19 research outputs found
Effects of cowpea fortification and the level of ripeness of plantain on the nutritive value of plantain based snack foods
To investigate effects of cowpea addition and level of ripeness of plantain on the nutritional and sensory characteristics of Kaklo and Ofam in Ghana, A 2X4 factorial experiment with firm and soft ripe plantain and cowpea fortification of 0, 10, 20 and 30% was designed. The proximate composition and acceptability of products using a 7-point hedonic scale were evaluated. With the addition of 30% cowpea, the protein content of the Kaklo from the firm ripe and soft ripe plantain increased from 2.92% to 7.32% and 3.65% to 8.05% respectively, whilst the protein of the Ofam from the firm and soft ripe plantain also increased from 3.80% to 8.45% and 3.75% to 8.15% respectively. The 10% fortified Kaklo and Ofam werethe most acceptable. The cowpea addition significantly affected the nutritional value of the Kaklo and Ofam. To obtain an acceptable cowpea fortified plantain-based snack, the fortification should be done at10%
The microbiota of dried traditional vegetables produced in the Sudan Savannah and Guinea Savannah agro-ecological zones of Ghana
Abstract: Traditional vegetables are an important article of diet of the ethnic groups from the northern parts of Ghana. Such vegetables are preserved by sundrying and consumed throughout the year. These are mostly leafy vegetables and include Hibiscus sabdariffa (sorrel), Bomtax costatum (kapok), Ceratotheca sesamoides, Adansonia digitata, and Hibiscus esculentus (okro), respectively called by the local names shure or sobolo, daala, yaudo, kuuka, and okro (common name). The dominant microbiota of ten common dried traditional vegetables were investigated by enumerating total bacteria, yeasts and moulds, lactic acid bacteria, Bacillus species and coliform bacteria. Isolates were characterized by colony and cell morphology, and by biochemical tests. The water activities of all the dried vegetables were between 0.513 and 0.539. Shuri and bisap had low pH values, between 2.6 and 2.71, whilst the other vegetables had relatively higher pH values ranging from 5.21 to 6.39. Moulds and Bacillus spp. dominated the biota of all the dried vegetables although lactic acid bacteria and coliforms were also isolated in most of these products. Bacterial counts of the dried vegetables were between 10 3 and 10 7 CFU/g. Aspergillus spp, Rhizopus spp, Eurotium spp, Penicillium spp and Aureobasidium spp. were the major genera of moulds identified in the dried vegetables. The dominant Bacillus species in all samples was Bacillus subtilis except in the okro pods and leaves where Bacillus cereus was dominant. The dominant lactic acid bacteria were Lactobacillus plantarum and pediococci. Escherichia coli was not detected in any of the dried vegetables, however, Enterobacter aerogenes was detected in most of the samples. Because of the high microbial levels in the dried vegetables, it is recommended that handling procedures be improved by primarily sanitizing the fresh vegetables prior to drying in solar dryers
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
Consumer Perceptions, Knowledge and Preferences for Aromatic Rice Types in Ghana
Abstract: Even though rice forms a major part of the Ghanaian diet, locally produced rice is not patronized as it should. A survey of 390 rice consumers was conducted in Accra, Ghana to ascertain consumer perceptions, knowledge and preferences for aromatic rice as a basis for quality improvement of local rice. Results showed that most consumers (94.9%) were more familiar with imported rice and this was reflected in their patronage patterns. The reasons why consumers did not patronize locally cultivated rice are poor post harvest handling, non-availability, and the generally perceived poor quality. The few (29%) who consume local rice do so out of the perception that it is inexpensive and has better nutritional quality. Both cooked and raw attributes of rice influence consumer preference. Whilst the appearance of raw rice (Friedman rank mean = 2.86) was critical to consumers' choice, taste and aroma determined consumer preference for cooked rice; being ranked 4.96 and 4.46 respectively. [Nature and Science 2010;8(12):12-19] (ISSN: 1545-0740)
