COVID-19 preventives consumed in South Africa versus other Sub-Saharan African countries.

Background: The current coronavirus disease 2019 (COVID-19) pandemic has been of global concern as it has affected the health of many and the economies of nations. In order to strengthen the immune system against COVID-19, certain plant-source foods were consumed. Aim: This study was designed to identify and compare various special foods and drinks consumed to prevent COVID-19 during the lockdown in various sub-Saharan countries in comparison to South Africa (SA), as well as highlighting some current dietary recommendations. Setting: Online cross-sectional survey in six African countries, namely South Africa, Cameroon, Nigeria, Ghana, Ethiopia and Kenya. Methods: After sample size determination, an online questionnaire was designed and content validated. The survey link was pretested on 25 people and then circulated for 6 weeks during total lockdown. The proportion of responses for each question were reported using descriptive statistics. Results: Half of the 817 participants surveyed were not consuming anything special for COVID-19 prevention. South Africans mostly reported the consumption of supplements or conventional medicines (mainly vitamin C and zinc) while for other countries, a variety of natural foods and drinks were mentioned - some having already proved helpful in boosting immune systems. They included infusions of spices with or without honey, fruits and vegetables, medicinal drinks and local beverages. Conclusion: Programmes and campaigns designed to increase awareness of dietary measures for COVID-19 prevention have proved beneficial and should be promoted. Analytical evaluation of the nutritional and health benefits and antiviral potentials of the identified special foods would help in determining which foods to prioritise and promote in the fight against COVID-19. Contribution: This study shows the possibility of finding dietary solutions for managing the pandemic and 'preventive' potentials of certain plant substances.

Effect of the coronavirus pandemic on nutrition and health of adults in Calabar, Nigeria: A post-lockdown analysis.

Background: The food security and nutrition of millions of people around the world is currently being threatened by the coronavirus disease 2019 (COVID-19) pandemic, an evolving health crisis. Aim: To evaluate the effect of the COVID-19 pandemic on nutrition and health of adults in Calabar, especially after the hard lockdown. Setting: Online cross-sectional survey in Calabar, Nigeria. Method: After sample size determination, an online questionnaire was designed, content-validated by nutrition experts and piloted on 20 respondents. The questionnaire link was circulated for 6 weeks (April-May, 2021). The questionnaire was structured to gather socio-economic data, lifestyles of the participants (especially younger adults) and changes in dietary intake and health. Descriptive statistics and Pearson's correlation were used to define the proportion of responses for each question and check for association. Results: No glaring nutrition or health problems was observed in the surveyed population (385 respondents), but many (50%) earned very low monthly income (< 50 000 naira). A drop in finances seemed to have indirectly caused a decrease in food consumption post-lockdown. A strong association between age and health risks was observed; similarly, alcohol intake was significantly affected by income and age. Conclusion: The pandemic caused many changes in people's dietary habits and lifestyles, including financial setbacks. Apparently, education and proper enlightenment play a major role in food choices (despite limited resources), thus ensuring adequate nutrition and reducing health risks in the face of a pandemic. Contribution: This study has affirmed the efficacy of nutrition education and proper awareness in ensuring healthy dietary choices, optimal health and reduced risks of diseases.

Occurrence of Total Aflatoxins, Aflatoxin B1, and Ochratoxin A in Chicken and Eggs in Some Cameroon Urban Areas and Population Dietary Exposure.

Consumption of chicken and eggs contaminated by mycotoxins could lead to a public health concern. This study was conducted to evaluate the dietary exposure of populations to aflatoxins (AFs) and ochratoxin A (OTA) through these poultry products in the three most urbanized regions of Cameroon (Centre, Littoral, and West). A survey was firstly carried out to know about the consumption frequency by the different population age groups as well as their awareness about mycotoxins. Chicken feed, broiler, and eggs were collected from modern poultry farms. AFs and OTA were analysed using the enzyme-linked immunosorbent assay (ELISA), and dietary exposure was evaluated using a deterministic approach. From the 900 households questioned, a daily consumption frequency of chicken and eggs was the most reported (41% and 69%, respectively), with populations having a very weak knowledge of mycotoxins and their associated health risk (18%). Mean concentrations of AFs, AFB1, and OTA in poultry tissues were below the established regulated limits (20 µg/kg for AFs, 10 µg/kg for AFB1, and 5 µg/kg for OTA) in feeds. These toxins were detected at average concentrations of 1800 and 966.7 ƞg/kg for AFs in chicken muscle and egg, respectively, and 1400 and 1933.3 ƞg/kg for OTA in muscle and egg, respectively. Based on the survey, their estimated daily intakes through these poultry products tended to be lower than the limits 1 and 100 ƞg/kg bw/day for AFB1 and OTA, respectively). The margins of exposure (MOE) of the different population age groups to AFB1 and OTA obtained suggest that the public health concern associated with the presence of mycotoxins in poultry products shall not be underestimated.

Synergistic Action of Mild Heat and Essential Oil Treatments on Culturability and Viability of Escherichia coli ATCC 25922 Tested In Vitro and in Fruit Juice.

