1,720,960 research outputs found
Product optimization of Zambian traditionally fermented milk - mabisi
No full textFermented dairy products are an important part of the human diet because they provide nutrients and extend the shelf life of raw milk, which is perishable. In Africa, there are several traditionally fermented milk products (TFMPs) mostly, produced at household level for domestic consumption such as mabisi from Zambia. Mabisi is made by spontaneous fermentation of raw milk at ambient temperature in a calabash, plastic or metal container for two days. The main aim of this study was to characterise the microbial community composition of mabisi and optimise its production process. Thus, a survey was carried out to determine the different production practices/methods of mabisi, key production parameters, uses and microbial community composition. Then, a laboratory experiment was carried out to determine the effect of fermentation temperature on the quality of mabisi and its microbial community composition. Furthermore, a field experiment was also conducted to determine the microbial dynamics of three types of mabisi. We found seven different production methods of mabisi, which include tonga, barotse, backslopping, illa, creamy, cooked and thick-tonga mabisi. Tonga mabisi was found to be the most popular and widely produced mabisi variant throughout the country by all ethnic groups. The key production parameters identified were: type of fermentation container, fermentation temperature, backslopping, alternate removal of whey in combination with addition of raw milk, heating and cooling, fermentation time and finally, agitation (churning). We further found that mabisi is a versatile product with various uses. The microbial community composition of mabisi from across the country was unravelled and showed that the top 10 most abundant genera were Lactococcus, Lactobacillus, Streptococcus, Enterobacter, Klebsiella, Kluyvera, Aeromonas, Acinetobacter, Buttiauxella and Citrobacter, which belong to two phyla, Firmicutes and Proteobacteria. The microbial community composition was affected by geographical location, production method, type of producer, fermentation container, pH and fermentation time. Furthermore, the production of mabisi in the country was divided into two main regions, (i) the traditional mabisi production region (TMPR) and (ii) the non-TMPR. The products found in TMPR were dominated by lactic acid bacteria (LAB) while the products from non-TMPR were characterised by a diverse community of non-LAB but with Lactococcus lactis driving the fermentation process in these products. Tonga mabisi had a more complex and diverse microbial community composition than the rest and was widely produced in non-TMPRs. The fermentation temperature, which was one of the key production parameters showed that tonga mabisi fermented at tap water temperature (20°C), room temperature (22°C), constant temperatures of 25° and 30°C retained a complex and diverse microbial community composition with Lactococcus as the main LAB driving the fermentation. In addition, the use of single or multiple batches of raw milk for mabisi production as well as the use of a new or previously used container, also did not have an effect on the microbial community composition of tonga mabisi. However, barotse mabisi incubated at 25°C was dominated by Lactococcus and retained moderate pH of 4.2 whereas the one incubated at 30°C was dominated by Lactobacillus and had a much lower pH of 3.2. High incubation temperature (30°C) led to faster fermentation, high levels of syneresis and a low consistency, which is not desirable. The producer and production method of mabisi had an effect on microbial community composition of mabisi. Three types of mabisi produced by four different producers over ten production cycles showed that tonga mabisi retained a more complex and diverse composition than illa and backslopping mabisi after ten production cycles. The 6th and 10th cycles of illa and backslopping mabisi on the other hand were both dominated by Lactococcus and Lactobacillus. In conclusion, this study established the different production methods of mabisi and its uses, the microbial community composition and the factors that affect them and finally, the process conditions required to produce good quality mabisi. This knowledge can be used to develop starter cultures for mabisi in order to standardise production. Alternatively, spontaneous fermentation with standardised process conditions can be employed to produce standardised products.</p
Optimization of the production process and nutritional composition of Zambian Munkoyo and Chibwantu Non-Alcoholic Beverages
Full text linkThis study investigated the optimization of production procedures and nutritional content of Munkoyo and Chibwantu, traditional Zambian non-alcoholic beverages. Key production parameters, such as, pH, Total Titratable Acidity, viscosity, and Total Soluble Solids were evaluated for optimization, while analyses for proximate composition, calcium, iron, and zinc were conducted to assess nutrient content. Results revealed no significant differences in fermentation outcomes between extracts from 100 g and 150 g of dried Munkoyo root (p > 0.05), with pH levels ranging from 3.53 to 3.77 and TTA below 1%. Nutritional analyses indicated that Munkoyo contains 2.7 to 4.1 mg/100 g of calcium, 0.04 to 0.05 mg/100 g of iron, and 0.19 to 0.38 mg/100 g of zinc, while Chibwantu provides 2.4 to 4.7 mg/100 g of calcium, 0.03 to 0.05 mg/100 g of iron, and 0.25 to 0.46 mg/100 g of zinc. The low mineral content suggests supplementation with nutrient-rich ingredients. This research lays a foundation for quality standards and supports the sustainability of Munkoyo root, aiding the growth of Zambia's traditional beverage market
A Manufacture of Kachasu, a Traditional Distilled Liquor in Lusaka, Zambia
No full textThis study examined the manufacturing processes and safety concerns of kachasu, a traditional distilled liquor produced in Zambia and other African countries. Despite being illegal in Zambia, the production and sale of kachasu continues, raising public health concerns due to unsanitary manufacturing conditions and high alcohol content. The research involved key informant interviews with fourteen processors from high-density compounds in Lusaka, revealing the use of raw materials such as maize malt, sugar, water, and starter cultures from previous batches. Seven distinct production methods were identified, each involving spontaneous fermentation and distillation. The alcohol content of kachasu ranged between 20 per cent and 70 per cent, with three different grades collected during distillation. The unsanitary conditions of production, including the use of makeshift distillation equipment and contaminated packaging materials, pose significant health risks. This study highlights the need for regulatory oversight to improve the safety of kachasuand mitigate its potential public health impacts
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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