Introduction: The high amounts of polyunsaturated fatty acid (PUFA) in kenaf seed oil (KSO) is susceptible to oxidation. However, KSO is rapidly oxidised due to its high PUFA content.
Methods: In order to prevent oxidation, kenaf seed oil was encapsulated using a co-extrusion technique to produce microencapsulated kenaf seed oil (MKSO). The shell materials used were formulated from alginate with high methoxy pectin and chitosan. MKSO was freeze-dried and in vitro behaviour of MKSO was investigated and compared with oven-dried MKSO. After in vitro digestion, the antioxidant and bioactive compounds in freeze-dried MKSO were investigated.
Results: Freeze-dried MKSO released more oil (95.35%) compared to oven-dried MKSO (83.88%) after in vitro digestion. Total phenolic content (TPC) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities showed decreases, compared to before in vitro digestion while 2,2’-azino-bis(3- ethylbenzothiazoline-6-sulphonic acid) (ABTS) radical-scavenging assay and tocopherol content showed increases in released oil from MKSO after in vitro digestion compared to before in vitro digestion. For phytosterol composition, the decreases in released oil were not significant.
Conclusion: The studies showed that microencapsulation allowed for sitecontrolled oil delivery and protected the bioactive compounds.