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.

Optimization of the Aqueous Decoction Process of Combretum micranthum Leaves

This work proposes to compare the extraction of total polyphenols and the coloring obtained after several series of decoction at 100°C/20min, of whole or crushed leaves of Combretum micranthum. The total phenolic content of the extracts obtained after decoction was determined by Folin’s method. The color parameters were measured using a colorimeter based on the CIELAB system. The analysis of variance (ANOVA) shows significant differences (p 0.05) on different parameters evaluated. The Minitab 19 software was used to classify the extracts according to the color parameters (L, A, and B). The results showed that the maximum of polyphenols (21.67%) was extracted in the crushed leaves after three series of decoctions while with the whole leaves the maximum of 16.17% is obtained after six series of decoctions. The concentration of total polyphenols becomes low from four series of decoctions with 0.146 g·AG·100 g-1 MS. The red and yellow coloring drops respectively by 85 and 69% with crushed leaves and 64 and 21% with whole leaves. The conductivity and the brix of the extracts fall according to the series of decoctions. These results show that for optimal use of C. micranthum leaves in traditional medicine, crushed leaves and three series of decoctions are indicated and sufficient.

Effect of Sodium Carbonate on Extraction by Aqueous Decoction of Total Polyphenols from Crushed and Whole Leaves of Combretum micranthum

Sodium bicarbonate is sometimes used to aid in the extraction of total polyphenols. Its main effect is to increase the pH of the extraction solution. Raising the pH can cause changes in the chemical structure of polyphenols. This can lead to variations in their biological properties, solubility and stability. This work studied the effect of sodium carbonate on the extraction by aqueous decoction of total polyphenols from the leaves of Combretum micranthum. The content of total phenolic compounds in the extracts was estimated by the Folin-Ciocalteu method. The color of the samples was measured using a colorimeter (type: KONICA MINOLTA. Japan) based on the CIELAB color system. The results obtained were subjected to a one-way ANOVA analysis of variance with R software version 3.2.4 Revised (2018) and Minitab-18 software. The results reveal a drop in the concentration of extracted polyphenols proportional to the addition of sodium carbonate, i.e. a drop from 3.30 to 1.04 mg·AG·100 g-1 of extract on whole leaves and 3.921 to 2.551 mg·AG·100 g-1 extract on crushed leaves. On the other hand, the intensity of the coloring of the extracts increases significantly with the addition of sodium carbonate from 0.0 g·L -1 to 0.666 g·L-1.

Secondary Metabolites and Antioxidant Activity of Different Parts of the Baobab Fruit (<i>Adansonia digitata</i>L.)

The objective of this study was to determine the polyphenol, flavonoid and tannin content and the antioxidant power of methanolic extracts from the different parts of the Senegalese baobab fruit. Phytochemical screening revealed the presence of saponosides, tannins, alkaloids, sterols, flavonoids, coumarins and total sugars in all extracts from the fruit parts. The total polyphenol content was determined by the folin-ciocalteu method. This method is based on the quantification of the total concentration of hydroxyl groups present in the extract. In an alkaline medium, the reagent of folin-ciocalteu, oxidizes the phenols to ion phenolates and partially reduces its hetero-polyacids, hence the formation of a blue complex. The absorbance is read at 765 nm against a control. The Flavonoids vere determined using aluminum trichloride and sodium hydroxide. Aluminum trichloride forms a yellow complex with flavonoids and sodium hydroxyde forms a pink complex absorbing in the visible range at 510 nm. The alternative colorimetric method based on reactions with vanillin in an acidic medium made it possible to determine the tannin content. Absorbances were measured at 500 nm. The results show that the methanolic extracts of the fibers and shell have very high polyphenol, flavonoid and tannin contents. In fact, the polyphenol contents of the fiber (159.00 ± 0.93 μg EAG/mg extract) and shell (155.39 ± 0.89 μg EAG/mg extract) were much higher than those of the pulp (27.21 ± 0.26 μg EAG/mg extract) and seeds (18.36 ± 0.07 μg EAG/mg extract). In addition, the flavonoid contents of the fibers (97.64 ± 0.40 μg EQ/mg) and of the shell (86.18 ± 0.46 μg EQ/mg) were higher than those of the seeds (12.82 ± 0.04 μg EQ/mg) and pulp (5.66 ± 0.18 μg EQ/mg). The tannin contents of the fibers (256.65 ± 1.45 μg EC/mg) and of the shell (196.05 ± 25 μg EC/mg) are higher than those of the pulp (103.09 ± 0.62 μg EC/mg extract) and seeds (1.09 ± 0.04 μg EC/mg extract). The antioxidant activity of extracts from different parts of the baobab fruit has Also been achieved using two different methods (DPPH and FRAP). The trapping capacity of the DPPH radical is very advantageous for the fibers (IC50 = 2.27 μg/mL) and the shell (IC50 = 1.52 μg/mL). The FRAP test has shown that the extracts from the shell (18.47 μg/mL) and fibers (20.00 μg/mL) have a greater iron reduction capacity than that of the standard ascorbic acid (45.64 μg/mL).

