High-intensity ultrasound processing of baobab fruit pulp: Effect on quality, bioactive compounds, and inhibitory potential on the activity of α-amylase and α-glucosidase

Effect of high-intensity ultrasound (HIU) compared with thermal treatments on baobab fruit pulp (BFP) quality and bioactive properties were investigated. HIU treatments, particularly at intensities of 687.5 W/cm² for 5 min, and 344 W/cm² for 15 min significantly (p < 0.05) increased the cloudiness index, ascorbic acid (AA) retention, total phenolic and flavonoid contents, and antioxidant capacity besides a more potent α-amylase and α-glucosidase inhibition relative to thermally treated samples. Moreover, the physicochemical parameters, colour index, and browning index were maintained with HIU besides lower 5-hydroxymethylfurfural values than thermal processing. HPLC analysis revealed that the content of most phenolic compounds was the highest in HIU treatments besides a 235-256% increase in procyanidin C₁ compared with control samples. The AA retention following HIU treatments was 87.62-102.86% compared to 30.47-61.90% in thermally treated samples. Our analyses portrayed ultrasound as a feasible alternative to conventional thermal processing of BFP.

Comprehensive metabolomic, lipidomic and pathological profiles of baobab (Adansonia digitata) fruit pulp extracts in diabetic rats

Baobab fruit pulp Adansonia digitata (AD) has received attention due to its numerous nutritional and medicinal values. In the current study, tentative identification was performed due to limited information available on its phytochemical composition. Phytochemicals from AD fruit pulp were obtained using successive organic solvent fractionation. The LC-MSMS analysis led to identification of 91 metabolites from methanol, butanol and ethyl acetate extracts. Moreover, 20 compounds were identified in the petroleum ether extract based on high resolution ion masses. In vitro antidiabetic and antioxidant properties of selected extracts were investigated using enzyme activity and the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method, respectively. Biological screening of the antidiabetic effects of target extracts was performed against streptozotocin-induced diabetes in experimental animals, following daily oral treatment for 3 successive weeks. Serum glucose, insulin, adiponectin, superoxide dismutase (SOD), lipid peroxide, cholesterol and HDL levels were measured. Finally, histopathological and immunohistochemical examinations of pancreas were carried out. Results revealed that animal groups treated daily with butanol (BuOH) and petroleum ether extracts of AD (oil) exhibited a significant improvement in carbohydrate and lipid metabolism as well as antioxidant effect. Both extracts revealed superior effects with respect to the total (TT) and ethyl acetate (EtOAc) extracts. Histopathological and immunohistochemical findings supported these results, showing marked protection of the pancreas. Thus, baobab oil and butanolic extract of the fruit pulp protected animals against STZ-induced diabetic changes, in addition to attenuation of lipid peroxidation, hypercholesterolemia and oxidation.

Ultrasound-assisted adsorption/desorption for the enrichment and purification of flavonoids from baobab (Adansonia digitata) fruit pulp

This work described the purification and enrichment of flavonoids from baobab (Adansonia digitata) fruit pulp (BFP) by ultrasound-assisted adsorption/desorption procedure using macroporous resins. Four resins were tested and HPD-500 polar resin exhibited the best adsorption/desorption properties. Based on preliminary experiments and literature reports, the effects of various ultrasonic conditions including high power short time (HPST, 540 W for 5 min), medium power medium time (MPMT, 270 W for 15 min) and low power long time (LPLT, 45 W for 30 min) as well as different temperatures (T = 25-45 °C) on the adsorption of Total Flavonoids Content (TFC) were investigated in comparison with orbital shaking/no sonication (NS). Also, the effect of ultrasound on the desorption capacity and recovery of TFC was determined at different concentrations of ethanol (30-100%). Remarkably, ultrasonic treatment significantly increased the adsorption/desorption capacity and recovery and shortened the equilibrium time. The pseudo-second-order kinetic and Freundlich isotherm models better delineated the adsorption process under ultrasound. Moreover, the adsorption process was both spontaneous and thermodynamically favourable with physical adsorption and multilinear intraparticle diffusion being the predominant mechanisms of the whole process. HPST treatment at 25 °C with 80% ethanol as the desorption solvent most noticeably enhanced the adsorption/desorption of flavonoids and contributed to the highest recovery of TFC, Total Phenolic Content (TPC), and antioxidant capacity in addition to a 5-8-fold reduction in total sugar and acid contents when compared with NS treatment. Moreover, HPLC analysis revealed that the content of nine out of thirteen phenolic compounds from the HPST treatment was the highest, and the individual flavonoids content increased by 2-3-fold compared with the other treatments. Our analyses suggested that ultrasound can be employed as a practical approach to intensify the adsorption and desorption of functional compounds in BFP.

