Evaluating the Potential of Juice from Some Sweet Sorghum Varieties Grown In Kenya to Crystallize

Sweet sorghum (Sorghum bicolor (L) Moench) is a crop analogous to sugarcane with similar accumulation of sugars in its juicy stems. An earlier research study on agronomic trials carried out by Jomo Kenyatta University of Agriculture and Technology established that some of the imported varieties of Sweet Sorghum had sufficiently high amounts of sugar content in their Juice. The present study was undertaken with the objective of determining the potential of some of these sweet sorghum varieties to produce crystal sugar. This was with the long term goal of trying to find alternative uses for sweet sorghum. The sweet sorghum varieties were planted at the University research farm, and stalks of sixteen varieties were crushed using electrical roller mill to produce SS juice which was then subjected to a number of analyses including, total and specific sugar determination and apparent purity. The total sugars in degree Brix varied from 15.050 to 21.500, sucrose concentration ranged from 6.05g/l to72.77g/l, glucose 2.65g/l to 16.41g/l and fructose 2.66g/l to 17.16g/l whereas apparent purity(AP) ranged from 33.89% to 83.91%.The variation could have been  brought about by varietal differences. The juice of variety RIO had the highest sucrose purity of 83.91% which was further clarified by liming and double carbonation method. The resulting juice was concentrated into syrup by evaporation. Supersaturation for crystallization was attained by cooling, followed by seeding. According to the present study, the following sweet sorghum cultivars; Rio, CMSXS636, IESV91018LT, IESV93042SH and SPV1411 could have potential in crystal raw sugar production because they have AP greater than 75% and a relatively higher sucrose concentration. The Rio sweet sorghum variety with the highest sucrose purity of 83.91% and sucrose concentration of 40.86g/l was selected and subjected to crystal sugar production processes. The Rio juice subjected to crystallization process failed to produce crystals probably due to the presence of dextran, aconitic acid and starch. Key words: Brix, Sucrose, apparent purity, Clarification, Crystal Sugar,

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century