Acetobacter senegalensis isolated from mango fruits: Its polyphasic characterization and adaptation to protect against stressors in the industrial production of vinegar: A review.

It has been more than a decade since Acetobacter senegalensis was isolated, identified and described as a thermotolerant strain of acetic acid bacteria. It was isolated from mango fruits in Senegal and used for industrial vinegar production in developing countries, mainly in sub-Saharan Africa. The strain was tested during several spirit vinegar fermentation processes at relatively high temperatures in accordance with African acclimation. The upstream fermentation process had significant stress factors, which are highlighted in this review so that the fermentation process can be better controlled. Due to its high industrial potential, this strain was extensively investigated by diverse industrial microbiologists worldwide; they concentrated on its microbiological, physiological and genomic features. A research group based in Belgium proposed an important project for the investigation of the whole-genome sequence of A. senegalensis. It would use a 454-pyrosequencing technique to determine and corroborate features that could give this strain significant diverse bio-industrial applications. For instance, its application in cocoa bean fermentation has made it a more suitable acetic acid bacterium for the making of chocolate than Acetobacter pasteurianus. Therefore, in this paper, we present a review that summarizes the current research on A. senegalensis at its microbial and genomic levels and also its specific bio-industrial applications, which can provide economic opportunities for African agribusiness. This review summarizes the physiological and genomic characteristics of Acetobacter senegalensis, a thermotolerant strain isolated from mango fruits and intended to be used in industrial vinegar fermentation processes. It also explores other bio-industrial applications such as cocoa fermentation. Vinegar fermentation is usually performed with mesophilic strains in temperate regions of the world. Developing countries, such as Senegal, import vinegar or make 'fake' vinegar by diluting acetic acid obtained from petrochemicals. The use of a thermotolerant Acetobacter senegalensis strain as a solid functional starter culture, as well as the design of a new adapted bioreactor, has significantly contributed to food security and the creation of small- to medium-sized enterprises that produce mango vinegar in West Africa.

Assessing the Quality of Burkina Faso Soybeans Based on Fatty Acid Composition and Pesticide Residue Contamination.

Soybean is widely used in the food industry because of its high fatty acid and protein content. However, the increased use of pesticides to control pests during cultivation, in addition to being a public health concern, may influence the nutritional quality of soybeans. This study aimed to assess the nutritional quality of soybeans with respect to fatty acid profile and pesticide residue contamination. The levels of fatty acids and pesticides in soybean varieties G196 and G197 were determined by gas chromatography and by the QuEChERS method, respectively. The results showed a significant variation in the quantitative and qualitative fatty acid composition of the two varieties, with 18.03 g/100 g and 4 fatty acids detected for the G196 variety and 21.35 g/100 g and 7 fatty acids for the G197 variety, respectively. In addition, 12 active pesticide compounds were found, and among them, imazalil, quintozene, cyfluthrin and lindane exceeded their maximum limits. The G197 variety had a better nutritional profile compared to G196. The profile of fatty acids and the content of pesticide residues were used as important determinants for soybean utilization in human nutrition.

Characteristics, composition and oxidative stability of Lannea microcarpa seed and seed oil.

The proximate composition of seeds and main physicochemical properties and thermal stability of oil extracted from Lannea microcarpa seeds were evaluated. The percentage composition of the seeds was: ash (3.11%), crude oil (64.90%), protein (21.14%), total carbohydrate (10.85%) and moisture (3.24%). Physicochemical properties of the oil were: refractive index, 1.473; melting point, 22.60°C; saponification value, 194.23 mg of KOH/g of oil; iodine value, 61.33 g of I2/100 g of oil; acid value, 1.21 mg of KOH/g of oil; peroxide value, 1.48 meq of O2/kg of oil and oxidative stability index, 43.20 h. Oleic (43.45%), palmitic (34.45%), linoleic (11.20%) and stearic (8.35%) acids were the most dominant fatty acids. Triacylglycerols with equivalent carbon number (ECN) 48 and ECN 46 were dominant (46.96% and 37.31%, respectively). The major triacylglycerol constituents were palmitoyl diolein (POO) (21.23%), followed by dipalmitoyl olein (POP) (16.47%), palmitoyl linoleyl olein (PLO) (12.03%), dipalmitoyl linolein (PLP) (10.85%) and dioleoyl linolein (LOO) (9.30%). The total polyphenol and tocopherol contents were 1.39 mg GAE g-1 DW and 578.56 ppm, respectively. γ-Tocopherol was the major tocopherol (437.23 ppm). These analytical results indicated that the L. microcarpa seed oil could be used as a frying oil and in the cosmetic industry.

