In-vitro evaluation of kenaf seed oil in chitosan coated-high methoxyl pectin-alginate microcapsules

Kenaf seed oil was encapsulated using co-extrusion technology with the shell formulation of high methoxyl pectin (HMP)-alginate solution and a chitosan coating was applied additionally on the microcapsules. An in vitro digestion was used to simulate the human gastrointestinal (GI) digestion to examine the oil release behavior of chitosan-coated microencapsulated kenaf seed oil (CMKSO) and non-coated microencapsulated kenaf seed oil (NMKSO). The changes in antioxidant activities and bioactive compounds of kenaf seed oil in CMKSO before and after digestion were evaluated. The best CMKSO with the highest microencapsulation efficiency was obtained from the concentration of 0.1% w/v chitosan solution, which was hardened through one-step process. The results showed that CMKSO was more resistant to simulated gastric fluid than NMKSO. There was 83.33% of kenaf seed oil released from CMKSO after simulated digestion. Enzymatic breakdown of the GI digests decreased the total phenolic content (47.5% decrease) and phytosterols content (35.4% decrease), but increased their 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity (145.1% increase), 2,2′-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS+) (120.9% increase) radical scavenging activity, and tocopherols content (32.1% increase), compared to the undigested kenaf seed oil. This work showed that the microencapsulation of kenaf seed oil with HMP-alginate and a chitosan coating offers an effective controlled release delivery system.