The objective of the study was to evaluate in vitro inhibitory effect of methanolic and methanolic-aqueous mixture extracts of Plectranthus neochilus Schltr (P. neochilus) and Bauhinia rufescens Lam (B. rufescens) on the growth of Escherichia coli 25922 and Proteus mirabilis. A phytochemical screening was carried out to highlight compounds (phenolic compounds, flavonoids, alkaloids) with antibacterial activity. Then, an antibiogram was Carried out to investigate the enzymes rendering the resistance. Finally, the E-test was used to evaluate the antibacterial activity of the extract mixture. The Screening results showed that both plants contain total phenolics, flavonoids and alkaloids compounds. The antibiogram has made it possible to establish the sensitivity profile of the strains tested with regard to certain antibiotics. The extract mixture showed antibacterial activity on both strains tested. In the present work, the different mixtures of extracts showed an inhibitory effect on Escherichia coli 25922 [a strain sensitive to almost all the antibiotics tested, in particular the three classes: beta-lactams (Ceftazidine, Ceftriaxone, Meropenem), quinolones (Levofloxacin, Ciprofloxacin) and aminoglycosides (Gentamicin, Amikacin)] and on Proteus mirabilis (a multiresistant strain with almost all the antibiotics tested).

“Kargasok” is an artisanal drink with a tangy, slightly sparkling flavour obtained by fermenting sweet tea (green or black tea). This drink is highly prized for its therapeutic properties and a means of subsistence to the producers but its production and quality is unknown. A study was then undertaken to highlight the manufacturing process and to characterise the quality of “Kargasok” tea. A field survey was conducted in three divisions of the Far north region (Diamaré, Mayo dany and Mayo kani). Fifty-four (54) samples of “Kargasok” were randomly sampled and the sensory, physicochemical, phytochemical and microbiological profiles were assessed using referenced methods. The production “Kargasok” is rudimentary with two main steps, decoction or infusion and aerobic fermentation. “Kargasok” tea had varying physicochemical properties, a total acidity of 5.76gL-1-6.11gL-1, a total sugar content ranging from 2.82 gL-1 to 3.14 gL-1, an average electrical conductivity of 669 µscm-1 and pH of 3.41. The tea is rich with bioactive components and was highly appreciation. Unfortunately, the hygienic quality is unsatisfactory. However, the panellists qualified the tea as orange-brown or brown in colour, tart and more fluid. “Kargasok” is a functional beverage whose production remains conventional and rudimentary despite the huge potentials.

No abstract

The purpose of this study was to evaluate the sensory property and shelf life of the processed mpedli beer using aqueous leaves extract of Vernonia amygdalina (VA) and heat treatment. The white sorghum beer was made at the laboratory scale using home-made procedure (Control). Following filtration, the beer was blended with an aqueous leaf extract (1/10, v/v) of VA (BUB). Pasteurization (60 °C/30 min) was performed on a portion of the VA blended sample (BPB). The sensory parameters and shelf life of the three samples were evaluated at room temperature during a month storage. The sensory characteristics of blended and non-supplemented mpedli beer differed significantly (p < 0.05). During storage, the colour, bitterness, aroma, odour, viscosity, texture, and overall acceptability of the processed samples were improved. Bitterness (r = 0.898; p < 0.01) and odour (r = 0.930; p < 0.01) were both highly correlated with the acceptance of the processed beer. The non-supplemented samples had the highest sensory scores 48 hours after preparation, while the relevant sensory ratings in processed BUB and BPB samples were recorded from the 12th to the 21st and 27th day of storage, respectively. The findings suggest that combining pasteurization with addition of aqueous leaf extract of VA may help smallscale brewers for improving the sensory quality and extending the shelf life of mpedli. According to the findings, the use of bitter leaf could be proposed as an alternative hop in the local brewing industry and may increase incomes of producers of local sorghum beer.

With the aim of ameliorating its preservation capacity, silver nanoparticles (0 -100 nm) with 99.9% purity and 35 nm average particle size, were used as building material for earthenware jar, an extremely old container which is still used in rural African villages specifically in North Cameroon. Earth material was dissolved in water at the weight ratio of 5% to 10%. Silver nanoparticles were then added to the mixture and stirred to prepare 1% to 5% Ag/Earth paste (1 to 5 ppm). A grounded metal rotating drum was used to prepare earth embedded nanosilver plates. An n-order mathematic expression was used to evaluate the shelf-live quality and deterioration rate of sorghum porridge preserved in this African earthenware container imbedded with nanosilver particles. Accelerated shelf-life testing was used to predict the shelf life of the product at usual rural storage conditions. The used Arrhenius model indicated that the shelf life of the sorghum porridge stored in African earthenware container imbedded with nanosilver particles can be extended to 14 days at 4˚C ± 1˚C, 6 days at 15˚C ± 5˚C, and 4 days at 30˚C ± 2˚C. The calculated Q10 values were found to be in the range of 1.5 -2.0.