The Effectiveness of Water, Salt and Vinegar in Reducing the Bacteria Population in Fresh Green Cabbage.

Green cabbage has great nutritional and therapeutical values and is usually used as the main ingredient for preparing fresh vegetable salad for consumption. The aim of this work was to identify the bacteria population in different sections of green cabbage heads obtained from some selected markets in Accra and also to determine the most appropriate method for washing to reduce the bacteria population prior to consumption. In the investigation, samples were obtained from five open markets in the Greater Accra Region of Ghana. Fresh leaves taken from the outer, middle and inner sections of the samples were analyzed for aerobic mesophilic organisms, coliforms and Escherichia coli. They were then washed with tap water, 5% salt solution or 50% vinegar solution for five minutes, and the effectiveness of the treatments in reducing the bacteria population determined. Results from the analysis showed that the outer sections of fresh green cabbage heads had high microbial load followed by the middle sections whilst the inner sections were almost sterile. The aerobic mesophilic counts ranged from 106–108 CFU/g for the untreated outer section of the samples, 104–106 CFU/g for the untreated middle sections, and 101–102 CFU/g for the untreated inner sections. Coliforms ranged from 104–106 CFU/g for the untreated outer section of the samples, 102–104 CFU/g for the untreated middle sections and 101 CFU/g for the untreated inner sections. E.coli ranged from 102–103 CFU/g for the untreated outer section of the samples and 101 CFU/g for the untreated middle sections. E. coli was however not detected in the untreated inner sections of the cabbage heads analyzed. The pathogens Bacillus cereus and Staphylococcus aureus were also identified on the samples from the five markets. The treatment with 50% vinegar solution was most effective in reducing the bacteria population on the samples analyzed followed by 5% salt solution and tap water the least effective. The outcome of this work serves as a basis for creating awareness against the use of ordinary tap water by caterers and promote the use of vinegar or salt solutions as a means of reducing bacteria population in freshly served cabbages. Keywords: Cabbage, Aerobic mesophiles, Coliforms, E. coli, Staphylococcus aureus, Bacillus cereu

BIOACCUMULATION OF HEAVY METALS IN AFRICAN RED SNAPPER (Lutjanus agennes) AND CASSAVA FISH (Pseudotolithus senegalensis) CAUGHT OFF THE COAST OF ACCRA, GHANA

The level of Cu, Fe, Mn, Pb, and Zn in African red snapper (Lutjanus agennes) and cassava fish (Pseudotolithus senegalensis) caught off the coast of Accra, Ghana, were monitored from November 2011 to March 2012 using atomic absorption spectrophotometry. Over the five months period, variations occurred in the level of each of the heavy metals in each of the fish species.  The heavy metals accumulated in the gills and bones more than in the muscle tissues of type of fish. The order of accumulation of the heavy metals in African red snapper in terms of magnitude were Zn>Pb>Fe>Mn>Cu in the bones, Fe>Zn>Pb>Mn>Cu in the gills and Fe>Pb>Zn>Mn>Cu in the muscle tissue.  For cassava fish the order was Fe>Zn>Pb>Mn>Cu in the bones, Fe>Pb>Zn>Mn>Cu in the muscle, and Fe>Pb>Zn>Mn>Cu in the gills. In the muscle tissue, the part of fish which is normally consumed, the mean value for the various heavy metals over the five months period in the African red snapper were Cu, 0.73 mg/kg; Fe,; 8.18 mg/kg Mn, 0.66 mg/kg; Pb, 7.04 mg/kg; and Zn, 5.16  mg/kg. In cassava fish, the mean values in the muscle tissues were Cu, 0.53 mg/kg; Fe, 9.38; Mn, 0.67 mg/kg; Pb, 5.90 mg/kg; Zn, 6.18 mg/kg. The concentrations of the heavy metals found in both fish species were mostly above the safe limits recommended by WHO. Key words: Fish, Heavy metals, accumulation, bioaccumulation, red snapper, cassava fis