In Vivo Diuretic Activity and Anti-Hypertensive Potential of Hibiscus sabdariffa Extract by Inhibition of Angiotensin-Converting Enzyme and Hypertension Precursor Enzymes.

Aqueous extracts of calyx from Hibiscus sabdariffa (HS) (roselle) are highly appreciated for their nutritional and therapeutic effects, especially as anti-hypertensive substances. This study aimed to evaluate their anti-hypertensive potential through an in vitro inhibition assay of angiotensin-converting enzyme (ACE) and hypertension precursor enzymes and to assess the in vivo diuretic activity of HS. Results showed that HS extract inhibited enzymes belonging to several classes, such as α-amylase, trypsin, chymotrypsin, xanthine oxidase, lipoxygenase, and angiotensin-converting enzyme. In particular, enzymatic kinetics of ACE indicated a competitive inhibition fashion of HS extract. Furthermore, the extracts showed remarkable diuretic and natriuretic effects at doses of 50 mg/kg/bw, 100 mg/kg/b.w, and 200 mg/kg.b.w. These activities can be explained by the high content of phenolic compounds and essential amino acids. Roselle could be a potential source of nutraceuticals and anti-hypertensive bioactive compounds.

Reduction of Malnutrition Related to Unsafe Water Consumption in Developing Countries: Potabilization of Surface Water and Traditional Well Water, with Plant Extracts.

The consumption of unsafe water in rural areas is a real public health problem in developing countries. This situation mainly affects children under five years of age and causes several deaths and many cases of malnutrition every year. The objective of this study was to evaluate and optimize the capacity of four local plant extracts in the potabilization of unsafe water. Thus, Moringa oleifera and Boscia senegalensis seeds, or Aloe vera and Opuntia ficus-indica mucilages were prepared in a solution and applied during a jar test as biocoagulants and bioflocculants on three raw water samples of 82.3 NTU, 549.8 NTU and 796.9 NTU. After treatment results showed that 0.9 g/L of Moringa biocoagulant or 1 g/L of Boscia biocoagulant applied with 0.4 mL of Aloe vera bioflocculant or 0.6 mL of Opuntia ficus-indica bioflocculant reduced the turbidity of each water sample to values less than 5 NTU after only 15 min of decanting. Moreover, the sanitary quality of the water treated by these different extracts showed a perfect conformity of the physicochemical and microbiological parameters with the standards of acceptability in drinking water decreed by the World Health Organization. Thus, the application of these local plant extracts has made it possible to considerably improve the quality of unsafe water in record time. Their popularization could be an alternative in the fight against malnutrition related to the consumption of unsafe water, especially in rural areas.

Modelling and optimisation of ultrasound-assisted extraction of roselle phenolic compounds using the surface response method.

Extracts from Hibiscus sabdariffa L. (roselle) have been used traditionally as a food, in herbal medicine, in hot and cold beverages, as flavouring or coloring agent in the food industry. In vitro and in vivo studies and trials provide evidence, but roselle is poorly characterised phytochemically due to the extraction processes. The optimization of the extraction of phenolic compounds and their antioxidant activities is still a hot topic. In this study, the effect of solute/solvent ratio (33, 40 and 50 mg/mL), extraction temperature (40, 50 and 60 °C) and extraction time (30, 60 and 90 min) was evaluated through the content of phenolic compounds and antioxidant activity. A response surface methodology through a Box-Behnken design was applied and model fit, regression equations, analysis of variance and 3D response curve were developed. The results showed that TPC, TFC, DPPH and FRAP were significantly influenced by temperature, extraction time and solvent/solute ratio. Thus, TPC, TFC, DPPH and FRAP varied from 5.25 to 10.58 g GAE/100 g DW; 0.28 to 0.81 g QE/100 g DW; 0.24 to 0.70 mg/mL; 2.4 to 6.55 g AAE/100 g DW respectively. The optimal experimental condition (41.81 mg/mL; 52.35 °C and 57.77 min) showed a significant positive effect compared to conventional methods. The experimental values at this extraction condition show that this optimization model is technologically, financially and energetically viable as it requires a reasonable concentration, time and temperature.