The strengthening effect of a mild temperature treatment on the antimicrobial efficacy of essential oils has been widely reported, often leading to an underestimation or a misinterpretation of the product's microbial status. In the present study, both a traditional culture-based method and Flow Cytometry (FCM) were applied to monitor the individual or combined effect of Origanum vulgare essential oil (OEO) and mild heat treatment on the culturability and viability of Escherichia coli in a conventional culture medium and in a fruit juice challenge test. The results obtained in the culture medium showed bacterial inactivation with an increasing treatment temperature (55 °C, 60 °C, 65 °C), highlighting an overestimation of the dead population using the culture-based method; in fact, when the FCM method was applied, the prevalence of injured bacterial cells in a viable but non-culturable (VBNC) state was observed. When commercial fruit juice with a pH of 3.8 and buffered at pH 7.0 was inoculated with E. coli ATCC 25922, a bactericidal action of OEO and a higher efficiency of the mild heat at 65 °C for 5' combined with OEO were found. Overall, the combination of mild heat and OEO treatment represents a promising antimicrobial alternative to improve the safety of fruit juice.

Development of a predictive model of the microbial inactivation of L. monocytogenes during low thermal treatment of fruit juices in combination with carvacrol as aroma compound.

Mild heat treatment of fruit juices in combination with natural aroma compounds has been reported as an alternative to conventional pasteurization to better preserve their nutritional value. However, its antimicrobial efficiency varies from one juice to another. This study aims at developing a secondary predictive model of microbial inactivation scale during such combined process. Carvacrol was used as aroma compound and acid-adapted L. monocytogenes as target microorganism. The inactivation kinetics of this bacteria were followed in simulated fruit juices using a Central Composite Design with pH (2-6), °Brix (0-24), temperature (55-65 °C), and carvacrol concentration (0-60 µL/L) as independent variables. Curves were fitted to the Weibull inactivation model, and data collected used to generate two predictive models of the inactivation scale parameter through multiple regression analysis following an empirical and a mechanistic (based on Gamma concept) approach. The best of the two models was then validated using real fruit (orange, pineapple, and watermelon) juices. The empirical model where only the four variables tested were considered showed a lower statistical performance compared to the mechanistic model where octanol-water partition coefficient (Ko/w) and vapour pressure (Vp) of carvacrol at the treatment temperature were integrated (R2 0.6 and 0.9; Accuracy factor 1.5 and 1.3; Sum of Squared Error 3.6 and 1.1, respectively). No significant difference was observed between inactivation scale values obtained with real juices and the predicted values calculated using this mechanistic model. The Ko/w and Vp of the aroma compound used are key parameters that determine the efficiency of the above-described combined treatment.

Effect of the coronavirus pandemic on nutrition and health of adults in Calabar, Nigeria: A post-lockdown analysis

Background: The food security and nutrition of millions of people around the world is currently being threatened by the coronavirus disease 2019 (COVID-19) pandemic, an evolving health crisis. Aim: To evaluate the effect of the COVID-19 pandemic on nutrition and health of adults in Calabar, especially after the hard lockdown.Setting: Online cross-sectional survey in Calabar, Nigeria. Method: After sample size determination, an online questionnaire was designed, content-validated by nutrition experts and piloted on 20 respondents. The questionnaire link was circulated for 6 weeks (April­May, 2021). The questionnaire was structured to gather socio-economic data, lifestyles of the participants (especially younger adults) and changes in dietary intake and health. Descriptive statistics and Pearson's correlation were used to define the proportion of responses for each question and check for association. Results: No glaring nutrition or health problems was observed in the surveyed population (385 respondents), but many (50%) earned very low monthly income (< 50 000 naira). A drop in finances seemed to have indirectly caused a decrease in food consumption post-lockdown. A strong association between age and health risks was observed; similarly, alcohol intake was significantly affected by income and age. Conclusion: The pandemic caused many changes in people's dietary habits and lifestyles, including financial setbacks. Apparently, education and proper enlightenment play a major role in food choices (despite limited resources), thus ensuring adequate nutrition and reducing health risks in the face of a pandemic. Contribution: This study has affirmed the efficacy of nutrition education and proper awareness in ensuring healthy dietary choices, optimal health and reduced risks of diseases.

COVID-19 preventives consumed in South Africa versus other Sub-Saharan African countries

Background: The current coronavirus disease 2019 (COVID-19) pandemic has been of global concern as it has affected the health of many and the economies of nations. In order to strengthen the immune system against COVID-19, certain plant-source foods were consumed. Aim: This study was designed to identify and compare various special foods and drinks consumed to prevent COVID-19 during the lockdown in various sub-Saharan countries in comparison to South Africa (SA), as well as highlighting some current dietary recommendations. Setting: Online cross-sectional survey in six African countries, namely South Africa, Cameroon, Nigeria, Ghana, Ethiopia and Kenya. Methods: After sample size determination, an online questionnaire was designed and content validated. The survey link was pretested on 25 people and then circulated for 6 weeks during total lockdown. The proportion of responses for each question were reported using descriptive statistics. Results: Half of the 817 participants surveyed were not consuming anything special for COVID-19 prevention. South Africans mostly reported the consumption of supplements or conventional medicines (mainly vitamin C and zinc) while for other countries, a variety of natural foods and drinks were mentioned ­ some having already proved helpful in boosting immune systems. They included infusions of spices with or without honey, fruits and vegetables, medicinal drinks and local beverages. Conclusion: Programmes and campaigns designed to increase awareness of dietary measures for COVID-19 prevention have proved beneficial and should be promoted. Analytical evaluation of the nutritional and health benefits and antiviral potentials of the identified special foods would help in determining which foods to prioritise and promote in the fight against COVID-19. Contribution: This study shows the possibility of finding dietary solutions for managing the pandemic and 'preventive' potentials of certain plant substances.

