Development of edible films with rosemary bioactive compounds (Rosmarinus officinalis L.)

Uslijed sve većih zahtjeva i potraţnje trţišta za prirodnom, sigurnom i visoko- kvalitetnom hranom dugog roka trajanja, tehnološki napredak u razvoju biorazgradivih materijala posljednjih je godina omogućio razvoj inovativnih, funkcionalnih jestivih filmova kao ambalaţnih materijala. U ovom radu ispitana je mogućnost formiranja jestivih filmova od prirodnih biopolimera alginata, kitozana, pektina i proteina sirutke u ekstraktu ruţmarina (Rosmarinus officinalis L.) kao izvoru bioaktivnih sastojaka, a s ciljem proizvodnje jestivih zaštitnih filmova poboljšanih funkcionalnih svojstava. Jestivi filmovi formulirani su od zasebnih, mješavina i slojeva biopolimera, te su karakterizirana njihova osnovna fizikalno-kemijska, vizualna, senzorska i bioaktivna svojstva. OdreĎivanjem udjela suhe tvari, vode, debljine i topljivosti pokazana je ovisnost ovih parametara o vrsti biopolimera, dok način formiranja filmova nije imao značajniji utjecaj na ova svojstva. Senzorskim ocjenjivanjem i kolorimetrijskim mjerenjem najbolja vizualna svojstva pokazali su filmovi proizvedeni od slojeva biopolimera u kombinaciji kitozan-proteini sirutke. S obzirom na bioaktivni sastav formuliranih filmova, utvrĎeno je da filmovi proizvedeni od mješavina biopolimera sadrţe najveće udjele ukupnih polifenola, hidroksicimetnih kiselina te najveći antioksidacijski kapacitet, posebice film proizveden od kombinacije biopolimera alginata i proteina sirutke. Praćenjem profila otpuštanja ukupnih polifenola i antioksidacijskog kapaciteta iz filmova odreĎeno je da filmovi proizvedeni od zasebnog biopolimera kitozana imaju najbolji profil.Due to the growing market demands for natural, safe and high-quality food with prolonged shelf life, technological advances in the development of biodegradable materials enabled the use of innovative, functional edible films as packaging materials over the last years. This thesis examines the possibility of formulating edible films from natural biopolymers such as alginate, chitosan, pectin and whey proteins in rosemary extract (Rosmarinus officinalis L.) as the souce of bioactive ingredients, with the aim of producing edible protective films with improved functional properties. Edible films were formulated from separate, blends and layers of stated biopolymers, and their basic physico-chemical, visual, sensory and bioactive properties were characterized. By assesing the content of dry matter, water, thickness and solubility, the dependence of these parameters on the type of biopolymers was established, while the formulation manner of the films did not have a significant effect on these properties. By sensory evaluation and colorimetric measurements, the best visual properties of films produced from biopolymer layers, especially in combination chitosan-whey proteins were determined. Considering the bioactive composition, it was established that films formulated from biopolymer blends exhibit the highest content of total polyphenols, hydroxcinnamic acids and the highest antioxidant capacity, especially films produced from the combination of alginate and whey proteins. The release kinetics of total polyphenols and antioxidant capacity revealed that the films produced from the separate biopolymer chitosan exhibit the best, prolonged release profile