Physicochemical Characteristics and HPLC Determination of Alpha-Tocopherol in Eighteen Edible Vegetable Oils Marketed in Nigeria

Authors

  • Olufunmilayo Ebunoluwa Adejumo Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu Campus, Ogun state, Nigeria
  • Elizabeth Ayodele Popoola Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu Campus, Ogun state, Nigeria
  • Oluyemisi Adebowale Bamiro Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu Campus, Ogun state, Nigeria
  • John Olabanji Daodu Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu Campus, Ogun state, Nigeria
  • Olatunde James Olaitan Department of Pharmaceutical and Medicinal Chemistry, Faculty of Pharmacy, Olabisi Onabanjo University, Sagamu Campus, Ogun state, Nigeria

DOI:

https://doi.org/10.3329/dujps.v20i1.54032

Keywords:

Vegetable oils, physicochemical characteristics, quality assessment, α-tocopherol, RP-HPLC

Abstract

Eighteen brands of vegetable oils available in the local market were extracted with n-hexane before analysis for alpha-tocopherol by RP-HPLC method. The chromatographic separation occurred isocratically with methanol-water [96:4%v/v] at 0.9 ml/min flow rate. Tocopheryl acetate was the internal standard and alpha-tocopherol was eluted at 7.87 min. Free fatty acids value [FFAVs], peroxide value [PV], iodine value [IV] and saponification values [SV] were determined as quality parameters. Calibration curve was linear [r2 0.9969] and the method was precise with relative standard deviation of 0.35% and mean recovery, 87.39%. Alpha-tocopherol concentration ranged from 0-9.22 mg/100g with the highest in Tropical sunflower oil [9.22 mg/100g] and the lowest [1.16 mg/100g] in Laziz oil. Alpha-tocopherol was not detected in unbranded, local palm oil. The calculated percentage daily value [% DV] of vitamin E ranged from 0- 8.60%. Significant difference [p<0.05] between % DV and recommended dietary allowance [RDA] of vitamin E was observed. FFAs and PV ranged from 0.11-0.74% and 0.99-11.55 meq/kg while IV and SV ranged from 26.71-37.03 g/100g and 4.14-43.68 mg KOH/g, respectively. Seventeen samples [94%] were found to be within the acceptable limits while one [6%], failed for both quality parameters and α-tocopherol test. Strict regulatory control is advocated for these oils to safeguard the public health.

Dhaka Univ. J. Pharm. Sci. 20(1): 49-57, 2021 (June)

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Published

2021-06-14

How to Cite

Adejumo, O. E., Popoola, E. A., Bamiro, O. A., Daodu, J. O., & Olaitan, O. J. (2021). Physicochemical Characteristics and HPLC Determination of Alpha-Tocopherol in Eighteen Edible Vegetable Oils Marketed in Nigeria. Dhaka University Journal of Pharmaceutical Sciences, 20(1), 49–57. https://doi.org/10.3329/dujps.v20i1.54032

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