržavanje hidroksicimetnih kiselina – 89,14%. Primjena kombinacije alginata s hidroksi-propil metilcelulozom kao nosačem omogućila je najbolji profil otpuštanja ovih spojeva iz formiranih mikročestica u simuliranim gastrointestinalnim uvjetima (do 130 minuta). |
Abstract (english) | Considering its traditional and widespread use in folk medicine and rich bioactive composition, especially a high content of polyphenols and hydroxycinnamic acid, in this study, the possibility of encapsulation of bioactive compounds of dandelion (Taraxacum officinalis L.) extract by ionic gelation of emulsions as the encapsulation technique was evaluated. Natural biopolymer materials and their combinations – alginate, pectin, whey proteins and cellulose derivatives were used as the carriers for encapsulation. The morphological characteristics, particle size, water content, encapsulation efficiency and release in gastrointestinal conditions were evaluated. The obtained results revealed that the ionic gelation of emulsions can be used as a microencapsulation technique since micro-sized particles ranging ≤ 800 μm were formed. Better encapsulation parameters (particle size, water content, encapsulation efficiency, release kinetics) were achieved using alginate as the carrier material in comparison to pectin. Also, incorporation of other gelling hydrocolloids, such as whey proteins and hydrox-ypropyl methylcellulose in the alginate gel resulted with better parameters in relation to the plain alginate particles. The combination of alginate with whey proteins as the carrier matrix was proved to be the optimal delivery system, since it was characterized by regular, spherical shape and exhibited high encapsulation efficiency of total polyphenols – 77,35% and very good retention of hydroxycinnamic acids – 89,14%. Using alginate in combination with hydroxy-propyl methylcellulose as the carrier enabled the best (prolongued) release profile of these compounds from the formed microparticles in simulated gastrointestinal fluids (up to 130 minutes). |