Correction: Hibiscus sabdariffa: Genetic variability, seasonality and their impact on nutritional and antioxidant properties.

[This corrects the article DOI: 10.1371/journal.pone.0261924.].

An X-linked haplotype of Neandertal origin is present among all non-African populations.

Recent work on the Neandertal genome has raised the possibility of admixture between Neandertals and the expanding population of Homo sapiens who left Africa between 80 and 50 Kya (thousand years ago) to colonize the rest of the world. Here, we provide evidence of a notable presence (9% overall) of a Neandertal-derived X chromosome segment among all contemporary human populations outside Africa. Our analysis of 6,092 X-chromosomes from all inhabited continents supports earlier contentions that a mosaic of lineages of different time depths and different geographic provenance could have contributed to the genetic constitution of modern humans. It indicates a very early admixture between expanding African migrants and Neandertals prior to or very early on the route of the out-of-Africa expansion that led to the successful colonization of the planet.

Hibiscus sabdariffa: Genetic variability, seasonality and their impact on nutritional and antioxidant properties.

This study consisted of the physicochemical, phytochemical and antioxidant characterisation of two varieties of Hibiscus sabdariffa, to evaluate the influence of genetic and environmental factors on these parameters leading to an objective and rigorous classification of our extracts. To this end, calyxes and seeds of the red and white phenotypes were collected in Bobo-Dioulasso, Dano and Nouna respectively in December 2019 and 2020. Principal component analysis showed that physico-chemical and biochemical parameters could potentially be used to discriminate varieties. The calyxes of the sabdariffa variety showed the best physicochemical profile (total phenolics, flavonoids, ascorbic acid), pigments (anthocyanins, chlorophyll) and antioxidant activity (free radical scavenging and SOD activity) while the seeds showed the best carbohydrate, lipid and peroxidation inhibition content. In view of these results, the red phenotype has an interesting nutritional and therapeutic potential. It could therefore be interesting candidate in the pharmaceutical and food industries.

Toxicological profile, phytochemical analysis and anti-inflammatory properties of leaves of Vitex doniana Sweet. (Verbenaceae).

Background: Natural herbal compounds are a source and alternative for new compounds with anti-inflammatory properties. Therefore, in-depth studies should be carried out to assess their safety and efficacy in order to avoid or prevent toxicological risks of these natural plant-based substances. V. doniana is a species of food plant used for the treatment of inflammatory diseases in Burkina Faso. This study aimed to estimate the anti-inflammatory properties in vitro and in vivo of the ethyl acetate fraction of the leaves of V. doniana. Methods: To do this, acute toxicity was first evaluated on the animal model. Biological activities (carrageenan test, formalin and xylene induced oedemas) were used to assess the anti-inflammatory power. Results: Regarding the dietary toxicology of the extracts, visual and clinical signs showed that the extracts are not at the end of the 15-day (acute toxicity) and 45-day (subacute toxicity) tests. In terms of anti-inflammatory activity in vivo, it was observed that the bioactive fraction (50, 100 and 200 mg/kg.b.w) had effective neurogenic anti-inflammatory properties. All of these effects observed were all dose-dependent. Conclusion: The results of this present research have proven that V. donania extracts can be used as anti-inflammatories.

Tomato By-Products, a Source of Nutrients for the Prevention and Reduction of Malnutrition.

