Incorporation of natural antioxidants extracted from strawberry, cinnamon, beetroot, and ginger; into virgin coconut oil for expansion of its shelf life

Lipid oxidation significantly deteriorates the quality of edible oils and further leads to changes in flavour, storage properties, and overall nutritional value. Phenolic phytochemicals of strawberry (S), beetroot (B), cinnamon (C), and ginger (G) were extracted into ethanol using the reflux method and evaluated for their total polyphenol content (TPC), total flavonoid content (TFC), and antioxidant potential. These phytochemicals were then incorporated into virgin coconut oil (VCO) as individual antioxidants and combinations, to expand its shelf life and mitigate the negative effects of oxidation. The antioxidant fortified VCO subjected to accelerated oxidation was assessed under the parameters of peroxide value (PV), free fatty acid value (FFA), conjugated dienes (CD), conjugated trienes (CT), and Thiobarbituric acid related substances assay (TBARS) value with comparison to control (VCO), gallic acid, Vitamin E, and BHT. The TPC of strawberry, cinnamon, beetroot, and ginger were 198.00 ± 1.41, 135.00 ± 1.41, 55.00 ± 1.41, and 151.51 ± 0.071 mg GAE/g respectively and their antioxidant potential ranged in the order of S> B> C> G based on their IC50 DPPH value. The PV of (VCO, and VCOGC), VCOSG, VCOSCBG, and VCOBHT have reached the rancid PV of 30–40 meq/Kg range in 12, 24, 48, and 72 h respectively. The FFA of control, VCOVit.E, and VCOBHT was higher than that of VCOGC, VCOSG, and VCOSGBC, after 72 h. The CD and CT values increased with time, similar to PV with storage time. Nevertheless, the combinations SB (1:1) and SGBC (1:1:1:1) at 1500 ppm could be used as natural antioxidant and might be explored to prevent the oxidation of vegetable oils. Therefore, the combination could be used as preservative ingredients in the oil-based food industries