Impact of Storage Conditions on the Physicochemical Characteristics of Baobab (Adansonia digitata L.) Seed Oil

The evolution of some quality markers of baobab (Adansonia digitata L.) was studied. Baobab oil extracted by pressing was packaged in 30 mL non-amber glass bottles and stored at different temperatures: 20°C, 30°C and 45°C. The physicochemical parameters (acid, peroxide, iodine, saponification, refraction and color indices) were determined during three months’ storage. A significant 5% increase in acid, peroxide and saponification value was observed over time. However, the iodine value decreased. The yellowing and refractive index remained stable while storage at 45°C caused the most significant changes in chemical parameters. The results obtained show that oils stored at 20°C had the lowest acid (2.42 ± 0.26 mg KOH/g) and peroxide (0.82 ± 0.25 mEqO2/Kg) value after three months of follow-up.

Processes for the Clarification of the Crude Oil of Baobab Seeds Extracted by Pressing on Activated Carbon Elaborated from the Capsules of the Fruit (Adansonia digitata L.)

The baobab, Adansonia digitata L. plays an important role in the economy of local populations. The oil from the seeds of the baobab fruit is nowadays highly prized because of its numerous cosmetic and therapeutic applications and its composition of unsaturated fatty acids, sterols and tocopherols. However, unlike refined oils, locally extracted baobab oil has not undergone purification operations to ensure its quality. Only a filtration on special cloths is carried out after decantation. Indeed, the oil obtained after pressing is cloudy because of the presence of various impurities. It therefore requires treatment operations to make it more attractive and of higher quality. Therefore, in order to provide innovative solutions to local companies to improve the quality of vegetable oils, a study of clarification (treatment) of crude oil is necessary. An experimental device has been developed in the laboratory. It includes a glass column and a filter bed of dune sand and activated carbon. This study has shown the efficiency of the experimental device. Indeed, the activated carbon, thanks to its adsorbing power, has allowed a significant decrease in turbidity at the 5% threshold, from 14.61 NTU for the raw oil to 0.08 NTU for the oil filtered on 3% carbon and 0.033 NTU for the oil filtered on 5% carbon. That is to say an abatement higher than 95%. This decrease in turbidity could be correlated with the decrease in brown index from 187.39a for the initial crude oil to 128.53d for the oil treated with 3% activated carbon versus 187.59a for the oil filtered on cloths. The lowest brown index was observed with the filtration using 5% activated carbon (35.99b). Thus, for the yellowness index, only the filtration on 5% charcoal allowed to obtain a significant decrease in yellowness. The yellowing index of the oil with 5% was 44.67b against 79.04a for the oil filtered with 3% activated carbon, 86.33a for the crude oil and 86.46a for the oil filtered on cloths. Finally, the oil sample treated with 5% activated carbon had the clearest clarity than the other samples with a clarity (L) equal to 97.98c against 95.63d for the oil treated with 3% carbon and 94.99b for the oil filtered on filter cloths. According to the results obtained, the experimental device made it possible to obtain a clearer baobab oil with a low brown index, thus improving the sensory quality of the oil.

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.

Effect of Baobab (Adansonia digitata L.) Seeds Washing and Origin on Their Fatty Acids and Phenolic Compounds Oils Content

The aim of the present study was to evaluate the effects of baobab seed washing and origin on the chemical composition of the oil extracted by pressing. Six (6) oil samples were obtained from seeds of three (3) geographical origins. The identification and quantification of fatty acids and the polyphenolic profile were carried out by GC-MS and HPLC-UV, respectively. Analysis of fatty acid methyl esters allowed the identification and quantification of 18 fatty acids. Oils from unwashed seeds were richer in palmitic (C16:0), stearic (C18:0), oleic (C18:1) and arachidic (C20:0) acids. In addition, HPLC-UV analysis at 279 nm shows that oils from unwashed seeds are richer in tyrosol, hydroxytyrosol and caffeic acid. With regard to the polyphenolic profile, gallic acid and quercetin were not detected in these baobab oils. Principal component analysis of fatty acid and phenolic compound content showed that oils from unwashed seeds would best preserve their chemical and associated potential bioactive characteristics.