Effectiveness of three different storage structures and curing process for the storage of sweet potato (Ipomoea batatas) in Ghana

Three different storage structures and two curing processes for the storage of sweet potato (Ipomoea batatas) were studied at the CSIR-Food Research Institute, Accra. Sweet potato roots initially cured under warm(30-35 °C) and very humid (90-95% relative humidity) conditions for 7 and 14 days were stored in local (traditional), pit, and clamp storage structures for 84 days. After 0-84 days of storage, the roots were sampled and physically assessed into wholesome, sprouted, fungalinfected, and insect and rodent-damaged. The decrease in percentage wholesome roots corresponded to an increase in percentage fungal-infected roots from 0 to 84 days of storage in all the three different storage structures. Clamp storage structure recorded the highest percentage wholesome roots (20.0%) compared to pit (16.3%) and local (0%) after 84 days of storage when roots were cured for 7 days. However, for 14 days cured roots stored for 84 days, local storage structure recorded the highest percentage wholesome roots (20%), pit (0%), and clamp (10%). Higher percentages of fungal-infected sweet potato roots were recorded from roots cured for14 days. Percentage sprouted roots was higher in clamp, followed by pit and local storage structures. Sprouting was delayed for sweet potato roots that were cured for 14 days in all the storage structures. Percentage damage of sweet potato roots by insect and rodent was lower inall the three storage structures compared to the fungalinfected sweet potato roots

Detection of viable Mycobacterium ulcerans in clinical samples by a novel combined 16S rRNA reverse transcriptase/IS2404 real-time qPCR assay.

Detection of Viable <em>Mycobacterium ulcerans</em> in Clinical Samples by a Novel Combined 16S rRNA Reverse Transcriptase/IS<em>2404</em> Real-Time qPCR Assa

Characterization of the dominant microorganisms responsible for the fermentation of dehulled maize grains into nsiho in Ghana

Nsiho (white kenkey) is a type of kenkey, a sour stiff dumpling, produced from fermented maize meal in Ghana. The dominant microorganisms responsible for the fermentation of nsiho were characterized by analysing samples from four traditional production sites at Anum in the Eastern Region of Ghana. During 48 h of steeping dehulled maize grains, the pH values decreased from 6.05 to 5.93 to 3.59 to 3.55, whilst titratable acidity increased from 0.02 to 0.03 to 0.27 to 0.32%. In the subsequent 12 h dough fermentation, the pH decreased from 6.02 to 5.80 to 3.52 to 3.46, whilst titratable acidity increased from 0.25 to 0.27 to 0.35 to 0.38%. The lactic acid bacteria population increased by 2 to 5 log units to concentrations of 107 to 108 CFU/ml during steeping and by 2 to 3 log units from 105 to 106 CFU/g to 108 to 109 CFU/g during dough fermentation. Yeasts counts increased by 3 to 4 log units during steepingand by 2 to 4 log units during dough fermentation. The most frequently isolated lactic acid bacteria responsible for nsiho fermentation were identified as Lactobacillus fermentum (47.1%), Lactobacillus brevis (25%), Lactobacillus plantarum (14.42%), Pediococcus pentosaceus (8.65%) and Pediococcus acidilactici, (4.8%). The dominant yeasts species were Saccharyomyces cerevisiae (47.6%), Candida krusei (29.1%),  Debaryomyces spp., (15%) and Trichosporon spp., (8.3%). This is the first  study to report on the micororganisms involved in nsiho fermentation.Key words: Nsiho, dehulled maize, kenkey, lactic acid bacteria, indigenous African fermented foods

Evaluation of Oxalate Content of Some Indigenous and Produced Spices and Seasonings in Ghana