Malnutrition is a global phenomenon that mainly affects children under five years old, the elderly and food insecure people. It can be linked to undernourishment or overnutrition. To prevent it, a healthy and balanced diet, rich in energy and micronutrients, is necessary. The objective of this study was to evaluate the nutritional composition and contribution of tomato by-products to prevent and reduce malnutrition. Thus, standard methods were used for proximate composition and bioactive compounds. Results showed that tomato by-products are rich in macronutrients and micronutrients capable of preventing undernutrition and reducing the incidence of the effects of overnutrition. The average carbohydrate, protein and lipid contents were 15.43%, 11.71% and 5.4% (DM) in peels and for seeds the contents were 58.75%, 15.4% and 22.2%, respectively. The average energy values were 280.47 kcal/100 g and 472.8 kcal/100 g DM for peels and seeds, respectively. The main minerals found were, in decreasing order, potassium, magnesium, sodium, iron and zinc. High contents of phenolic compounds, lycopene, ß-carotene and vitamin C were also found in these by-products. They also presented important antioxidant activities. Due to their nutritional and bioactive compounds, tomato by-products may be included in functional food formulation programs to reduce the incidence of nutritional diseases.

Evaluation of the physicochemical parameters of edible oils sold in the three cities of Burkina Faso.

The edible oil needs of African countries are met by imported or locally produced ones. Therefore, consumers are generally confronted with a choice of edible oils of poorly controlled quality. However, quality control of edible oils for local consumption is of high necessity. This study aimed to assess the quality of edible oils sold and consumed in some cities in Burkina Faso. Oil samples collected in the cities of Dédougou, Koudougou, and Nouna were used for several analyses. Oil samples from palm, refined and unrefined cottonseed, and groundnut were collected. Standard methods were used to assess the physicochemical quality parameters of the oils, including the peroxide value, water and volatile matter content, acid value, traces of soap, and mineral oil contents. The parameters varied significantly depending on the oil type, but not by the locality of origin. The peroxide indices had varied from 3.24 to 39.99 mEq O2/kg oil. The acid indices varied from 0.22 mg KOH/g to 1.24 mg KOH/g. The water and volatile matter contents ranged from 0.04% to 0.88%. The test for traces of soap gave values ranging from 0 to 76 ppm. For the mineral oil test, four samples of cottonseed oil collected in Dedougou gave positive results. Compared to international reference standards, in particular the Codex Alimentarius standard, it may constitute a health risk for consumers. The poor storage, distribution, and marketing conditions of the oils could explain their poor quality. In order to provide consumers with quality oils, regular controls must be undertaken in the places where the oils are stored and/or marketed.

Correlating the morphology of Anacardium occidentale L. fruits from 30 orchards with their physicochemical and nutritional properties.

Cashew (Anacardium occidentale L.) is a cross-pollinating plant whose fruit consists of two parts, the nut, and the apple. This study aimed to carry out agro-morphological characteristics of cashew fruits to establish relationships with their physicochemical and nutritional properties. Thirty (30) cashew accessions fruits were sampled in different regions of Burkina Faso. The length, width, thickness, weight, yield, kernel output ratio (KOR), proximate composition, specific minerals, phenolic compounds, and anti-nutritional factors were assessed. Evaluations were made using standard methods. The results showed significant variations in agro-morphological, physicochemical and nutritional traits depending on the accessions and the organ. Also, the ratio of apple mass versus nut one was about 12.24 ± 1.24. Kernels are an important source of proteins, fat, total phenolic compounds, and flavonoids, with average contents of 22.84 ± 1.25 g/100 g, 51.65 ± 2.54 g/100 g, 9.78 ± 2.15 mg GAE/g, and 6.24 ± 12.15 mg QE/g, respectively. As for the apples, they contained substantial quantities of Potassium, Phosphorus, Chlorine, and Magnesium with contents of 611.24 ± 14.5 mg/100 g, 418.24 ± 16.47 mg/100 g, 332.24 ± 10.54 mg/100 g, and 224.95 ± 13.15 mg/100 g, respectively. Statistical analyses showed that mineral and phytate contents were positively correlated to cashew apples while phenolic compounds and tannins were strongly correlated with walnuts. Principal component analyses showed three groups of accessions based on apples and kernels characteristics. These data showed a direct relationship between cashew physicochemical, nutritional potentials, kernels, and apples' agro-morphological characteristics. These data constitute an important basis for the identification of cashew accessions with high nutritional and economic potential.

Comparison of Proximate and Phytonutrient Compositions of Cashew Nuts and Apples from Different Geographical Areas of Burkina Faso.

