CHEMICAL EVALUATION AND DETERMINATION OF ALPHA-TOCOPHEROL LEVELS OF SELECTED COCONUT OIL SAMPLES MARKETED IN NIGERIA
OLUFUNMILAYO EBUNOLUWA ADEJUMO1,*, CHUKWUDUNMBI FAITH ADIGWE1, ELIZABETH AYODELE POPOOLA1, ADELODUN LAWRENCE KOLAPO2
1. Department of Pharmaceutical and Medicinal Chemistry, Olabisi Onabanjo University, Sagamu, Nigeria.
2. Department of Biological Sciences, Augustine University, Ilara-Epe, Lagos State, Nigeria.
Afr. J Pharm Res Dev; Volume 13(1): 065-075 (2021)
ABSTRACT
In recent years, coconut oil has grown in global popularity due to many health benefits that have been attributed to it. In order to maximize the health and socioeconomic benefits inherent in the coconut value chain, it is important to ascertain that coconut oils that are of adequate standards are marketed. The present study investigated the quality characteristics and α-tocopherol contents in fifteen Nigerian marketed coconut oil samples. The quality characteristics evaluated by standard methods include acid value (AV), free fatty acid (FFA), peroxide value (PV), saponification value (SV), and iodine value (IV). The α-tocopherol content was determined by reverse phase-HPLC method. The α-tocopherol (mg) per serving and % daily value (% DV) was subsequently estimated from the values obtained from chromatographic analysis. The ranges of AV (mgKOH/Kg), FFA (%), IV (gI2/100g), and SV (mgKOH/g) were 1.71 – 16.69, 0.86 – 8.40, 11.41 – 22.37, and 13.94 – 307.40 respectively. Peroxides were not detected in all the samples. The range of α-tocopherol content of the market samples was 0.37 – 1.77 mg/100g. The α-tocopherols (mg) per serving and % DV of the investigated coconut oil samples were 0.05 – 0.25 and 0.33 – 1.66, respectively. The quality characteristics of the samples varied significantly (P< 0.05) across different markets. Based on the results obtained, some market samples of coconut oil failed the critical chemical tests such as acid values, free fatty acid values, iodine values and saponification values. Result of this study suggest that to maximize the health and socioeconomic benefits inherent in the coconut value chain, the Government through her relevant regulatory agencies will need to ensure that coconut oils that are of adequate standards are marketed in Nigeria.
Email of correspondence: funmijumo@oouagoiwoye.edu.ng
KEYWORDS: Coconut oil; Quality tests; Alpha-tocopherol; RP-HPLC; %Daily Value.