Bulletin of the National Research Centre (Feb 2019)
Effective treatments of jojoba and jatropha hulls to obtain phytochemical compounds for industrial, nutritional, and pharmaceutical uses
Abstract
Abstract Background In the industry, acid and alkali are used to hydrolyze lignocellulosic materials into cellulose and lignin. The cellulose is to be used in several industries such as the production of bioethanol, in the sugar industry, and as carbonaceous materials in place of bleaching agents. On the other hand, the lignin separated from the lignocellulosic materials is used as a rich source of different bioactive materials. Usually, the alkali and acid hydrolysis are carried out at high temperatures. The aim of this study was to carry the extraction by using ultrasound equipment at low temperatures to save the phytochemicals present. This study was designed to investigate the effect of 12 different treatments on the extraction of bioactive compounds from jatropha and jojoba hulls. These bioactive extracts are examined for their phytochemical content, antioxidant, and antibacterial activities. The free and bounded bioactive compounds from jojoba and jatropha hulls were also considered. From our previous work, we reached the conclusion that a single extraction method is not as effective as a mixture of solvents and extraction processes. Methods The hulls were ground and sieved. The effects of ultrasound-assisted extraction together with soaking afterwards were investigated. Solvents used were (1, 0. 5 N HCl), (1, 0.5 N-NaOH), and (70 ml ethanol mixed with 30 ml of (1, 0. 5) N HCl or NaOH) and then soaking to reduce the temperature and to enhance the process in order to hydrolyze lignin. The phenolic compounds, flavonoids, and saponins in each extract were determined, and their antioxidant activities were evaluated. Three antioxidant activity methods were applied for each extract: hydrogen peroxide (H2O2) radical scavenging activity, DPPH, and total reducing capability. Results Bioactive compounds in their natural form were found to possess high antioxidant activities exceeding that of BHT. The NaOH proved to have a great power for the extraction of phytochemical compounds with elevated antioxidant activities from jojoba, while (1, 0.5 N) HCl with ethanol (30–70%) concentrations extracted phytochemicals with high antioxidant activity from jatropha. Conclusion (A) A simple method for the extraction of flavonoid, phenolic, and saponin compounds from jojoba and jatropha hulls with different activities has been developed. This method utilized a small amount of solvent and less energy. The bioactive extracts can be used in the pharmaceutical industry. (B) Introduce different structure of bioactive compost extracts from jojoba and jatropha hulls through hydrolyses of lignocellulolytic hulls and then the residue will be ready at the same time for multi-uses in industrial purposes.
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