In this paper, six indigenous (LS) and fifteen industry produced spices and seasonings (IPS)  available to consumer have been examined for its oxalate content using Ultra Violet –Visible spectroscopy with a view to provide useful information towards their effective use. The oxalate content of the LS was found to be between 0.74±0.04 –4.99±0.26 mg/g whereas that of the IPS was between 0.05±0.0-7.5±0.0 mg/g. Although the LS recorded a higher average oxalate content than the IPS, the difference was not statistically significant (p&lt;0.05). Among the IPS samples curry based spices had higher oxalate content. Keywords: anti-nutritional factors, oxalate, seasonings, spices, Ghan

Application of a value chain approach to understanding white kenkey production, vending and consumption practices in three districts of Ghana

Traditional processing and street vending of foods is a vital activity in the informal sector of the Ghanaian economy and offers livelihood for a large number of traditional food processors. Kenkey is a fermented maize ‘dumpling’ produced by traditional food processors in Ghana. Ga and Fante kenkey have received research attention and there is a lot of scientific information on kenkey production. White kenkey produced from dehulled maize grains is a less known kind of kenkey. A survey was held in three districts of Ghana to study production, vending and consumption of white kenkey and to identify major bottlenecks related to production, which can be addressed in studies to re-package kenkey for a wider market. Questionnaires were designed for producers, vendors and consumers of white kenkey to collate information on Socio-cultural data, processing technologies, frequency of production and consumption, product shelf life, reasons for consumption and quality attributes important to consumers using proportional sampling. The survey was conducted in white kenkey production zones and trade centers. Results showed that production of white kenkey is done on small-scale levels by middle-aged women in households with 10-50 kg of dehulled maize processed into white kenkey, 1-3 times weekly. A third (28%) of the women processed up to 50-100 kg of maize per week. Although 62% of vendors sell 50-100 balls of white kenkey daily, 15% of them sell more than 170 balls. Majority of consumers (45.9%) liked white kenkey because of its convenience (ready-to-eat). Texture and taste were quality attributes desired by kenkey consumers. Producers did not have written records of process controls and product throughputs. Inspite of their cottage nature, production of white kenkey is a profitable employment for producers and vendors and is popular among consumers. Product improvement, process and product characteristics could offer scale-up criteria for development of white kenkey production using standardized procedures for steeping times, steeping temperature and fermentation times.Keywords: maize, white kenkey, value chain, traditional, product development, re-engineerin

D 5.5.1.1. Final report on sensory testing in Africa for Group 1. Project AFTER “African Food Tradition rEvisited by Research”

