| Abstract | U ovom radu ispitana je mogućnost formiranja jestivih filmova od polimernih hidrokoloidnih materijala (alginata, pektina i kitozana) u ekstraktu kakaove ljuske kao izvoru bioaktivnih sastojaka, s ciljem proizvodnje jestivih zaštitnih filmova poboljšanih funkcionalnih svojstava. Učinak obogaćivanja jestivih filmova polifenolnim spojevima iz ekstrakta kakaove ljuske praćen je usporedbom s kontrolnim filmovima pripremanima u destiliranoj vodi. Pripremljenim filmovima odreĎivana su fizikalna, mehanička i senzorska svojstva, sastav bioaktivnih spojeva prije i nakon sušenja na 60⁰C, antioksidacijski kapacitet te je provedena korelacijska analiza pojedinih svojstava (boja, senzorska i mehanička svojstva). Prema dobivenim rezultatima, proizvedeni su filmovi debljine 30-100 μm, pri čemu je debljina filma ovisila o pripremi u vodi ili ekstraktu, dok udjel vode i suhe tvari primarno ovise o vrsti korištenog hidrokoloidnog polimera. Kontrolni alginatni film pokazao je najbolja mehanička (najveća vlačna čvrstoća - 6,17 N i najmanja deformacija - 0,73 %) i senzorska svojstva, dok je kitozanski film pripremljen u ekstraktu kakaove ljuske imao najlošija navedena svojstva te najveću debljinu (104,67 μm). Pripremom u ekstraktu kakaove ljuske postignuto je povećanje udjela bioaktivnih spojeva (i do 3 puta više) u odnosu na kontrolne filmove, pri čemu su bioaktivna svojstva očuvana i nakon sušenja filmova na 60°C. Obogaćivanjem filmova u ekstraktu kakaove ljuske značajno je povećan udjel bioaktivnih spojeva, ali su narušena fizikalna, mehanička i senzorska svojstva koja su se pokazala boljima za kontrolne filmove (posebice alginatni). |
| Abstract (english) | In this study, the potential of formulating edible films from polymeric hydrocolloid materials (alginate, pectin, chitosan) in cocoa husk extract as the source of bioactive compounds was investigated, in order to produce edible coating films with functional properties. The effect of enrichment with polyphenolic compounds derived from cocoa husk extract was determined by comparing the produced films with control films obtained only in distilled water. For their comparison physical, mechanical and sensory properties, bioactive compounds prior and after drying of films at 60°C and antioxidant capacity were determined, and the relation between specific properties (colour, sensory and mechanical properties) was deduced by correlation analysis. According to the obtained results, edible films were produced with thickness ranging from 30-100 μm, which was primarily in dependance of the preparation mode (in water or cocoa husk extract), while the water and dry matter content were more affected by the employed biopolymer material. Control alginate film generally exhibited the best mechanical (highest tensile strenght - 6,17 N and lowest deformation - 0,73 %) and sensory properties, while the enriched chitosan film prepared in cocoa husk extract exhibited the poorest respective properties and the highest thickness (104,67 μm). By preparing the films in cocoa husk extract a significant increase of bioactive compounds content was achieved (even up to 3-fold higher) in relation to control films, while the bioactive properties remained preserved even after drying of films at 60°C. Enrichment of films in cocoa husk extract enabled to markedly enhance the bioactive content, but it negatively affected the physical, mechanical and sensory properties of produced films, which were better for control films (especially alginate one). |