The cashew plant is an allogamous plant that produces two types of fruits: the nut and the cashew apple. The present study was conducted to perform a comparison of proximate and phytonutrient compositions of cashew (Anacardium occidentale L.) nuts and apples from different geographical areas of Burkina Faso. For this purpose, 60 samples of apples and kernels were collected from the three main cashew cultivation areas. The nutritional potential of cashew nuts and apples produced was evaluated to enhance their food processing. Protein, carbohydrates, lipids, dietary fibers, ascorbic acid, tannins, anthocyanins, chlorophyll, lycopene, and ß-carotene contents were assessed. The results revealed high contents of lipids (50.42 ± 2.3 g/100 gDW), proteins (22.32 + -1.8 g/100 gDW), and starch (12.05 ± 1.27 g/100 g DW) in almonds. Apples, on the other hand, are rich in lipids, ascorbic acid (387.45 ± 17.4 mg/100 g), soluble sugars (387.45 ± 17.4 mg/100 g,), and pigments (lycopene, anthocyanin, ß-carotene, and chlorophyll). In summary, almonds may be suitable as a source of lipids and related products. Apples can be used as natural antioxidants and produce juices. All of these data are important clues for cashew by-product processing. These results obtained provide a scientific basis for their food and economical valorization of cashew fruits.

Safety Profile, In Vitro Anti-Inflammatory Activity, and In Vivo Antiulcerogenic Potential of Root Barks from Annona senegalensis Pers. (Annonaceae).

Annona senegalensis (Annonaceae) is a tropical shrub widely distributed in Burkina Faso. This plant is traditionally used as a medicine against many pathologies including typhoid fever, gastrointestinal disorders, ulcers, and inflammatory and infectious diseases. The present study was conducted to evaluate the anti-inflammatory and antiulcer properties of Annona senegalensis root bark extracts. Therefore, toxicity tests were first performed, followed by other biological tests. For this purpose, we first undertook to evaluate the toxicity tests before considering the other biological tests in a second step. The results showed that the extracted fractions had a significant effect for the different methods used (protein denaturation inhibition activity, hyaluronidase inhibition activity, and xanthine oxidase inhibition activity). However, of the extracted fractions used, the ethyl acetate fraction was the most anti-inflammatory fraction. The antiulcer activity was evaluated using the best bioactive fraction. The antiulcer effect of the ethyl acetate fraction may be due to both the reduction of gastric acid secretion and gastric cytoprotection. The results of this study also showed that the bioactive fraction reduced ethanol-induced ulceration and pyloric ligation in a dose-dependent manner, and at the highest dose (200 mg/kg), the effect was similar to that of the reference drug. In summary, the ethyl acetate fraction was found to have the best anti-inflammatory and antiulcerogenic activities. The ethyl acetate fraction at a dose of 200 mg/kg also showed a rather interesting level of cytoprotection. The anti-inflammatory and antiulcer activities could be due to the different secondary metabolites contained in the fractions extracted from Annona senegalensis, notably flavonoids, triterpenoids, steroids, saponins, and tannins. As the mechanisms of action are still little or not understood, we will consider in the future identifying the phytoconstituents and the mechanisms of action involved in the results.

Composition and antimicrobial activities of Lippia multiflora Moldenke, Mentha x piperita L. and Ocimum basilicum L. essential oils and their major monoterpene alcohols alone and in combination.

Essential oils from leaves of Lippia multiflora, Mentha x piperita and Ocimum basilicum from Burkina Faso were analysed by GC-FID and GC-MS. Major components were p-cymene, thymol, b-caryophyllene, carvacrol and carvone for L. multiflora, menthol and iso-menthone for M. x piperita and, linalool and eugenol for O. basilicum. The essential oils and their major monoterpene alcohols were tested against nine bacterial strains using the disc diffusion and broth microdilution methods. The essential oils with high phenolic contents were the most effective antimicrobials. The checkerboard method was used to quantify the efficacy of paired combinations of essential oils and their major components. The best synergetic effects among essential oils and major components were obtained with combinations involving O. basilicum essential oil and eugenol, respectively. As phenolic components are characterized by a strong spicy aroma, this study suggests that the selection of certain combinations of EOs could help to reduce the amount of essential oils and consequently reduce any adverse sensory impact in food.

Inhibition of Bacillus cereus growth by bacteriocin producing Bacillus subtilis isolated from fermented baobab seeds (maari) is substrate dependent.

