Enhanced the entrapment and controlled release of Syzygium cumini seeds polyphenols by modifying the surface and internal organization of Alginate-based microcapsules

The main objective of this study is using calcium alginate to encapsulate Syzygium cumini seed polyphenolic extract to maintain its stability and functionality. Calcium chloride was exploited as a cross-linking agent to get the final form as calcium alginate capsules. Two different methods for drying of capsules were conducted; freeze-dried (FD.C) and vacuum dried (D.C). Encapsulation efficiency for FD.C and D.C was 75.96 +/- 0.68% and 70.20 +/- 0.59%, respectively. The scanning electron microscopy (SEM) photographs and the mechanical properties indicated that the polysaccharide networks of D.C were strongly firm to prevent the release of total phenolic content (TPC) in gastric phase. FD.C showed fragile polysaccharide networks however, prevented the release of TPC in gastric phase and exhibited more release of TPC than D.C in intestinal phase. The microencapsulation process improved the thermal stability of the extract with 171.97 degrees C and 180.36 degrees C for FD.C and D.C, respectively. Novelty Impact Statement Sodium alginate in combination with calcium chloride was exploited to fabricate controlled release microcapsules. The fabricated microcapsules physically interacted with Syzygium cumin seeds polyphenols. The polyphenolic microcapsules were characterized with high ability to preserve polyphenols in gastric conditions and admitted with release of polyphenols in intestinal conditions. Moreover, the resulted microcapsules increased the thermal stability of grafted polyphenols. Thus, the obtained results would pave a new technique for medical purposes as controlled release systems or more stable capsules for food additive.