Fruit physical characteristics, proximate, mineral and starch characterization of FHIA 19 and FHIA 20 plantain and FHIA 03 cooking banana hybrids
Longitudinal monitoring of Ehrlichia ruminantium infection in Gambian lambs and kids by pCS20 PCR and MAP1-B ELISA
<p>Abstract</p> <p>Background</p> <p>The epidemiology of <it>E. ruminantium </it>infection in extensively managed young animals is not adequately understood. Thus in this study, we monitored the onset (age at first infection) and kinetics of <it>E. ruminantium </it>infection and antibody response in extensively managed newborn lambs and kids at three sites in The Gambia.</p> <p>Methods</p> <p>We used a nested pCS20 PCR and MAP1-B ELISA in a longitudinal study to monitor the onset (age at first infection) and kinetics of <it>E. ruminantium </it>infection and antibody response respectively, in 77 newborn lambs and kids under a traditional husbandry system at three sites (Kerr Seringe, Keneba, Bansang) in The Gambia where heartwater is known to occur. The animals were monitored for field tick infestation and the comparative performance of the two assays in detecting <it>E. ruminantium </it>infection was also assessed.</p> <p>Results</p> <p>The infection rate detected by pCS20 PCR varied between 8.6% and 54.8% over the 162-day study period. Nineteen per cent of the animals in week 1 post-partum tested positive by pCS20 PCR with half of these infections (7/14) detected in the first 3 days after birth, suggesting that transmission other than by tick feeding had played a role. The earliest detectable <it>A. variegatum </it>infestation in the animals occurred in week 16 after birth. Antibodies detected by MAP1-B ELISA also varied, between 11.5% and 90%. Although there is considerable evidence that this assay can detect false positives and due to this and other reasons serology is not a reliable predictor of infection at least for heartwater. In contrast to the pCS20 PCR, the serological assay detected the highest proportion of positive animals in week 1 with a gradual decline in seropositivity with increasing age. The pCS20 PCR detected higher <it>E. ruminantium </it>prevalence in the animals with increasing age and both the Spearman's rank test (<it>r</it><sub><it>s </it></sub>= -0.1512; P = 0.003) and <it>kappa </it>statistic (-0.091 to 0.223) showed a low degree of agreement between the two assays.</p> <p>Conclusion</p> <p>The use of pCS20 PCR supported by transmission studies and clinical data could provide more accurate information on heartwater epidemiology in endemic areas and single-occasion testing of an animal may not reveal its true infection status. The view is supported because both the vector and vertical transmission may play a vital role in the epidemiology of heartwater in young small ruminants; the age range of 4 and 12 weeks corresponds to the period of increased susceptibility to heartwater in traditionally managed small ruminants.</p
Transmission Electron Microscopy Reveals Distinct Macrophage- and Tick Cell-Specific Morphological Stages of Ehrlichia chaffeensis
Background: Ehrlichia chaffeensis is an emerging tick-borne rickettsial pathogen responsible for human monocytic ehrlichiosis. Despite the induction of an active host immune response, the pathogen has evolved to persist in its vertebrate and tick hosts. Understanding how the organism progresses in tick and vertebrate host cells is critical in identifying effective strategies to block the pathogen transmission. Our recent molecular and proteomic studies revealed differences in numerous expressed proteins of the organism during its growth in different host environments.
Methodology/Principal Findings: Transmission electron microscopy analysis was performed to assess morphological changes in the bacterium within macrophages and tick cells. The stages of pathogen progression observed included the attachment of the organism to the host cells, its engulfment and replication within a morulae by binary fission and release of the organisms from infected host cells by complete host cell lysis or by exocytosis. E. chaffeensis grown in tick cells was highly pleomorphic and appears to replicate by both binary fission and filamentous type cell divisions. The presence of
Ehrlichia-like inclusions was also observed within the nucleus of both macrophages and tick cells. This observation was confirmed by confocal microscopy and immunoblot analysis.
