Abstract:
Plant seeds are sources of readily available nutrients and raw materials for man and industries,
respectively. Although commonly regarded as wastes, flours, oils and spent cakes from these seeds
can be used in animal nutrition. While the chemical constituents of Areca catechu-(AC),
Enterolobium cyclocarpum-(EC), Polyalthia longifolia-(PL), Balanites aegyptiaca-(BA) and
Neocarya macrophylla-(NM) seeds are known, there is limited information on the use of their
flours and cakes in dietary feed and their oils as biofuels. The aim of this study was to screen these
seeds for the production of cakes and oils from seeds flours, characterise and evaluate their
applications as feed and oleochemicals.
The AC-(FHI-113371), EC-(FHI-113391) and PL-(FHI-113392) seeds collected from Oyo; BA-
(FHI-113393) (Kaduna) and NM-(FHI-113395) (Niger) were authenticated at FRIN (Ibadan) and
separately pulverised into flours. Oils were extracted using n-hexane and cakes were obtained after
extraction. Proximate compositions of all flours and cakes from only BA and NM were determined
using standard methods. The mineral and amino acids contents were determined using ICP-OES
and HPLC. Fatty-acid profiles of oils were evaluated by flame ionisation gas chromatography.
Wistar rats were fed at 0-30% substitution for 56 days with AC, EC and PL flour formulations as
well as BA and NM oils and cakes formulations, respectively. The control Wistar rats were
maintained on conventional rations. Rat weights were assessed weekly. In vivo toxicity was
determined using Red Blood Cell count (RBC) and tissue histopathology using standard
procedures. The BA and NM oils were converted into biodiesel, biolubricant and biosurfactant
following established procedures. Their chemical conversions were monitored with FTIR and
1HNMR. Their physicochemical properties were evaluated and compared with standard
specifications for automotive fuels-(EN-14214), lubricant-(ISO-VG-32) and surfactant-(SLS).
Data were analysed using ANOVA at α0.05.
The protein contents of the flours were 4.20±0.08, 25.43±0.22, 12.40±0.25, 30.54±0.15 and
30.69±0.05% for AC, EC, PL, BA and NM, respectively. Their respective carbohydrate contents
(%) were 52.58±0.64, 54.66±0.23, 59.65±0.19, 5.08±0.08 and 8.15±0.25. Predominant minerals
(ppm) were K(2116.98±0.01-5767.62±0.11), Ca(503.63±0.03-1225.12±0.02) and
Mg(674.33±0.57-3560.56±0.09). Essential amino acid ranged from 17.93-36.36 g/100g. The oils
were rich in oleic and linoleic acids with cholesterol-lowering activity. A significant increase in
weight (72.86±0.01-96.44±1.01 g) was recorded in Wistar rats maintained on 10% AC-modified
feed compared to other treatments. The RBC ranging from 7.09±0.49 to 7.51±0.58×106 cells/µL
compared favorably with the control (6.66±1.59 to 7.73±0.53×106 cells/µL). The BA intake caused
a mild diffuse hydropic degeneration of rats’ liver cells. The viscosity at 40oC (3.52-4.42; 19.21-
26.64 mm2/s), density at 15oC (0.88-0.89; 0.88-0.92g/cm3) and flash point (139.30-146.51; 220-
240.35oC) of synthesised biodiesel, biolubricant and surface tension (27.45±0.02-
27.90±0.03mN/m) of biosurfactant from BA and NM oils, respectively, compared favourably with
standards. Peaks at 1617cm-1(C=Oamide) and 1060cm-1 (C-Namide) indicated biosurfactant formation,
while those at 3366-3442cm-1 (O-Hstretching) suggested biolubricant formation. A singlet at 3.70ppm
(methoxy-protons) indicated biodiesel formation. These peaks were absent in the spectra of the
oils.
Balanites aegyptiaca and Neocarya macrophylla seeds had good nutritional constituents and could
serve as alternative sources of nutrients in feed formulations if purified. Their oils were potential
raw materials for oleochemicals.