Quality attributes of Kisra prepared from sorghum flour fermented with baobab fruit pulp flour as starter

Kisra, a fermented sorghum flat bread, was prepared from two sorghum genotypes termed Wad-Ahmed (high tannin) and Tabat (low tannin) in Sudan that has been fermented with different starter levels [20, 50, 75 and 100 g of fermented baobab fruit pulp flour (FBFPF)/100 g flour]. Chemical composition, antinutritional factors, mineral extractability, ascorbic acid, in vitro protein (IVPD) and starch digestibilities (IVSD) of Kisra were determined. Preparation of Kisra with the sorghum genotypes fermented with higher levels of FBFPF enhanced the protein, fiber, fat, ash, and minerals contents and their extractability (P ≤ 0.05). Maximum amino acids contents were found in Kisra prepared from Tabat sorghum flour fermented with 100 g FBFPF/100 g flour. Ascorbic acid, IVPD and IVSD of Kisra from both genotypes increased with FBFPF levels, with a concomitant decrease in phytate and tannin contents (P ≤ 0.05). Sensory attributes of the Kisra were enhanced in Tabat and Wad-Ahmed sorghum genotypes prepared with 50 and 100 g FBFPF/100 g flour, respectively. Application of FBFPF is known to be an effective traditional starter, and it could improve the nutritional quality of Kisra bread.

Physicochemical, nutritional, functional, rheological, and microbiological properties of sorghum flour fermented with baobab fruit pulp flour as starter

Two sorghum genotypes termed Wad-Ahmed (high tannin) and Tabat (low tannin) in Sudan were fermented with different starter levels (0%, 25%, 50%, 75%, and 100%) of fermented baobab fruit pulp flour (FBFPF). Chemical composition, antinutrients, extracted minerals, and the microbiological, physicochemical, functional, rheological, and pasting properties from the fermented flours were determined. Fermentation of both genotypes with higher levels of FBFPF starter enhanced protein, fiber, ash, and major mineral contents and extractability (p ≤ 0.05). Total acidity, bulk density, rheological properties, in vitro protein, and starch digestibility of both genotypes increased with FBFPF levels, with a concomitant decrease in pH, phytate and tannin contents, and water and fat absorption capacities (p ≤ 0.05). Microbial loads, especially lactic acid bacteria, increased with increasing FBFPF starter levels in both genotypes. Use of FBFPF as a starter in the fermentation of sorghum flour can improve the nutritional value of sorghum. This could be usefully applied to the food industry for the development of fermented sorghum products.

Protective Effect of Adansonia digitata against Isoproterenol-Induced Myocardial Injury in Rats

The baobab fruit (Adansonia digitata) was analyzed for proximate composition, amino acids, and minerals. The fruit pulp was found to be a good source of carbohydrates, proteins, phenols, and substantial quantities of K, Ca, and Mg. Amino acid analyses revealed high glutamic and aspartic acid, but the sulfur amino acids were the most limited. The present study was designed to investigate the role of Adansonia digitata (Baobab fruit pulp) against isoproterenol induced myocardial oxidative stress in experimental rats by demonstrating the changes in tissue cardiac markers, some antioxidant enzymes, interleukin-1 β (IL-1 β), monocyte chemoattractant protein-1(MCP-1), myeloperoxidase (MPO), Collagen-1, galectin-3, and serum corticosterone. The activities of enzymatic antioxidant glutathione peroxidase (GPX) and non-enzymatic antioxidant reduced glutathione (GSH) in the heart tissue; additionally, histopathological examination of the heart was estimated. Male albino rats were randomly divided into four groups of ten animals each. Group I served as normal control animal. Group II animals received isoproterenol (ISP) (85 mg/kg body weight intraperitonealy (i.p.) to develop myocardial injury. Group III were myocardial oxidative animals treated with Baobab fruit pulp (200 µg/rats/day) for 4 weeks. Group IV received Baobab fruit pulp only. The data suggested an isoproterenol increase in levels of cardiac marker enzymes [creatine kinase MB (CK- MB), lactate dehydrogenase (LDH), and aspartate aminotransferase (AST)], IL-1ß, MCP-1, MPO, Collagen, and galectin-3, with concomitant decrease in the activities GPX and GSH in heart tissue as well as corticosterone in serum. Baobab fruit pulp brings all the parameters to near normal level in ISP-induced myocardial infarction in rats. Histopathological examination of heart tissue of ISP-administered model rat showed infiltration of inflammatory cells and congestion in the blood vessels. However, treatment with Baobab fruit pulp (200 µg/rats/day) showed predominantly normal myocardial structure and no inflammatory cell infiltration. It has been concluded that Baobab fruit pulp has cardio protective effect against ISP-induced oxidative stress in rats.