| Abstract | Zbog niske bioraspoloživosti polifenolnih spojeva nakon oralne konzumacije, kao i njihove nestabilnosti tijekom različitih uvjeta proizvodnje, tehnika inkapsulacije posljednih godina nametnula se kao učinkovita tehnika zaštite polifenolnih spoojeva. Cilj ovog rada bio je ispitati potencijal različitih sustava nosača na bazi alginata za inkapsulaciju polifenolnog ekstrakta lista maslačka primjenom ionskog geliranja, uz variranje koncentracije gelirajućeg medija (2% i 3% CaCl2). Kao nosač za imobilizaciju polifenola maslačka korišten je alginat i kombinacije istog s izolatima proteina sirutke (A-IPS) te kakaovim prahom (A-KP) i rogačem, kao novim, do sada ne korištenim materijalima za inkapsulaciju. Dobivenim hidrogel česticama ispitane su fizikalne i morfološke karakteristike, inkapsulacijska učinkovitost i kinetika otpuštanja polifenola i antioksidacijskog kapaciteta u simuliranim gastrointestinalnim uvjetima. Pojačanje alginatnog gela kakaovim prahom i rogačem pokazalo je velik potencijal primjene takvih prirodnih sirovina u svrhu inkapsulacije polifenola. Veća koncentracija gelirajućeg medija (3% CaCl2) rezultirala je smanjenjem veličine i mekšom teksturom čestica, dok je pravilniji, sferični oblik čestica postignut dodatkom 2% CaCl2. Najveću inkapsulacijsku učinkovitost hidroksicimetnih kiselina, kao dominantne skupine polifenola maslačka, imao je sustav A-IPS (95,55-95,81%), praćen sustavom A-KP (91,65-95,70%). Najbolji profil otpuštanja ukupnih polifenola iz čestica, kao i njihov najveći udjel, pokazao je sustav A-KP, gdje se 5,94 mg EGK/g čestica otpuštalo do 130 minute (3% CaCl2) te 5,23 mg EGK/g čestica do 140 minute (2% CaCl2). |
| Abstract (english) | Due to the low bioavailability of polyphenols after oral consumption, as well as their instability during different production conditions, recently encapsulation technique has established as an effective technique for polyphenolics entrapment. The aim of this study was to evaluate the potential of different alginate-based delivery systems for encapsulation of polyphenolic dandelion leaf extract using ionic gelation, and varying concentrations of gelling medium (2% and 3% CaCl2). As a carrier for immobilization of dandelion polyphenols alginate and its combination with whey protein isolates (A-WPI), likewise cocoa powder (ACP) and carob, as new univestigated carriers, was used. Obtained hydrogel particles were investigated for physical and morphological characteristics, encapsulating efficiency and release kinetics of polyphenols and antioxidant capacity in simulated gastrointestinal conditions. Reinforcement of alginate gel with cocoa powder and carob showed a great potential of usage such natural materials for polyphenolic encapsulation purposes. Higher concentration of gelling media (3% CaCl2) resulted with a size reduction and softer texture of particles, while more regular, spherical particles were obtained by adding 2% CaCl2. The highest encapsulation efficiency of hydroxycinnamic acid, as a dominant polyphenolic group of dandelion, revealed delivery system A-WPI (95.55-95.81%), followed by A-CP (91.65- 95.70%). The best release profile of total polyphenols from particles, as well as their content, enabled system A-CP, where 5.94 mg GAE/g of particles was released up to 130 min (3% CaCl2) and 5.23 mg GAE/g of particles up to 140 min (2% CaCl2). |
