Evaluation of two Non-Edible, Wild Indigenous Botswana Crops (Croton megalobotrys (Motsebi/Letsebi/Moshoole) and Ricinus communis (Mokhure)) as Potential Feedstocks for Petroleum and Cosmetic Industries

Abstract

Croton megalobotrys and Ricinus cummunis plants produce high-quality nonedible seed oils at relatively high quantities of 39.65 ± 0.06 % w/w to 53.74 ± 0.04 % w/w. The Iodine values of 85.97 ± 1.62 g I2/100 g to 96.51 ± 1.31 g I2/100 g; the low acid values of 0.96 ± 0.05 mg KOH/g to 5.31 ± 0.76 mg KOH/g; and high saponification values of 139.65 ± 1.06 mg KOH/g to 153.01 ± 1.67 mg KOH/g show that these seed oils can be useful feedstocks in the petroleum, soap, and cosmetics industries. GC-MS results revealed that R. cummunis seed oil is made up of eight (8) fatty acids with the bulk being ricinoleic acid at 81.51 %. Ricinoleic acid is the main fatty acid used in oleochemical industries. C. megalobotrys seed oil is made up of five (5) fatty acids, the most abundant being Linoleic acid which makes up 58.01 % of the seed oil. The other two significant fatty acids in C. megalobotrys seed oil are palmitic and oleic acids at 19.51 % and 18.37 %, respectively. These acids are important as starting materials in soap, cosmetic, and pharmaceutical industries. The fatty acids of the two seed oils absorb light at the ultraviolet region of the electromagnetic spectrum. This means that cosmetic products made from these seed oils will be effective in protecting the human skin against ultraviolet radiation. The FT-IR peaks for the two seed oils show that even though these seed oils are made up of different fatty acids, the active sites of their fatty acids are similar, implying that these seed oils can be used as starting materials in similar industries.