Extending the shelf life of deodorized Aleurites moluccana (Thel Kekuna) oil using phenolic extract from coconut paring residue

Abstract

Aleurites moluccana nuts, known as Thel Kekuna in Sinhala, is a highly underutilized plant in Sri Lanka with great potential to produce oil loaded with numerous compounds, including omega fatty acids and antioxidants that provide health benefits. Natural pungent order is the major drawback of Thel Kekuna oil (KO), which limits its wide usage. The purpose of this study is to deodorize the KO while preserving the shelf life and antioxidant activity of the deodorized oil. The stripping with an activated alumina column was used to absorb the aromatic volatiles in the KO. The ethanolic extract of Coconut Pairing Residue (CPRE) is rich in phenolic antioxidants. Therefore, this study analyzed the effect of CPRE on reducing oxidation and extending the deodorised oil's shelf life. The KO was extracted using the Soxhlet method. The KO yield was calculated. The fatty acid profiles of the crude and stripped oils were analyzed using gas chromatography, while α-tocopherol and β-carotene levels were quantified using high-performance liquid chromatography. Total phenolic content and DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity were investigated. The CPRE 300 μL was added to 3 g of stripped Kekuna oil (CPRE-SKO), and a raincoat test was performed to assess the shelf life. The oil yield was 51.57 ± 0.34% dry weight basis. Palmitic acid (5.39 ± 0.14%), ∝-linolenic acid (20.16 ± 0.05%), linoleic acid (45.84 ± 0.16%) and oleic acid (28.61 ± 0.11%) were identified as the fatty acids. The ∝-tocopherol and β-carotene concentrations were quantified as 34.68 ± 0.73 mg/KO kg and 4.12 ± 0.17 mg/KO kg, respectively. The oxidative stability of the CPRE-SKO was 27.01 hours, whereas the crude oil exhibited stability for only 3.04 hours at 1200C. There was no significant difference in DDPH radical scavenging activity between crude oil and CPRE-SKO (P>0.05). The findings suggest that CPRE can extend the shelf life of deodorized KO and enrich it with antioxidants while enhancing its palatability.