Protection of biodiesel and oil from degradation by natural antioxidants of Egyptian Jatropha

Abstract

AB STRACT:Residue of methanolic extract of Egyptian Jatropha curcas contains bioactive substances such as phenolic compounds, which succeeded to be used as natural antioxidants for the protection of oils and their corresponding biodiesel against oxidative deterioration. In the present work, the residue of Jatropha roots were extracted with methanol and resulting residues, were investigated regarding their content of total phenolic compounds by folin-Cioalteau assay. Further, the antioxidant activities of the extracts were characterized by the 2,2-diphenyl-1-picrylhydrazyl radical method and proved remarkable results. Oxidation stability of Jatropha oil, used fried oil and olive oil and their corresponding biodiesel obtained by conventional transesterification were tested using thermal oxidation. Natural antioxidants such as (α-trocopherol), synthetic antioxidants as butylated hydroxytoluene and natural Jatropha root extract were used in the present study in comparison to investigate their addition effect on the oxidative stability of oils and their corresponding biodiesel. In the rapied thermal treatment test, results showed that addition of butylated hydroxytoluene 0.25 % was able to stabilize Jatropha oil 6 h, but poorly stabiliz biodiesel. Addition of 0.25 % α-trocopherol to Jatropha oil showed less oxidation stability after 2 h thermal treatment. Crude root extract addition at 0.25% to Jatropha oil showed good stability up to 4 h thermal treatment while addition of root extract at 0.25 % to biodiesel showed better stability up to 6 h thermal treatment. Besides addition of 220 ppm crude root extract to biodiesel was enough sufficient to occure oxidative stabilization. Also Jatropha root residue addition at 400 ppm was effective antioxidant for fresh Jatropha oil.

Total Phenolic Contents and Free Radical Scavenging Activity of Different Parts of Jatropha Species

“…Moreover, non-antioxidant compounds may also interference the antioxidant activity [31]. Present work showed the favourable results with previous studies on the leaves of Jatropha [8,[15][16][17][18][19][20] and showed equivalent or higher antioxidant activity. As commented before, not only the species but also the extraction protocols used might affect the antioxidant activities.…”

“…), phenolic content, and others bioactivities of different parts of Jatropha [4][5][6][7]9,10]. On the contrary, few studies have focused on leaves [4,8,[15][16][17], roots [17], fruits [18] and others parts [19][20][21] of Jatropha. However, some studies suggested that leaves exhibited higher phenolic content and antioxidant capacity as against to others parts due to phenolic compounds [15][16][17][18][19][20].…”

“…On the contrary, few studies have focused on leaves [4,8,[15][16][17], roots [17], fruits [18] and others parts [19][20][21] of Jatropha. However, some studies suggested that leaves exhibited higher phenolic content and antioxidant capacity as against to others parts due to phenolic compounds [15][16][17][18][19][20]. Concomitantly, roots of J. gossypiifolia displayed stronger antioxidant activity by both the mechanisms of single electron transfer and hydrogen atom transfer [22].…”

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“…Jatropha curcas is a nut belonging to the Euphorbiaceae family. It is cultivated in central and south America, Southeast Asia, India and Africa and grow well under adverse climatic conditions 8 .…”

Effect of Selected Metal Contaminants on the Stability of Castor Oil Methyl Ester

“…During this stage, up to 100 new radicals are created from one single radical, meaning that the decomposition occurs at an exponential rate and results in the formation of byproducts [15].…”