TITLE:
Secondary Metabolites and Antioxidant Activity of Different Parts of the Baobab Fruit (Adansonia digitata L.)
AUTHORS:
Edouard Mbarick Ndiaye, Y. El Idrissi Yousra, Sow Alioune, Nicolas Cyrille Ayessou, Hicham Harhar, Mady Cisse, Mohamed Tabyaoui
KEYWORDS:
Adansonia digitata L., Fruit, Pulp, Seeds, Shell
JOURNAL NAME:
Food and Nutrition Sciences,
Vol.12 No.7,
July
19,
2021
ABSTRACT: 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).