Conclusions/Significance: Morphological differences in the pathogen’s progression, replication, and processing within macrophages and tick cells provide further evidence that E. chaffeensis employs unique host-cell specific strategies in support of adaptation to vertebrate and tick cell environments
EFFECTS OF COWPEA FORTIFICATION, DEHYDRATION METHOD AND STORAGE TIME ON SOME QUALITY CHARACTERISTICS OF MAIZE-BASED TRADITIONAL WEANING FOODS
Fortification of cereal-based traditional foods with legume protein can improve their nutritional value. It is, however, important to find out the extent to which the addition of cowpea affects the desirable quality characteristics of traditional weaning foods prepared from fermented maize and also to assess the effect of dehydration method and storage time on the chemical, physico-chemical and functional properties of the products. A 3 x 2 x 4 factorial experiment with cowpea level, drying method and storage time as the respective variables was done. The traditional weaning food was prepared by steeping maize in water for 24 hours, mixed with cowpea and co-milled into a meal. A 50%-moisture dough was made with the addition of water and fermented for 24 hours. The product was dried using solar drier (40-60 °C for 72 hours) and oven drier (60 °C for 8 hours), and packaged in polypropylene bags prior to the analysis. Proximate analysis, pH, titratable acidity, fat acidity, water absorption and cooked paste viscosity were monitored over six months under tropical ambient conditions (28 °C, RH 85-100%). Cowpea addition caused only minimal changes in the studied indices with the exception of protein content, which increased from 10.54-14.34% and 10.71-14.42% with 20% cowpea level, respectively, for the solar and oven-dried products. Likewise, no major changes in proximate composition were detected during storage. The product pH and fat acidity increased with concomitant decreases in titratable acidity in the stored samples. The pH levels increased from 4.67 – 5.18 and 4.13 - 4.71, respectively, in the solar-dried and oven-dried products within the six months storage period whilst titratable acidity levels decreased slightly during storage of the product. The cowpea level, drying method and storage time showed comparable variations on the cooked paste characteristics measured. The application of cowpea fortification and dehydration to traditional weaning foods is, therefore, a viable option of promoting the nutritional qualities of traditional weaning foods with prolonged shelf life stability.
Key Words: Cowpea fortification, dehydration method, storability, traditional weaning foods, chemical and functional properties.
Effets de l'enrichissement avec du niébé, la méthode de déshydratation et la durée de conservation sur certaines caractéristiques qualitatives des aliments de sevrage traditionnels à base de maïs
Resumé
L'enrichissement des aliments traditionnels à base de céréales par adjonction de protéines végétales (légumineuses) est susceptible d'améliorer leur valeur nutritionnelle. Cependant, il est essentiel de connaître l'étendue des effets de l'adjonction du niébé sur les caractéristiques qualitatives souhaitables des aliments traditionnels de sevrage préparés à partir du maïs fermenté. Il est également important d'évaluer l'incidence que la méthode de déshydratation et la durée de conservation ont sur les propriétés chimiques, physico-chimiques et fonctionnelles des produits. Une expérience factorielle 3 x 2 x 4 a été faite avec comme variables respectifs la concentration de niébé, la méthode de déshydratation et la durée de conservation. L'aliment de sevrage traditionnel a été préparé de la manière suivante : on a laissé tremper du maïs dans l'eau pendant 24 heures, ensuite ce maïs a été mélangé aux niébés. Ce mélange a été broyé et réduit en farine. L'adjonction d'eau à cette farine a donné une pâte moelleuse (50% d'humidité) qu'on a laissée fermenter pendant 24 heures. Le produit a été séché en utilisant le séchoir solaire (40-60 °C pendant 72 heures) et dans un four de séchage (60 °C pendant 8 heures), et emballé dans des sachets en polypropylène avant d'être analysé. L'analyse de la composition, le pH, l'acidité titrable, l'acidité grasse, l'absorption de l'eau et la viscosité de la pâte cuite ont été suivis sur une période de six (6) mois dans les conditions tropicales ambiantes (28 °C, RH 85-100%). L'adjonction de niébé n'a pas causé de changements importants dans les indices étudiés, à l'exception de la teneur en protéines. Celle-ci a augmenté car elle est passée de 10,54 à 14,34% et de 10,71 à 14,42% avec une concentration de niébé de 20% respectivement pour les produits soumis au séchage solaire et ceux dont le séchage a été effectué au four. Il en est de même pour la composition globale : aucun changement important n'a été détecté pendant la conservation. Le pH du produit et l'acidité de la matière grasse ont augmenté tandis que le taux d'acidité titrable a diminué dans les échantillons conservés. Les concentrations du pH ont augmenté : elles sont passées de 4,67 à 5,18 et de 4,13 à 4,71 respectivement pour les produits séchés au soleil et ceux séchés au four pendant une période de six mois, tandis que les taux d'acidité titrable ont légèrement diminué pendant la conservation des produits. La concentration de niébé, la méthode de déshydratation et le temps de conservation ont montré des variations comparables sur les caractéristiques de la pâte cuite qui ont été mesurées. L'application de l'enrichissement avec du niébé et la méthode de déshydratation aux aliments de sevrage traditionnels est donc une option viable pour la promotion des qualités nutritionnelles des aliments de sevrage traditionnels conservés pendant une longue période.