Maari is a spontaneously alkaline fermented food condiment made from baobab tree seeds. Due to the spontaneous nature of maari fermentations growth of the opportunistic human pathogen Bacillus cereus is occasionally observed. Bacillus subtilis strains are important for alkaline seed fermentations because of their enzymatic activities contributing to desirable texture, flavor and pH development. Some B. subtilis strains have antimicrobial properties against B. cereus. In the present work, three bacteriocin producing B. subtilis strains (B3, B122 and B222) isolated from maari were tested. The production of antimicrobial activity by the three strains was found to be greatly influenced by the substrate. All three B. subtilis strains produced antimicrobial activity against B. cereus NVH391-98 in BHI broth as determined by the agar well diffusion assay, whereas no antimicrobial activity was detected in whole cooked baobab seeds and in 10% (w/v) grinded baobab seeds. Incorporation of BHI with up to 5% (w/w) grinded baobab seeds enhanced the antimicrobial activity of B. subtilis compared with pure BHI in a strain dependent manner. Incorporation of BHI with 50% (w/w) baobab grinded seeds decreased the antimicrobial activity. Addition of the inorganic salts FeCl3, MgSO4 and MnSO4 has previously been reported to increase bacteriocin production of B. subtilis, but the addition of these salts to 10% (w/v) grinded baobab seed broth did not cause antimicrobial activity. Survival of B. cereus NVH391-98 in co-culture with B. subtilis was tested in BHI broth, 10% (w/v) grinded baobab seed based broth and during baobab seed fermentation to produce maari. B. cereus NVH391-98 grew well in all three substrates in mono-culture. All the 3 B. subtilis strains were able to decrease B. cereus NVH391-98 to levels below the detection limit (<10 CFU/ml) in BHI, but not in baobab seed based substrates, even though the outgrowth of B. cereus NVH391-98 was delayed by up to 40 h. In conclusion, production of antimicrobial activity by the investigated B. subtilis strains is highly substrate-specific and strain-specific. The three B. subtilis strains delayed but did not prevent B. cereus outgrowth during baobab seed fermentations. Maari is produced through mixed microbial population fermentations. B. subtilis co-starter culture candidates originating from maari which are able to prevent pathogen outgrowth remain to be identified.

Bacteriocin formation by dominant aerobic sporeformers isolated from traditional maari.

The antimicrobial activity of 8 Bacillus spp. and 2 Lysinibacillus spp. representing the predominant aerobic sporeformers during traditional maari fermentations, a traditional fermented baobab seeds product from Burkina Faso, was investigated. The antimicrobial activity was assessed against a total of 31 indicator organisms representing various Gram-negative and positive pathogens. The screening showed that 3 Bacillus subtilis strains (B3, B122 and B222) in particular had antimicrobial activity against some Gram-positive organisms and were selected for further studies. It was found that the antimicrobial substances produced were heat stable, in-sensitive to catalase, sensitive to protease and trypsin but resistant to the proteolytic action of papain and proteinase K and equally active at pH values ranging from 3 to 11. Bacteriocin secretion started in late exponential growth phase and maximum activity was detected during the stationary growth phase. The production of bacteriocin by B. subtilis B3, B122 and B222 was dependent on the aeration conditions. Maximum production of bacteriocin was observed under reduced aeration. Specific primers were used to screen isolates B3, B122 and B222 for genes involved in the synthesis of the bacteriocins subtilosin A, subtilin, sublancin and ericin. Amplicons of the expected sizes were detected for iywB, sboA, sboX, albA and spaS involved in the biosynthesis of subtilosin and subtilin, respectively. The translated nucleotide sequences had 100% identity to the YiwB, SboX and SboA amino acid sequences of the subtilosin A producing B. subtilis subsp. subtilis strain 168. Interestingly there was a 3 amino acid deletion at the N-terminal part of AlbA in B3, B122 and B222 that probably alters the activity of this enzyme. Analysis of the spaS gene sequences of B3, B122 and B222, encoding a subtilin precursor peptide, showed that the translated nucleotide sequence had 98% identity with the corresponding SpaS amino acid sequence of subtilin producing B. subtilis subsp. spizizenii strain ATCC6633.