In Cameroon, alcoholic beverages remain the main consumed drink. In the Northern regions, indigenous sorghum beers are popular and widely consumed in an actively fermenting state by the people. In this study, some physicochemical parameters of the alcoholic sorghum beverages and correlations between them were evaluated during fermentation for 10 days. The indigenous white and red beers were produced at the laboratory scale assisted by experimented producers and some parameters (pH, total acidity, alcohol, sugars, density, total solids, temperature, and conductivity) were measured on the wort and fermented beverages. The pH decreases from 3.2 to 2.4 and 3.11 to 2.41; total acidity increases from 1.07 to 5.1 g/l and 0.5 to 4.6 g/l; alcohol enhances from 0 to 9.5% and 0 to 6.8% (v/v); total solids drop from 13.6 to 5°P and 12.2 to 3.3°P were observed respectively in the white and red sorghum beers. The multivariate analysis showed a good correlation between consumption of sugar, the decrease of total solids and density with the decrease in pH. It was also shown that, a perfect link exist between the production of alcohol and organic acids. The hierarchical analysis showed that indigenous red beer samples fermented for 1 and 2 days and those fermented for 4 to 10 days are related and could be separate in two distinct groups, whereas white turbid beer samples are separated in three different groups, those fermented for 1 to 4 days, those 5 to 6 days and those 7 to 10 days. The results obtained could serve as a guide to better understand the fermentation process of the indigenous alcoholic sorghum-based beverages.

Indigenous beers are very popular and widely consumed by people from northern Cameroon because of its low cost. Despite their appeal, microbial quality of these beverages remains a serious call for concern. This work was aimed to investigate microbial changes and hazards of contamination during the processing of two special sorghum beers brewed in northern Cameroon. Producers were observed during the production and samples were collected at different stages for analysis of microbiological parameters such as total count, fungi, spore-forming bacteria, Coliforms and E. coli using referenced methods. Total count ranged from 13.5 x 103 to 195 x 103 CFU/mL and 0.16 x 103 to 660 x 103 CFU/mL; fungi from 0.26 x 103 to 22 x 103 CFU/mL and 0.22 x 103 to 85 x 103 CFU/mL; E. coli from 0.69 x 102 to 13.6 x 102 CFU/mL and 0.65 x 102 to 3.8 x 102 CFU/mL during the production of the red “té” and white “mepdli” beers, respectively. Spore-forming bacteria and Coliforms (total and fecal) were detected in all the collected samples. Bacterial spores were also enumerated in red (38 x 103 CFU/g) and white (62.5 x 103 CFU/g) sorghum grains used as the main raw materials for the production of “té” and “mpedli” beers. The results suggest that the processing of both turbid beers using the traditional method are exposed to microbial contamination. Increase of microbial loads after soaking, adding of the supernatant (red beer only) and malted flour (white beer only) after the heating step means that control measures are needed to prevent contamination after these sensitive stages. Proper handling of raw materials, adequate implementation of heating and fermentation were found as effective critical control points. Training of producers on the hazards analysis and good manufacturing and hygiene practices have been suggested as strategies to improve the safety of indigenous beers.

“Téa Lémi” is a traditional wine made from pummelos by the Kapsiki in the Far-North of Cameroon. Despite its importance as a source of income for the country people, the know-how supporting production of this beverage and its quality attributes still remain unknown. Hence, this study was aimed at describing the processing and quality of “Téa Lémi” produced and marketed in northern Cameroon. The field investigation and the ethnographical technique were used to describe the production process. Physicochemical, phytochemical, and microbiological properties of the beverage were examined using referenced techniques. Quantitative descriptive analysis was used for describing the sensory profile of the wine. Surveys showed that processing of the grapefruit wine is typically artisanal. This can be seen by the uncontrolled addition of some ingredients such as sugar, extract of banana, and honey and a significant fermentation step started by wild, unselected yeasts. The physicochemical analyses revealed that the wine had an acid pH of around 3.84, with a total acidity between 7.72 g/L and 8.79 g/L. The alcohol and soluble solids contents were 14% (v/v) and 12 °Brix, respectively. Total sugar and conductivity values ranged from 57.8 to 96.8 g/L and 573 to 686 μS/cm. Mean contents of polyphenols and flavonoids of 616.4 mg PE/L and 322.5 mg QE/L and an antioxidant capacity of 261.03 mg TE/L have been revealed in the indigenous wine, respectively. The assessment of hygienic quality showed alarming sign of microbiological contamination revealed by total aerobic bacteria and spore-forming bacteria counts beyond the critical level. The good sensory quality (13 out of 20) of the grapefruit wine seemed to be linked to the sweetness (r = 0.999; p < 0.001 ) and odor/flavor (r = 0.997; p < 0.001 ). The beverage has been described by the panel as pale yellow colored, slightly tart, and bitter accompanied by some fruity esters and sweet notes of citrus and caramelized sugar.