Mots-clés : enrichissement avec du niébé, méthode de déshydratation, aptitude à la conservation, propriétés chimiques et fonctionnelles, aliments de sevrage traditionnels.
AJFAND Vol.4(1) 200
Effets De L&Apos;Enrichissement Avec Du Ni�B�, La M�Thode De D�Shydratation Et La Dur�E De Conservation Sur Certaines Caract�Ristiques Qualitatives Des Aliments De Sevrage Traditionnels à Base De Ma�S
Fortification of cereal-based traditional foods with legume protein can
improve their nutritional value. It is, however, important to find out
the extent to which the addition of cowpea affects the desirable
quality characteristics of traditional weaning foods prepared from
fermented maize and also to assess the effect of dehydration method and
storage time on the chemical, physico-chemical and functional
properties of the products. A 3 x 2 x 4 factorial experiment with
cowpea level, drying method and storage time as the respective
variables was done. The traditional weaning food was prepared by
steeping maize in water for 24 hours, mixed with cowpea and co-milled
into a meal. A 50%-moisture dough was made with the addition of water
and fermented for 24 hours. The product was dried using solar drier
(40-60 °C for 72 hours) and oven drier (60 °C for 8 hours),
and packaged in polypropylene bags prior to the analysis. Proximate
analysis, pH, titratable acidity, fat acidity, water absorption and
cooked paste viscosity were monitored over six months under tropical
ambient conditions (28 °C, RH 85-100%). Cowpea addition caused
only minimal changes in the studied indices with the exception of
protein content, which increased from 10.54-14.34% and 10.71-14.42%
with 20% cowpea level, respectively, for the solar and oven-dried
products. Likewise, no major changes in proximate composition were
detected during storage. The product pH and fat acidity increased with
concomitant decreases in titratable acidity in the stored samples. The
pH levels increased from 4.67 - 5.18 and 4.13 - 4.71, respectively, in
the solar-dried and oven-dried products within the six months storage
period whilst titratable acidity levels decreased slightly during
storage of the product. The cowpea level, drying method and storage
time showed comparable variations on the cooked paste characteristics
measured. The application of cowpea fortification and dehydration to
traditional weaning foods is, therefore, a viable option of promoting
the nutritional qualities of traditional weaning foods with prolonged
shelf life stability.L'enrichissement des aliments traditionnels à base de
céréales par adjonction de protéines végétales
(légumineuses) est susceptible d'améliorer leur valeur
nutritionnelle. Cependant, il est essentiel de connaître
l'étendue des effets de l'adjonction du niébé sur les
caractéristiques qualitatives souhaitables des aliments
traditionnels de sevrage préparés à partir du maïs
fermenté. Il est également important d'évaluer
l'incidence que la méthode de déshydratation et la durée
de conservation ont sur les propriétés chimiques,
physico-chimiques et fonctionnelles des produits. Une expérience
factorielle 3 x 2 x 4 a été faite avec comme variables
respectifs la concentration de niébé, la méthode de
déshydratation et la durée de conservation. L'aliment de
sevrage traditionnel a été préparé de la
manière suivante : on a laissé tremper du maïs dans
l'eau pendant 24 heures, ensuite ce maïs a été
mélangé aux niébés. Ce mélange a été
broyé et réduit en farine. L'adjonction d'eau à cette
farine a donné une pâte moelleuse (50% d'humidité) qu'on
a laissée fermenter pendant 24 heures. Le produit a été
séché en utilisant le séchoir solaire (40-60 °C
pendant 72 heures) et dans un four de séchage (60 °C pendant
8 heures), et emballé dans des sachets en polypropylène avant
d'être analysé. L'analyse de la composition, le pH,
l'acidité titrable, l'acidité grasse, l'absorption de l'eau
et la viscosité de la pâte cuite ont été suivis sur
une période de six (6) mois dans les conditions tropicales
ambiantes (28 °C, RH 85-100%). L'adjonction de niébé n'a
pas causé de changements importants dans les indices
étudiés, à l'exception de la teneur en protéines.