This deliverable concerns the sensory evaluation of the reengineered group 1 African products in the AFTER project. Specifically, it related to reengineered akpan and gowe from Benin, kenkey from Ghana and Kishk Sa'eedi in Egypt. Concerning reengineered akpan from Benin, the sensory evaluation was undertaken in Montpellier, France. Re-engineering of akpan has focused primarily on improvement of sanitary properties of the product, which was a great achievement and will allow producing Akpan on a larger scale in SMEs in Africa. Sensory evaluation of the Akpan products was carried out using CATA and JAR techniques that have been developed for use with consumers instead of a trained panel. Three Akpan products were tested by 102 consumers: Akpan added with 10% sugar (AS10), Akpan added with 3% spray-dried milk and 8.7% sugar (AMS8.7) and Akpan added with 3% spray-dried milk and 15% sugar (AMS15). Independently of the Akpan tasted, Acidity or Sweetness attributes were scored “Just About Right, as I like” by 56 to 77% of consumers. Odour perception was perceived differently, depending on consumers. However, Texture was found “Too weak”, too liquid by the majority of consumers (49 to 55%) and Taste “too strong” (46 to 54%). The most frequently CATA descriptors checked by consumers which better described Akpan products were: “Artificial”, “Floral”, “New/Different”, “Strong in Taste”, “Mealy”, followed by “Liquid”, “Drinking yoghurt”, “Sweet”, “Acidic”, and “Rough”. At the opposite, an ideal-yoghurt was described as Creamy, Natural, Good for health, Refreshing, Homogeneous, with a texture of a Bulgarian yoghurt-type, Thick, Sweet, Attractive, Nutritious and Milk taste. In terms of sensory evaluation, the three Akpan products did not significantly. If we remove the terms such as “artificial”, “strong in taste”, “floral” due to a manufacturing error (use of a few drops of citronella essential oil instead of citronella infusion as a traditional flavouring of Akpan in Benin), it remains the terms “mealy”, “liquid” “drinking yoghurt” that better describe the product and were previously used for describing traditional Akpan product. This suggests that sensory properties of the reengineered Akpan may not be acceptable to French consumers who prefer a product with a creamy, homogeneous, Bulgarian yoghurt-type taste. Gowe in Benin was not tested using sensory evaluation. Sensory testing of Gowe in Benin was not undertaken because this was planned to be undertaken in Europe. The reason is because the methodology used in sensory evaluation is independent of the location provided the samples are the same. However, the particular samples provided for French sensory testing contained a concentration of aflatoxin that was higher than the minimum EU allowable limit. It was not possible to repeat the sensory test in France because it would have taken too long to obtain a replacement supply from Benin and to repeat the processing (takes one week). In which case the samples would have been took different to enable a comparison. The sensory evaluation of kenkey was carried at the Food Research Institute, Ghana. Current trends in urbanization, and the increasing popularity of kenkey among consumers, require larger scale production with consistent quality. Testing was conducted to determine the sensory profile of white reengineered kenkey made using the optimum pre-process conditions of steeping time (30 and 45h), steeping temperature (30ᵒC and 35ᵒC) and dough fermentation time of 12 hours. The qualitative descriptive analysis showed that the sensory profile of white kenkey was dependent on preprocessing variables. Thus merely optimizing the pre-processing variables with regards to acid production and other readily measurable constituents though could shorten the production process could not guarantee the best product sensory quality. The results show that all the descriptors generated were appropriate for differentiating sensory qualities among samples and could be used for basic research and product development for white kenkey. Soft and sticky texture in white kenkey was highly appreciated. Sensory evaluation of Kishk Sa'eedi (KS) was undertaken in Egypt. KS is an Egyptian indigenous wheat-based fermented food prepared traditionally according to the method applied by Upper Egyptians. This work is done to characterize sensory properties and sensory profile of the reengineered KS. Quantitative descriptive analysis (QDA) coupled with principal component analysis (PCA) was used to study the interrelationship among and between sensory attributes. 14 terms regarding appearance, odour, flavour and texture of the samples, was selected and a glossary describing each descriptor was developed. Three KS samples were profiled by 11 assessors using the chosen 14 sensory descriptors. Mean intensity ratings of the descriptive attributes showed that there were significant differences (p<0.05) within KS samples for all the 14 attributes tested. In general, high ratings for creamy colour, fresh odour, KS taste and fracturability are considered as positive effects that would be favoured by panellists while increase in caramel colour, sour taste, denseness and mouth coating are regarded as undesirable. The re-engineered KS sample perceived as less sour and less salty compared with the traditional ones. With regard to texture quality, reengineered sample was easy to fracture, and scored higher for grittiness. Meanwhile, the sample was rated lower than the traditional ones with regard to Kishk taste and fermented odour. Descriptive sensory evaluations between of the traditional and re-engineered KS samples showed that tastes i.e. sour, salty, and KS taste; fracutability and grittiness were discriminating attributes. Fermented odour, colour i.e. creamy and caramel; presence of fissure and presence of bran were least discriminating. Evaluation of the KS sensory characteristics provide in depth understanding of the sensory quality criteria as perceived by the sensory trained panel. The present study showed that substantial differences in sensory character were noted between the traditional and re-engineered KS in particular, differences in colour, fresh odour, KS taste, fracutability and mouth coating. This work showed that the application of QFD and PCA techniques could provide the useful information to KS and helped to identify the importance of product attributes. In conclusion the sensory evaluation showed clear sensory differences between the traditional and reengineered products relating to akpan from Benin, kenkey from Ghana and Kishk Sa'eedi from Egypt. Other deliverables will report on the acceptance by consumers