Valorization of Natural Residue into Activated Carbon:Example of the Shells of the African Baobab Fruit(Adansonia digitata)L.

This study deals with the valorization of natural residues into activated carbon prepared from waste“Baobab fruit shell”from the Fatick Region,Senegal.Thus,after the preparation of the baobab shell,a chemical activation with orthophosphoric acid H3PO4(85%)was performed followed by pyrolysis at 530°C.To eliminate possible carbonization residues,the activated carbons were impregnated in 0.1 M hydrochloric acid and/or soda solutions and then washed thoroughly with distilled water to obtain a pH between 6.5 and 7.The latter were then dried in an oven at 105°C for 24 h.A characterization was carried out to determine the moisture content,the ash content,the iodine and methylene blue indices,the surface functions and the pH at zero charge point(pHpzc).The moisture and ash contents were 1.87%and 0.72%,respectively.The iodine and peroxide indices obtained were 939,09 mg/g and 575.73 mg/g,respectively.Surface function analysis by Boehm’s method showed that the acidic functions were higher than the basic functions and their pHpzc was lower than neutrality.The best efficiency of methylene blue removal was 99.75%and was obtained with a mass of 0.150 g of activated carbon,pH equal to 10,an initial concentration of methylene blue of 200 mg/L and a contact time of 35 min.

Improving the Quality of Baobab Oil by Filtration on Activated Carbon from the Fruit Capsules

The baobab, Adansonia digitata L., plays an important role in the economy of local populations. Nowadays, baobab seed oil is highly prized for its many cosmetic and therapeutic applications, and for its composition of unsaturated fatty acids, sterols, and tocopherols. However, it undergoes numerous reactions during production, processing, transport, and storage, leading to undesirable products that make it unstable. The aim of this study was to provide local processors with innovative solutions for the treatment of unrefined vegetable oils. To this end, an experimental device for filtering crude oil on activated carbon made from fruit capsules was designed. The results obtained after the treatment show a significant decrease at (p < 5%) in acid value (1.62 to 0.58 mg KOH/g), peroxide value (4.40a to 0.50c mEqO2/Kg), chlorophyll concentration (1.81 to 0.50 mg/Kg) and primary and secondary oxidation products. According to these results, activated carbon’s adsorptive power eliminates oxidation products and certain pro-oxidants such as chlorophyll, resulting in a cleaner, more stable and better storable oil.

猴面包树果多糖超声辅助提取及其抗氧化活性研究

采用超声波辅助提取法制备猴面包树果多糖。在单因素试验的基础上,通过Box-Behnken方法进行三因素三水平的响应面优化试验,确定最佳提取工艺条件为:料液比1∶33(g/mL),提取温度68℃,提取时间1.5 h,超声功率342 W,提取2次,在此条件下,多糖提取率达到(45.03±0.76)%。通过DPPH·清除试验、ABTS^+·清除试验、还原能力试验对所提多糖的抗氧化活性进行考查,结果显示,在所设浓度范围内,随着质量浓度的增加,其DPPH·清除能力、ABTS^+·清除能力及铁氰化钾还原能力均逐渐增强。猴面包树果多糖对DPPH·清除的半最大效应浓度(concentration for 50%of maximal effect,EC_(50))值为2.53 mg/mL,对ABTS^+·清除的EC_(50)值为5.5 mg/mL。试验结果证明猴面包树果多糖具有较好的体外抗氧化性活性。