Celle-ci a augmenté car elle est passée de 10,54 Ã
14,34% et de 10,71 Ã 14,42% avec une concentration de
niébé de 20% respectivement pour les produits soumis au
séchage solaire et ceux dont le séchage a été
effectué au four. Il en est de même pour la composition
globale : aucun changement important n'a été
détecté pendant la conservation. Le pH du produit et
l'acidité de la matière grasse ont augmenté tandis que
le taux d'acidité titrable a diminué dans les
échantillons conservés. Les concentrations du pH ont
augmenté : elles sont passées de 4,67 à 5,18 et de 4,13
à 4,71 respectivement pour les produits séchés au soleil
et ceux séchés au four pendant une période de six mois,
tandis que les taux d'acidité titrable ont légèrement
diminué pendant la conservation des produits. La concentration de
niébé, la méthode de déshydratation et le temps de
conservation ont montré des variations comparables sur les
caractéristiques de la pâte cuite qui ont été
mesurées. L'application de l'enrichissement avec du
niébé et la méthode de déshydratation aux aliments
de sevrage traditionnels est donc une option viable pour la promotion
des qualités nutritionnelles des aliments de sevrage traditionnels
conservés pendant une longue période
Quality characteristics of Lanhouin: A traditional processed fermented fish product in the Republic of Benin
Lanhouin, a fermented fish product is processed by spontaneous and largely uncontrolled fermentation. Disadvantages of this type of fermentation are that very little control can be exercised over the fermentation process and the product is often of variable quality with inherent risks of quality defects. Samples of lanhouin processed from cassava croaker /cassava fish (Speudotolithus sp.) or Spanish mackerel / king fish (Scomberomorus tritor), widely used as condiment in Benin, Togo, and Ghana, were purchased from processors and retailers in the processing sites and markets respectively, for product characterization. The samples were obtained from 20 retailers and 20 processors randomly selected in urban and rural processing sites and markets. The samples were transported under aseptic conditions to laboratory for analyses. The chemical composition of samples was determined using Pearson's and AOAC methods. The microbiological status was investigated according to the Nordic Committee on Food Analysis standard methods. The results showed that the pH values of the majority (78.5 %) of samples were above 7 and the water activity values ranged from 0.65 to 0.87. High level of free fatty acids (FFA) and thiobarbituric acid number (TBA) were also recorded for all the samples. Moisture, protein, salt, total volatile nitrogen and histamine contents ranged between 50.1-56.6 %, 24.6 - 26 5 %, 5.2 - 7.3 %, 294.5 - 374.5 mg N / 100 g and 21.4 -33.1 mg / 100 g respectively. Significant differences (p < 0.05) were observed on these parameters within and between species. The histamine contents in most of the samples (75%) exceeded the recommended level of 20 mg / 100 g. The total viable counts of the majority (83.5 %) of the samples were high. Micrococci and bacilli were the predominant organisms enumerated in the products. Their numbers ranged between 3.2 X 104- 6.4 X 105 and 1.6 X 103- 2.6 X 104 respectively. Few numbers of coliform bacteria and Clostridium spp. were enumerated in some of the samples (6 %).No Salmonella and no yeasts were found in any sample. Keywords: fish, fermentation,lanhouin, qualit