African Journal of
Biotechnology

  • Abbreviation: Afr. J. Biotechnol.
  • Language: English
  • ISSN: 1684-5315
  • DOI: 10.5897/AJB
  • Start Year: 2002
  • Published Articles: 12300

Full Length Research Paper

Spectroscopic and chemical analysis of a Nigerian hybrid Hevea Brasiliensis (Rubber) seed oil for product quality assessment in technical applications

Samuel E. Onoji
  • Samuel E. Onoji
  • Biofuels and Renewable Energy Division, Petroleum and Natural Gas Processing Department, Petroleum Training Institute, PMB 20, Effurun, Delta State, Nigeria.
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Sunny E. Iyuke
  • Sunny E. Iyuke
  • Biofuels and Renewable Energy Division, Petroleum and Natural Gas Processing Department, Petroleum Training Institute, PMB 20, Effurun, Delta State, Nigeria.
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Anselm I. Igbafe
  • Anselm I. Igbafe
  • School of Chemical and Petroleum Engineering, Afe Babalola University, PMB 5454, Ado-Ekiti, Nigeria.
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Michael O. Daramola
  • Michael O. Daramola
  • Department of Chemical Engineering, Faculty of Engineering, Built Environment and Information Technology, University of Pretoria, Private Bag X20 Hatfield, Pretoria 0028, South Africa.
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  •  Received: 04 August 2020
  •  Accepted: 04 September 2020
  •  Published: 30 September 2020

Abstract

Rubber seeds from a Nigerian hybrid rubber tree were dried in an oven at 110°C for 2 h to 7 wt% moisture content and cold-screw pressed at 30°C to obtain an oil yield of 28 wt%. Chemical compositional, nuclear magnetic resonance (NMR) and Fourier transform infra-red spectroscopy (FTIR) analyses were conducted on the oil sample extracts. Chemical analysis of the oil indicated iodine value of 136.07 g I2/100 g oil, peroxide value of 9.45 O2/kg oil, saponification value of 189.5 mg KOH/g oil, and confirms its suitability for applications, such as biodiesel production, oleochemicals synthesis, polyurethane composites and water-reducible alkyd resins, pharmaceutical products, plasticizers, adhesives, and surfactants. Rubber seed oil is a promising substitute to linseed oil as semi-drying oil for oily paint formulation. 1H NMR analysis revealed that the fatty acid compositions consist of linoleic acid (34.22 wt%), oleic acid (28.6 wt%), linolenic acid (18.6 wt%), and saturated fatty acids (18.57 wt%). FTIR analysis indicated fingerprint regions of 1461 to 585 cm-1 which can be used to check adulteration of the oil. The NMR spectra (1H and 13C) of the oil are similar to those of other vegetable oils with well-identified peaks and regions that can be used to authenticate the quality of the oil.

 

Key words: Rubber seed oil, characterization, nuclear magnetic resonance (NMR), Fourier transform infra-red spectroscopy (FTIR), quality assessment, technical applications.