ANTIOXIDANT PROFILE OF POLYPHENOL-LOADED PECTIN-ALGINATE MICROCAPSULES AND THEIR IN-VITRO RELEASE STUDY

Swetanjana Ghosh and Sauryya Bhattacharyya*

ABSTRACT

A combination of sodium alginate and pectin were used to study the effect on the loading efficiency and the radical scavenging activity of the polyphenols extracted from orange (Citrus sinensis) and lime (Citrus aurantiifolia) peels for the development and characterization of potential gastro-resistant microbeads by ionotropic gelation method. The ratios used were 1:1:1 and 1:1:5 (w/w/w), respectively for alginate, pectin and the polyphenols, separately. Sustain release studies were accomplished using Folin-Ciocalteau assay as well as CUPRAC assay with simulated physiological fluids having pH 1.2, 7.4 and 9.2. Sustain release was maximum for the sample containing orange peel polyphenol at 1:1:5 ratio after 90 minutes interval (ca. 1.18 mg/gm), which was about 42% more than the control (ca. 0.83 mg/gm) at pH 1.2. Efficient release was achieved for both types of microbeads with higher load of the polyphenols. Data obtained from ABTS and DPPH radical scavenging assays indicated that the gelispheres contained highly polar polyphenols in greater proportion. The microencapsulated particles provided an effective protection to polyphenols against any degradation as was elucidated by their swelling and erosion behaviours. The microcapsules described in this study indicated possible application as food additives for incorporation into functional foods.

Keywords: Orange, Lime, Microencapsulation, sustain release, free radical.