Proximate composition, microbiological quality and presence of total aflatoxins and aflatoxin B1 in the flesh of three snails’ species (Achatina achatina, Achatina fulica and Archachatina marginata) from a selected locality of Yaoundé, Cameroon

The increasing need for animal proteins has led to an interest in non-conventional protein sources such as snails. Although several species of snails are locally reared and highly prized by Cameroonians, there is a lack of information regarding their composition and safety. This work aimed at assessing the chemical composition, the microbiological quality and the total aflatoxins (AFs) and aflatoxin B₁ (AFB₁) contents of the fleshes from three snails’ species traditionally reared in the city of Yaoundé, Cameroon. Samples of Achatina achatina (10), Achatina fulica (10) and Archachatina marginata (10) were randomly collected from a selected farm in Mimboman quarter of Yaoundé and their chemical composition and microbiological quality were evaluated through AOAC and ISO methods, respectively. Their levels of AFs and AFB₁ were assessed using competitive ELISA. The results showed that snail fleshes were a good source of proteins and iron with the one from A. achatina containing the highest protein (15.26%) and iron (7.80 mg/100g) contents. Microbiological analyses revealed that the total aerobic counts of the different samples of snail fleshes were all higher than 6 Log CFU/g thus suggesting a reduced shelf life of the raw product. The safety issue of the snail fleshes is questionable as they contained pathogens such as coliforms and Staphylococcus spp. at levels higher than the norms. Although yeasts and moulds were found in snail fleshes at loads ranging from 3.5 to 4.17 Log CFU/g, their AFs and AFB₁ contents were respectively below 0.22 and 0.44 ppb, values that are lower than that of raw food intended for human consumption. This study demonstrated the potential of snails as an alternative protein source from animal origin and suggests that particular attention should be paid by the government to sensitize the farmers on good hygiene and farming practices and the consumers on good cooking practices.

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.

Recovery rate of children with moderate acute malnutrition treated with ready-to-use supplementary food (RUSF) or improved corn-soya blend (CSB+): a randomized controlled trial

OBJECTIVE

To compare an improved corn-soya blend (CSB+) with a ready-to-use supplementary food (RUSF) to test the hypothesis that satisfactory recovery rate will be achieved with CSB+ or RUSF when these foods provide 50 % of the child's energy requirement, the 50 % remaining coming from usual diet.

DESIGN

A comparative efficacy trial study was conducted with moderately wasted children, using a controlled randomized design, with parallel assignment for RUSF or CSB+. Every child received a daily ration of 167 kJ (40 kcal)/kg body weight during 56 d with a follow-up performed every 14 d. Every caregiver received nutrition counselling at enrolment and at each follow-up visit.

SETTING

Health districts of Mvog-Beti and Evodoula in the Centre region of Cameroon.

SUBJECTS

Eight hundred and thirty-three children aged 6-59 months were screened and eighty-one malnourished children (weight-for-height Z-score between -3 and -2) aged 25-59 months were selected.

RESULTS

Of children treated with CSB+ and RUSF, 73 % (95 % CI 59 %, 87 %) and 85 % (95 % CI 73 %, 97 %), respectively, recovered from moderate acute malnutrition, with no significant difference between groups. The mean duration of treatment required to achieve recovery was 44 d in the RUSF group and 51 d in the CSB+ group (log-rank test, P=0·0048).

CONCLUSIONS

There was no significant difference in recovery rate between the groups. Both CSB+ and RUSF were relatively successful for the treatment of moderate acute malnutrition in children. Despite the relatively low ration size provided, the recovery rates observed for both groups were comparable to or higher than those reported in previous studies, a probable effect of nutrition education.

Validity of anthropometry- and impedance-based equations for the prediction of total body water as measured by deuterium dilution in Cameroonian haemodialysis patients

BACKGROUND & AIMS

There is no available information on the validity of anthropometry- and impedance-based equations for predicting total body water (TBW) in Cameroonian haemodialysis patients. This study aimed to validate and develop predictive equations of TBW for Cameroonian haemodialysis patients.

METHOD

TBW in 40 Cameroonian haemodialysis patients (28 men and 12 women) was measured by deuterium dilution and compared with the one predicted by 7 anthropometric and 9 BIA equations. Multiple linear regression analysis was used to develop an equation for predicting TBW as measured by deuterium, from anthropometric parameters.

RESULTS

Pure errors in predicting TBW showed unacceptable value for all equations tested. In all the cases, unacceptable discrepancies at individual level for clinical purposes were noted. The following equation was developed and showed a better agreement with the deuterium dilution method: TBW = 13.8994 + 0.0017 × Age +0.3190 × Weight +1.8532 × Sex.

CONCLUSION

Further development and cross-validation of anthropometric and BIA prediction equations specific to African heamodialysis patient are needed. Meanwhile, the equation developed in this study which provided a better agreement with the isotope dilution could be use for Cameroonian haemodialysis patients.

