Optimization of the griddling process of kpejigaou (a traditional low fat nutritious cowpea food) using response surface methodology.

Kpejigaou is a griddled cowpea paste product eaten mainly in West Africa. As its processing does not involve the use of fat, it has the potential of meeting consumers' demand for healthy, low fat nutritious foods. Product texture is considered an important quality index by kpejigaou consumers. The objective of this study was to determine the optimum processing conditions of kpejigaou with respect to its textural properties. The study followed a 2 × 3 design with two processing variables each at three levels as follows: griddling temperature (130, 200, 270 °C) and time (5, 7.5 and 10 min). Texture Profile Analysis (TPA) was done on freshly processed samples. The data were fitted into multiple regression models from which the optimum griddling conditions for kpejigaou were determined. Kpejigaou processed at the optimum conditions was evaluated by untrained consumers for acceptability. Traditionally processed kpejigaou served as the control. The TPA results showed that hardness, chewiness and modulus of deformability were significantly affected by griddling conditions. Adjusted R(2) for the models for hardness, chewiness and modulus of deformability were 96%, 97% and 78%, respectively. Using response surface methodology, the optimum griddling conditions for kpejigaou (for acceptable textural properties) were determined to be 170 °C for 5-6 min. The texture of optimized kpejigaou was very much liked for its higher degree of sponginess as compared to the control. It also had acceptable sensory attributes of color, taste and flavor. These findings provide the basis for the development of a process for mass production and quality assurance of kpejigaou.

Microbiological changes in naturally fermented cassava fish (Pseudotolithus sp.) for lanhouin production.

Cassava fish (Pseudotolithus sp.) was naturally fermented on three different occasions at room temperature (28-30 degrees C) for 3 to 8 days and the microbial population and the occurrence of various bacterial species were monitored. In general, after a slight increase during the early stages of fermentation, the microbial population decreased as the fermentation progressed. A total of 224 isolates belonging to the genera Bacillus, Staphylococcus, Micrococcus, Streptococcus, Corynebacterim, Pseudomonas, Achromobacter and Alcaligenes were isolated from the fermenting fish samples and the predominant ones were identified at the species level. Bacillus spp. and Staphylococcus spp. were the predominant genera and accounted for 48.7% and 27.3% of the total number of isolates respectively. Bacillus subtilis and Bacillus licheniformis, Staphylococcus lentus and Staphylococcus xylosus and Micrococcus luteus were the representative strains isolated during the fermentation. Bacillus spp., Staphylococcus spp. and Micrococcus spp. initiated the fermentation but Micrococcus spp. were few in numbers and died off after four (4) days of fermentation while Bacillus spp. and Staphylococcus spp. persisted up to the end of fermentation. Enterobacteriaceae were fewer in numbers at the start of fermentation (10(2) cfu/g) and their numbers decreased to less than 10 cfu/g after two days of fermentation. Bacillus spp. as well as Staphylococcus spp. isolated possessed moderate proteolytic and lipolytic activities. Micrococcus spp. showed weak proteolytic activity and no lipolytic activity.

Microbiological evaluation of ghanaian maize dough co-fermented with cowpea.

Fermented maize dough meals form a large proportion of people's diet in Ghana. To enhance the nutritive value of these carbohydrate-rich foods, protein complementation was introduced. In this study, microbial ecology of fermenting maize dough fortified with 20% cowpea was investigated. A total of 106 microbial strains were isolated from different batches of the fermenting dough at periodic intervals. Ten genera of microorganisms namely Lactobacillus, Leuconostoc, Saccharomyces, Debaryomyces, Candida, Bacillus, Micrococcus, Klebsiella, Escherichia and Aspergillus were identified, with lactic acid bacteria species being predominant. A lactic count of log 9.9 cfu/g was obtained at the end of 72 h fermentation relative to log 6.6 cfu/g recorded for aerobic mesophiles. At the 12 h fermentation period, the population of yeasts was less than log 1.0 cfu/g, but gradually rose to log 5.36 cfu/g by 48 h followed a slight decline at the end of 72 h fermentation period (log 4.08 cfu/g). Enteric microorganisms that were isolated from the raw cowpea were less than log 1.0 cfu/g at 12 h of fermentation, while the Aspergillus species were isolated from the raw maize and the dough subjected to drying treatment. The growth of inoculated enteropathogenic E. coli and S. typhimurium was inhibited in the cooked, fermented maize-cowpea dough, and at 72 h, they were not within detectable limit. The study concluded that addition of cowpea at 20% level did not affect the natural fermentation characteristics of the maize dough.

Campylobacter, Salmonella, Shigella and Escherichia coli in live and dressed poultry from metropolitan accra.

This study on the microbiology of chicken assessed a total of 97 live birds from three selected farms and 87 carcasses/chicken parts from two supermarkets, two open markets and one wholesale outlet (cold store) in the Accra metropolis. Campylobacter spp. were isolated from 14 (14.4%) gut contents of live birds from three farms. None of the frozen birds were positive for Campylobacter spp. These isolates were sensitive to most common antibiotics but not to ampicillin and tetracyclines. Salmonella spp. were isolated from 7 (7.2%) gut contents and 13 (6.8%) carcasses and were resistant to erythromycin. cefotiam, penicillin, ampicillin and cefadroxil. Samonella spp. had varied susceptibilities to nalidixic acid, chloramphenicol and minocyclin. No Shigella spp. was isolated from any of the live birds but 6 (6.9%) of imported chicken samples from the cold store and two markets were positive. Fosfomycin and chloramphenicol were the only antibiotics effective against these isolates. Twelve different Escherichia coli serovars were identified from the total of 21 positive samples. These, in order of magnitude isolated, are E. coli 0158 (14.3%), 0125 (14.3%), 025 (9.5%), 028ac (9.5%), 0159 (9.5%). 015 (9.5%), 0126 (9.5%), 063 (4.8%), 0143 (4.8%), 026 (4.8%), 078 (4.8%), 0164 (4.8%). Cefadroxil, ampicillin, penicillin, cefotiam, tetracycline and erythromycin were ineffective against all strains of E. coli isolated. Minocyclin was effective against all strains with the exception of E. coli 0159, 025, 0164 and 063, which were moderately susceptible. All strains with exception of E. coli 0164 were susceptible to fosfomycin. Nalidixic acid, chloramphenicol, kanamaycin, ceftrioxone and amoxycillin all showed varied effectiveness against the strains isolated. It is concluded that imported and locally produced chicken is a potential source of multiple-antibiotic-resistant enteropathogenic bacteria. Measures to improve the microbial quality of chicken are discussed.

Aerobic spore-forming bacteria and chemical composition of some Nigerian fermented soup condiments.

A total of 97 strains of spore-forming Bacillus were isolated from 45 samples of three Nigerian fermented condiments, obtained from retail markets located in Southwestern Nigeria. The isolates were identified as B. subtilis (33%), B. pumilus (19%), B. licheniformis (22%), B. brevis (9%), B. megaterium (12%) and B. polymyxa (5%). The microbial load of the condiments showed that the average count of spore-formers was between 107 to 109 cfu/g. The moisture contents of iru, ugba and ogiri were 57.18%, 46.32% and 42.34%, respectively, while the protein contents were 18.26%, 17.17% and 17.96%. The percentage fat was 29.88%, 40.25% and 44.14% for iru, ugba and ogiri. The ash content ranged from 5.8 to 6.1%; a 0.1% titratable acidity and pH values above 7.0 were obtained for the three condiments.