The potential use of Baobab (Adansonia digitata) Fruit Pulp in Formulation of Functional Food

Abstract

This study aimed to determine the physical characteristics of baobab fruit, phytochemical profile, bioactive components, biological activities, nutritional composition, antioxidant activity and pectin of baobab (Adansonia digitata) fruit pulp and to formulate Baobab fruit pulp based cream cheese as a functional food. In addition the effect of baobab cream cheese on general health of the rats was investigated. Baobab fruits were collected from four locations in Sudan (El Obeid, Um Ruwaba, Nyala and Damazin). The fruit pulp was obtained from baobab pods, then the seeds were removed and pulp powder was sieved using appropriate mesh. The length, width, thickness of fruit , weight of pulp, weight of seed, number of seed, weight of red fiber and weight of epicarp of baobab samples were determined. The proximate composition (moisture, protein, oil, fiber, ash and carbohydrate) of the pulp was analyzed according to AOAC methods, ascorbic acid content was determined using titration method and water based extraction method was used for pectin extraction. Aqueous, ethanolic and methanolic baobab fruit pulp extracts were used to determine the antioxidant activity using DPPH and FRAP methods. Phenolics and flavonoids contents of the extracts were determined spectrophotometrically using Folin–Ciocalteu reagent and aluminium chloride, respectively. Flavonoids and Phenolic profiles of pulp extracts were analyzed by LC-MS/MS. The methanolic extract of baobab pulp was subjected to analysis for alpha-glucosidase, nitric oxide inhibitors. 1H NMR based metabolomics was used to investigate phytochemical constituents. Baobab fruit pulp with the highest content of phytochemical components was used to formulate a novel functional cream cheese supplemented with Bifidobacterium longum BB536. Cream cheese with different concentration of pulp (A: 10%, B: 15% and C: 20%) was prepared using cow milk and analysed for chemical composition, safety, growth of the BB536, and sensory properties .The effect of the formulated XVII baobab cream cheese on intestinal microflora and general health including hematology and blood biochemistry of fed on male Albino rats was investigated. Thirty rats were acclimatized to the experimental condition for fifteen days and randomly distributed into five different groups and received feeding for a period of 30 days. The results of physical characterization, morphological characteristics, approximate composition, sugars (total, reducing, none-reducing), specific sugars (Glucose, fructose, sucrose), and pectin showed highly significant variances (P<0.05) between fruits. Antioxidant activity of baobab pulp was significantly different (P<0.05) between different locations. There were significant differences (P<0.05) in total phenolic and flavonoids contents between extracts from different locations in Sudan. The concentrations of total phenolics ranged from 15.50 to 99.66 mg GA/g of Gallic acid equivalent (GAE) /g and flavonoids contents ranged from 1.03 to 21.53 mg of Catechin CA/g. Phytochemical profiles of baobab pulp was exhibited 22 phenolics, 47 flavonoids, 4 lipids, sugars, organic acid , iridoids , Stilbenes resveratrol derivate, octadecanoic acid and other compounds. Baobab pulp extract showed greater capability in inhibiting the generation of nitric oxide (NO) from the stimulated RAW264.7 cells at 98.45% inhibition (IC50 of 36.55µg/ml) and α-glucosidase enzyme activity (97.94% inhibition, IC50 of 58.59 µg /mL).Metabolites by NMR of baobab pulp extract were showed the abundance of 21 components including carbohydrates, organic acids, vitamin, amino acids, phenolic compounds, alkaloids and fatty acids. Baobab fruit from Damazin has the highest contain of phytochemical components compared with other samples was used for formulation of baobab cream cheese. The nutritional composition of cream cheese was positively affected by addition of baobab pulp. The results obtained on B. longum BB536 viable count revealed significant (P < 0.05) increase in the 15 days of the refrigeration storage; however, the growth decreased at 30 days for all XVIII cream cheese samples. All formulated cheese samples were safe, and E. coli, Staphylococcus aurous, salmonella were not detected. Moreover, formulated cream cheese was accepted by consumer panelists. In vivo experimental rat fed baobab cream cheese did not reveal any side effect on general health, hematology, serum electrolytes and blood biochemistry parameters. Feeding also increased bifidobacteria and lactobacillus of colon but decreased total anaerobes, pathogens staphylococcus, salmonella, and coliform. In conclusion, Sudanese baobab fruit pulp is rich in phenolics, flavonoids, and a potential source of natural antioxidant to benefit health of consumer. Baobab cream cheese exhibited several beneficial positive effects on general health of rats and could have positive effect on general health of humans.