Effect of drying and cooking on nutritional value and antioxidant capacity of morogo (Amaranthus hybridus) a traditional leafy vegetable grown in South Africa

Morogo (vegetables in Tswana) is a green leafy vegetable from the Amaranthaceae family that can be harvested from wild growing or cultivated. The objective of this study was to determine the nutritional value, the total antioxidant capacity and selected bioactive compounds present in morogo leaves, and evaluate the effect of drying and cooking. Results showed that morogo contained a significant amount of protein (3.6 ± 0.1 g/100 g FW) and minerals which the level exceed 1% of fresh weight. The total antioxidant capacity (μmole TE/ 100 g FW) determined by DPPH and FRAP assays were 118.3 ± 15.3 and 128.4 ± 11.9 respectively. Total polyphenols (109.4 ± 7.5 mg GAE/100 g FW), vitamin C (36.6 ± 1.0 mg /100 g FW) and carotenoids represented by β carotene (25.3 ± 1.3 mg /100 g FW) and xanthophylls (7.48 ± 0.31 mg /100 g FW) formed a significant part of bioactive compounds content of morogo leaves. Since the boiling can cause significant losses of compounds in the boiling water, it can be recommended to avoid cooking methods that can include a boiling step with discard of boiling water.

Breastfeeding practices of Cameroonian mothers determined by dietary recall since birth and the dose-to-the-mother deuterium-oxide turnover technique

Exclusive breastfeeding during the first 6 months of infant's life is a public health recommendation and important factor for the promotion of optimal growth, health and behavioural development of each child. The accuracy of the mothers' self-reported past infant-feeding events was examined and compared with the isotopic dilution technique. Breastfeeding practices were assessed in a sample of 44 Cameroonian mother-infant pairs using dietary recall since birth. Intakes of breast milk and non-breast milk water were measured in the same sample using the dose-to-the-mother deuterium-oxide turnover technique and compared with questionnaire. Results showed that mothers' self-reported behaviour overestimates the exclusive breastfeeding rate. Seventy-five per cent of the mothers who claimed to be exclusively breastfeeding were found to be predominantly or partially breastfeeding by the dose-to-the-mother deuterium-oxide turnover technique. Only 11% of the infants were exclusively breastfed, and the breast milk output was not significantly affected (P ≤ 0.05) by the mother's body composition. Mean intakes of breast milk and non-breast milk water were 701 mL day(-1) and 268 mL day(-1), respectively. Introduction of non-breast milk foods is associated with a reduction in the level of breast milk intake, but the difference in breast milk intake was not significant between exclusively and predominantly breastfed infants. In conclusion, the dose-to-the-mother deuterium-oxide turnover technique can be applied to validate the mother's reports of infant-feeding practices, but non-breast milk water intake by breastfeeding category still needs to be normalized.

Validity of impedance-based equations for the prediction of total body water as measured by deuterium dilution in Cameroonian HIV-infected patients treated with antiretroviral treatment

BACKGROUND & AIMS

No information is available on the validity of impedance-based equations for the prediction of body composition in Cameroonian HIV-infected patients treated with antiretroviral drugs. Equations for the prediction of total body water (TBW) have the tendency to be population-specific, and this may be due to biological factors, such as variable body geometry and physiological state. We tested the validity of equations derived from different racial backgrounds for predicting TBW from bioelectrical impedance analysis measurements.

METHOD

The TBW content of 56 Cameroonian HIV patients (19 men and 37 women) treated with the first-line ARV regimen was measured by deuterium dilution and compared with those predicted by 12 equations developed respectively in samples of white, black, black and white, or unspecified racial background subjects.

RESULTS

Pure errors in predicting TBW showed acceptable value for all the equations tested. Four equations (three from whites and one from blacks and whites) yielded a non-significant bias; however, equation H which presented the narrower 95% confidence interval and the smaller pure error was recommended for the prediction of TBW in Cameroonian HIV-infected patients treated with antiretroviral drugs. In all other cases, we observed either an overestimation or underestimation of TBW with variable bias values.

CONCLUSION

The absence of a clear trend in cross-validation among equations according to their origin and the probable effect of physiological state should encourage further exploration of the causes of the lack of validity.

Salts soaking treatment for improving the textural and functional properties of trifoliate yam (Dioscorea dumetorum) hardened tubers

Processing of Dioscorea dumetorum hardened tubers into flour could be a means of adding a longer-term value to this tropical plant with a high nutritional potential, but which presents a postharvest hardening problem characterized by a hard-to-cook defect. In an attempt to investigate the changes leading to salts soaking treatment of hardened tubers, the central composite rotatable design for K= 2 was used to study the combined effect of NaCl concentration (0% to 6%) and pH (4 to 10) on tubers cooked hardness, and 6 kanwa alkaline salt concentrations (1:3 (w/v); 0%, 0.2%, 0.5%, 0.8%, 1%, and 1.5%; pH 11.3 +/- 0.2) were used to study the effect of kanwa treatment on tuber cooked hardness and functional properties of resulting flours. The results showed that salts soaking treatment significantly decreased (P</= 0.05) tubers cooked hardness, independently of the solution pH, but could not totally overcome the tubers hardening phenomenon, as a consequence of the multiple mechanisms of D. dumetorum tuber hardening. Nevertheless, kanwa concentrations of 0.8% to 1.5% could be used to tenderize hardened tubers prior to its transformation in flour. Except oil absorption capacity, initial soaking of hardened tubers in kanwa solutions significantly influenced (P</= 0.05) the functional properties of the resulting flours. Water absorption capacity increased with increasing of kanwa concentration while the other properties evaluated (water solubility index, hydrophilic-lipophilic index, bulk density, swelling capacity, least gel-forming concentration) decreased.