Low N2_{2}O and variable CH4_{4} fluxes from tropical forest soils of the Congo Basin

Globally, tropical forests are assumed to be an important source of atmospheric nitrous oxide (N$_{2}$O) and sink for methane (CH$_{4}$). Yet, although the Congo Basin comprises the second largest tropical forest and is considered the most pristine large basin left on Earth, in situ N$_{2}$O and CH$_{4}$ flux measurements are scarce. Here, we provide multi-year data derived from on-ground soil flux (n = 1558) and riverine dissolved gas concentration (n = 332) measurements spanning montane, swamp, and lowland forests. Each forest type core monitoring site was sampled at least for one hydrological year between 2016 - 2020 at a frequency of 7-14 days. We estimate a terrestrial CH$_{4}$ uptake (in kg CH$_{4}$-C ha$^{-1}$ yr$^{-1}$) for montane (−4.28) and lowland forests (−3.52) and a massive CH$_{4}$ release from swamp forests (non-inundated 2.68; inundated 341). All investigated forest types were a N$_{2}$O source (except for inundated swamp forest) with 0.93, 1.56, 3.5, and −0.19 kg N$_{2}$O-N ha$^{-1}$ yr$^{-1}$ for montane, lowland, non-inundated swamp, and inundated swamp forests, respectively

Awareness, handling and storage factors associated with aflatoxin contamination in spices marketed in Dar es Salaam, Tanzania

A structured questionnaire was used to collect information of awareness, knowledge and practices associated with aflatoxin contamination in spices from 30 retailers in Dar es Salaam. Aflatoxin contamination in spices was analysed using high performance liquid chromatography (HPLC) with fluorescence detection using post column derivatization. Data were statistically analysed to assess factors associated with aflatoxin contamination in the study community. 58% of the spice samples were contaminated and the mean of total aflatoxin level in ginger, cinnamon, cloves and cardamom was 2.67, 2.88, 2.79 and 2.26 mu g/kg, respectively. Significant majorities (96.7%) of the respondents were not aware of aflatoxin contamination of spices during storage and its effect on health. Farmers as source where spices were procured and storage time of more than 14 days showed significant association with aflatoxin contamination with odds ratio (OR) = 0.178, 95% confidence interval (CI) = 0.061-0.525, P=0.002 and OR=3.608, 95% CI=1.099-11.845, P=0.034, respectively. This is the first report of aflatoxin contamination in spices consumed in Tanzania. The levels of contamination are high and associated spices that was procured from farmers and long storage time. This calls for urgent raising of awareness and knowledge on good management practices for prevention of aflatoxin contamination of spices in Tanzania

Incidence rates of aflatoxin contamination for each location across and within the two years of 2014 and 2015.

<p>Incidence rates of aflatoxin contamination for each location across and within the two years of 2014 and 2015.</p

Aflatoxin levels in sunflower seeds and cakes collected from micro- and small-scale sunflower oil processors in Tanzania

<div><p>Aflatoxin, a mycotoxin found commonly in maize and peanuts worldwide, is associated with liver cancer, acute toxicosis, and growth impairment in humans and animals. In Tanzania, sunflower seeds are a source of snacks, cooking oil, and animal feed. These seeds are a potential source of aflatoxin contamination. However, reports on aflatoxin contamination in sunflower seeds and cakes are scarce. The objective of the current study was to determine total aflatoxin concentrations in sunflower seeds and cakes from small-scale oil processors across Tanzania. Samples of sunflower seeds (n = 90) and cakes (n = 92) were collected across two years, and analyzed for total aflatoxin concentrations using a direct competitive enzyme-linked immunosorbent assay (ELISA). For seed samples collected June-August 2014, the highest aflatoxin concentrations were from Dodoma (1.7–280.6 ng/g), Singida (1.4–261.8 ng/g), and Babati-Manyara (1.8–162.0 ng/g). The highest concentrations for cakes were from Mbeya (2.8–97.7 ng/g), Dodoma (1.9–88.2 ng/g), and Singida (2.0–34.3 ng/g). For seed samples collected August-October 2015, the highest concentrations were from Morogoro (2.8–662.7 ng/g), Singida (1.6–217.6 ng/g) and Mbeya (1.4–174.2 ng/g). The highest concentrations for cakes were from Morogoro (2.7–536.0 ng/g), Dodoma (1.4–598.4 ng/g) and Singida (3.2–52.8 ng/g). In summary, humans and animals are potentially at high risk of exposure to aflatoxins through sunflower seeds and cakes from micro-scale millers in Tanzania; and location influences risk.</p></div

Recovery of AFB₁ spiked in aflatoxin-free sunflower seed and cakes^a.

<p>Recovery of AFB₁ spiked in aflatoxin-free sunflower seed and cakes<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0175801#t001fn001" target="_blank">^a</a>.</p

Aflatoxin concentrations in sunflower seeds collected from micro- and small-scale sunflower oil processors in Tanzania in the sunflower-harvesting season of 2015.

<p>Aflatoxin concentrations in sunflower seeds collected from micro- and small-scale sunflower oil processors in Tanzania in the sunflower-harvesting season of 2015.</p

The Munkoyo Root : Traditional Uses, Biochemistry, Fermentation, and Potential Cultivation

The munkoyo root is a rich source of amylases used in the production of munkoyo and chibwantu beverages that are widely consumed in Zambia and the Democratic Republic of Congo. The munkoyo plant has several species that grow wildly in the forests and savannas of several southern African countries. Munkoyo is a general term used in Zambia and the Democratic Republic of Congo for a traditionally fermented, cereal-based beverage produced by hydrolysis of gelatinized starch of maize porridge, which is spontaneously fermented by microbes at ambient temperature. The enzymes from the munkoyo root hydrolyze the starch. The munkoyo beverages are consumed by both children and adults (both women and men) in rural and urban areas. Small-scale producers are leading the efforts to commercialize these products in urban areas, which has led to increased demand for the munkoyo root to the point of acute scarcity. This chapter reviews the uses of the munkoyo roots, the production processes of munkoyo and chibwantu beverages, the biochemical aspects of the root and enzymes, the fermentation and microbial composition, and the nutrition and health aspects. This chapter also explores the agronomic potential of the munkoyo plant with a view to commercialize its production thereby ensuring sustainability