Chemical modification of Na-alginate by octenyl succinic anhydride and its complex with whey protein isolate to encapsulate jujube extract: physicochemical, morphological, thermal and structural properties.

The importance of protecting valuable phenolic compounds causes the need for coatings with greater resistance, for which chemical modification is used. Encapsulation of jujube extract in sodium alginate/whey protein isolate (WPI) and modified sodium alginate/whey protein isolate beads (modified with Octenyl Succinic Anhydride (OSA)) was studied. Total phenolic compounds of the jujube extract, some physical and structural properties of the beads were measured. The highest content of total phenol in modified beads at ambient temperature was 91.2 mg/l (first day). The highest efficiency was observed in the alginate/WPI beads stored at ambient temperature on the 14th day which was 14.91%. The hardness of the beads was also affected by the modification (from 0.99 to 1.26 N). The higher Tg which ensures higher stability in thermal procedure was revealed in the modified beads (77.23°C). FTIR revealed hydroxyl groups related to the jujube extract, gum and whey protein-induced intramolecular beta-sheets. These results are very important in the construction of protective systems and delivery of biological compounds of jujube extract for use in the production of novel functional foods and beverages. [ABSTRACT FROM AUTHOR]