Evaluation of sanitary risks associated with the consumption of street food in the city of Yaoundé (Cameroon): case of braised fish from Mvog-Ada, Ngoa Ekélé, Simbock, Ahala and Olézoa.

An investigation was performed to evaluate the braising fish practices and the level of hygiene of the sellers in the city of Yaoundé. Thereafter, five braised carp samples were collected from each of the five selected sites and their microbiological quality assessed. The results showed that all the braising sites do not satisfy the Good Hygiene and Manufacturing Practices. Pathogenic microorganisms such as coliforms (2.17 ± 0.08 to 5.94 ± 0.38 Log cfu/g), E. coli (3.71 ± 0.20 to 6.21 ± 0.48 Log cfu/g) and Salmonella spp. were found in braised carp samples at levels higher than the microbiological criteria of the European Commission which are 1, 1 and 0 Log cfu/g, respectively. Spoilage microorganisms such as yeasts (2.39 ± 0.18 to 3.09 ± 0.23 Log cfu/g) and moulds (2.30 ± 0.10 to 2.92 ± 0.18 Log cfu/g) as well as spore-forming (3.02 ± 0.18 to 4.86 ± 0.35 Log cfu/g) and anaerobic (3.74 ± 0.28 to 4.52 ± 0.38 Log cfu/g) bacteria were also found at higher levels. The study highlights the poor microbiological quality of braised fish sold in the city of Yaoundé.

In vitro antimicrobial activity of Millettia laurentii De Wild and Lophira alata Banks ex C. F. Gaertn on selected foodborne pathogens associated to gastroenteritis.

This study aimed at evaluating the antimicrobial potential of aqueous, ethanolic and methanolic extracts of two Cameroonian plants against selected foodborne pathogens. Bioactive compounds were extracted from Millettia laurentii De Wild seeds and Lophira alata Banks ex. C. F. Gaertn leaves using distilled water, ethanol and methanol as solvents. The extracts were tested against Escherichia coli O157, Bacillus cereus, Staphylococcus aureus, Pseudomonas aeruginosa, Proteus mirabilis, Moraxella morganii, Salmonella enteritidis, Klebsiella pneumoniae and Listeria monocytogenes using the microdilution method. The results showed that distilled water extracted a more important mass of phytochemical compounds (18.0-24.60%) compared to ethanol (4.80-5.0%) and methanol (4.20-4.60%). All the extracts exhibited significant antimicrobial activity with MIC values ranging from 5 to 20 µg/mL for M. laurentii seeds extracts and from 1.0 to 20 µg/mL for L. alata leaves extracts. The different plant extracts were ten times less active than gentamicin. The most active extracts were obtained using ethanol as solvent and K. pneumoniae was the most resistant pathogen to all extracts (MBC>20 µg/mL). M. laurentii extracts were bactericidal against L. monocytogenes and P. mirabilis while the reference antibiotic (gentamicin) was bacteriostatic against these pathogens. The results obtained from this study suggest the studied local plant materials as a source of antimicrobial compounds which can be valorized in the medical field as substitute of antibiotics for which many microorganisms have nowadays developed resistance mechanisms. Further studies need to be performed in order to characterize and identify these antimicrobial active molecules.

Effect of low thermal pasteurization in combination with carvacrol on color, antioxidant capacity, phenolic and vitamin C contents of fruit juices.

Mild thermal treatment in combination with natural antimicrobials has been described as an alternative to conventional pasteurization to ensure fruit juices safety. However, to the best of our knowledge, no study has been undertaken to evaluate what could be its effect on their color and nutritional value. This study therefore aimed at assessing how a low thermal pasteurization in combination with carvacrol could affect these parameters, with orange, pineapple, and watermelon juices as selected fruit juices. The experimental design used had levels ranging from 50 to 90°C, 0 to 60 µl/L, and 0 to 40 min for temperature, concentration of carvacrol supplemented, and treatment length, respectively. The only supplementation of fruit juices with carvacrol did not affect their color. In comparison with high thermal pasteurization (>70°C), a combined treatment at mild temperatures (50-70°C) better preserved their color, antioxidant capacity (AOC), and vitamin C content, and increased their total phenolic content (TPC). Globally, carvacrol supplementation had a positive impact on the TPC of thermally treated juices and increased the AOC of treated watermelon juice, which was the lowest of the three fruit juices. Mild heat treatment in combination with natural antimicrobials like carvacrol is therefore an alternative to limit the negative effects of conventional pasteurization on fruit juices quality.