Aims: “Foléré” beverage is a refreshing locally made drink much appreciated by the populations of the hottest parts of Cameroon. This paper aims at investigating microbial contamination of “Foléré” beverage and highlights impact of the sublethal temperatures on the hygienic quality the beverage. Study Design: Design used for describing physicochemical and microbial profile is a random sampling and for impact of sublethal temperature on hygienic quality, we used food matrix simulations. Place and Duration of Study: Samples: Local markets, between August 2018 and June 2019. Methodology: The sample pH and soluble solids content were recorded using portables devices. Microbial analysis focused on total aerobic mesophilic bacteria, Escherichia coli, and spore-forming bacteria were determined according to accredited culture methods. Acidic “Foléré” beverage produced by an artisanal processing was sterilized and inoculated by Bacillus cereus T spores and Escherichia coli ATCC 25922 cells thermally stressed by pre-incubation at 10°C, 45°C, 50°C or 60°C for 45 min, 90 min and 180 min. The recovery method was used to determine acid pH resistance of both bacteria before and after sublethal thermal processing. Results: “Foléré” beverage is of poor hygienic quality according to standards, despite its very low pH (2.01). Beverages at pH 2.01 and inoculated by each one of referenced bacteria indicated that the samples which contained thermally stressed bacteria were worse hygienic quality than the same ones which contaminated with unstressed bacteria. Some of recovery percentages of bacteria thermally stressed were significantly higher (P =.05) than those of same bacteria thermally unstressed after acid treatments. That phenomenon was called thermal-induced bacterial acid resistance. Conclusion: it appeared that some sublethal cold and heat shock treatments (10°C/45 min, 45°C/45 min, 50°C/90 min and 180 min) could negatively affect food quality. So, the control of emergence and evolution of stress-resistant bacteria in food could help to improve food safety.

A study on Cameroonian edible and medicinal plants was undertaken to assess their potential as food preservatives and natural food colorants. The ultrasound-assisted technique was used for the extraction of bioactive compounds. A total of 16 extracts prepared from 7 plants  (Aframomum melegueta S., Ageratum conyzoides L., Cympobogon citratus Stapf, Garcinia kola Heckel, Lantana camara L., Nauclea diderrichii, Vernonia amygdalina) were assayed to detect phytochemicals and assess antioxidant potential using the scavenging DPPH radical method and antimicrobial activity (10 mg/mL) against ten microorganisms by the agar well diffusion method. The ethanolic extract from L. camara leaves revealed the highest polyphenols and flavonoids contents. In contrast, the hexane/acetone extract from A. conyzoides and L. camara leaves had the highest chlorophyll a (Chl a) and chlorophyll b (Chl b) contents, whereas the highest carotenoid content was found in L. camara leaves. The ethanol extracts exhibited more significant antioxidant activity than hexane/acetone extracts. All seven plants (100%) inhibited the growth of at least one tested foodborne and spoilage bacteria and fungi. The germination of both Bacillus spp. spores were also affected. The hexane/acetone extracts were by far the best antimicrobial agent, and extract from L. camara leaves was one of the most effective, with a large antimicrobial spectrum. The antimicrobial activity of extracts was correlated to the amount of carotenoids and chlorophylls. HPLC-DAD revealed bioactive compounds as chlorogenic and caffeic acids found as major phenols in ethanolic extract of L. camara leaves, whereas lutein, carotene, and zeaxanthin were the specific carotenoids present in hexane/acetone extract of the same plant.

The objective of this study was to determine the phytochemical profile and antimicrobial activity of leaf and bark extracts of Ziziphus mauritiana and Ziziphus mucronata. For this purpose, an extraction by maceration using ethanol was carried out and the extracts were subjected to antibacterial activity assessment through qualitative and quantitative approaches. The qualitative tests were performed using agar well diffusion method while for quantitative tests minimal inhibitory, bactericidal and fungicidal concentration (MIC, MBC or MFC) were used determined through microdilution in microplates method. The antimicrobial mechanisms such as cell lysis and action on the proton pump of the extracts were also studied. The highest extraction yield was obtained with the Z. mauritiana leaf extract (28.8%). In addition, the highest contents of polyphenols (256.6 mg GEA/g DM) and flavonoids (165.2 mg CE/g DM) were obtained with the bark of Z. mucronata. The bark extracts of Z. mauritiana exhibited highest antibacterial activity (36.7 mm on Staphylococcus aureus) while, Z. mucronata extracts are more active on fungi, with the highest activity on Candida albicans (26.7 mm). The antimicrobial activity of the extract increases with the concentration and, regarding the MBC/MIC and MFC/MIC ratio, the extracts showed bacteriostatic activity on the different bacteria and fungi and the possible mechanism included an activity on the proton pump. The bark and leaf extracts of Z. mauritiana and Z. mucronata could be used in traditional medicine to treat infections due to these multiple pathogens.

In Cameroon, alcoholic beverages represent one of the main consumed drinks. In northern regions, indigenous sorghum beers are very popular and widely consumed in an actively fermenting state by people. In this study, some physicochemical parameters of alcoholic sorghum beverages and correlations between them were evaluated during fermentation for 10 days. The indigenous white and red beers were produced at the laboratory scale assisted by experimental producers and some parameters (pH, total acidity, alcohol, sugars, density, total solids, temperature, and conductivity) were measured on the wort and fermented beverages. The pH decreased from 3.2 to 2.4 and 3.11 to 2.41; total acidity increased from 1.07 to 5.1 g/L and 0.5 to 4.6 g/L; alcohol was enhanced from 0 to 9.5% and 0 to 6.8% (v/v); total solids dropped from 13.6 to 5°P and 12.2 to 3.3°P, respectively, in the white and red sorghum beers. The multivariate analysis showed a good correlation between consumption of sugar, the decrease in total solids and density with the decrease in pH. Additionally, it was shown that a perfect link exists between the production of alcohol and organic acids. The hierarchical analysis showed that indigenous red beer samples fermented for one and two days and those fermented for four to 10 days were related and could be separate in two distinct groups, whereas white turbid beer samples were separated in three different groups, those fermented for one to four days, five to six days, and seven to 10 days. The results obtained could serve as a guide to better understand the fermentation process of indigenous alcoholic sorghum-based beverages.

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