CHITOSAN NANO-ENCAPSULATION OF MICROALGAL Β-CAROTENE: ENHANCEMENT OF STABILITY, BIOACCESSIBILITY, AND IN-VITRO ANTIOXIDANT ACTIVITY

Anssam Hassan Ali

doi:10.70604/jmtbas.v3i2.202

Authors

Anssam Hassan Ali Ministry of Education, General Directorate of Al-Qadisiyah Education, Diwaniyah 58001, Iraq

Abstract

β-Carotene obtained from the halophilic microalga Dunaliella salina is a valued provitamin-A pigment with a strong antioxidant profile, yet its practical use as a functional-food ingredient is limited by poor water solubility, sensitivity to heat, light and oxygen, and a generally low intestinal bioaccessibility. In the present work, microalgal β-carotene was extracted from cultured D. salina and entrapped within chitosan–sodium tripolyphosphate (CS–TPP) nanoparticles produced by the mild ionic-gelation route, with the aim of improving its colloidal stability and its release behaviour in a simulated digestive environment. The optimised particles were characterised for hydrodynamic size, polydispersity, surface charge, encapsulation efficiency and morphology, while chemical interactions and crystallinity were probed by FTIR and XRD. β-Carotene-loaded nanoparticles showed a mean diameter of 247 ± 15 nm, a positive zeta potential of +28.3 ± 2.1 mV and an encapsulation efficiency of 78.6 ± 3.2 %, and they remained dispersible in water, unlike the free pigment. Thermal, ultraviolet and storage assays indicated that encapsulation slowed pigment degradation appreciably. A static INFOGEST-type digestion raised the bioaccessibility of β-carotene from 3.6 % (free) to 24.8 % (encapsulated), and the DPPH, ABTS and FRAP responses of the digested nanoparticles were higher than those of the free pigment. Taken together, the data suggest that chitosan nano-encapsulation is a workable, food-grade strategy for stabilising microalgal β-carotene and improving its functional delivery.

Keywords:

Dunaliella salina, β-carotene, chitosan nanoparticles, ionic gelation, bioaccessibility, in-vitro digestion, antioxidant activity, nanoencapsulation

DOI

https://doi.org/10.70604/jmtbas.v3i2.202

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