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Study explores bitter taste of honeybush tea http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6127Study explores bitter taste of honeybush tea Jorisna Bonthuys<p>​​​​​​​<span class="ms-rteFontSize-2">​​ What makes some cups of honeybush tea taste bitter and others not?</span></p><p><span class="ms-rteFontSize-2">This is the topic explored by Lara Alexander as part of her PhD study. Alexander is a student in Stellenbosch University’s Faculty of AgriSciences in the Department of Food Science. She will be receiving her doctoral degree in December. </span></p><p><span class="ms-rteFontSize-2">Alexander investigated phenolic compounds in both “unfermented” (green) and fermented honeybush tea as potential indicators of bitterness. These (natural) plant c ompounds are responsible for the colour of honeybush and other herbal teas, contribute to the health benefits associated with drinking it and are also involved in its flavour properties.</span></p><p><span class="ms-rteFontSize-2"></span><span style="font-size:11pt;">This is also the first study to investigate the reduction of bitter intensity of tea infusions due to the honeybush fermentation processes. </span></p><p><span class="ms-rteFontSize-2">“Bitterness is not acceptable in honeybush tea, known and marketed for its characteristic and pleasant sweet taste,” Alexander points out in her thesis. Some batches of <em>Cyclopia genistoide</em>s (traditionally known as “coastal tea”) have a bitter taste profile. This species is one of the Cyclopia species currently cultivated for the production of honeybush tea. “Bitterness is even more prominent in the unfermented herbal tea,” she writes. “Yet, there is great variation in the bitterness of honeybush infusions, and the compounds responsible for this taste deviation have not yet been identified.” </span></p><p><span class="ms-rteFontSize-2">Alexander has been working on honeybush tea under the mentorship of Prof Lizette Joubert (her supervisor) since 2013 when she started in a temporary research assistant position. Joubert is a specialist researcher working on bioactive compounds and indigenous tea at the Agricultural Research Council (ARC). “It was an ideal position as I was working in a professional environment with absolute experts in the field. The topic of honeybush tea and the interdisciplinary nature of the work intrigued me and I continued to complete both my MSc and PhD in her (Joubert’s) laboratory.”</span></p><p><span class="ms-rteFontSize-2">The study employed different research methods, including a descriptive sensory analysis of hot water extracts and fractions enriched in phenolic compounds like benzophenones, xanthones and flavanones. Alexander also developed a statistical model that can be used to help screen plant material used for tea production in future. </span></p><p><span class="ms-rteFontSize-2">She considered the effect of fermentation on bitter intensity and the content of hot water infusions. These infusions were prepared from genotypes of two of the 23 known honeybush species. Both species studied (<em>C. genistoides</em> and <em>C. longifolia</em>) contains high levels of xanthone and benzophenone and have been found to produce bitter infusions, she points out.</span></p><p><span class="ms-rteFontSize-2">The two species differed in terms of bitter taste, phenolic content and response to fermentation. Different genotypes of the same species also produced infusions varying in phenolic composition and bitter intensity. <em>C. genistoides</em> produced bitter-tasting infusions even after fermentation, whereas the bitter taste of C. longifolia infusions was adequately reduced by fermentation.</span></p><p><span style="font-size:11pt;">“The results indicated that the benzophenone-rich tea fraction was not bitter, the flavanone-rich fraction was somewhat bitter, and the xanthone-rich fraction was distinctly bitter,” Alexander points out in her study. “Bitter taste reduction through fermentation was more effective for<em> C. long</em><em>ifolia</em> than for <em>C. genistoides</em>, highlighting the problem the industry often faces with inconsistent production batches.”</span></p><p><span class="ms-rteFontSize-2">As several phenolic changes that affect compound concentrations take place during fermentation, care should be taken when plant material is chosen for propagation and cultivation, Alexander notes. </span></p><p><span class="ms-rteFontSize-2">Currently, demand for honeybush tea far outstrips supply. Most of the honeybush (about 80%) is wild harvested and the rest is cultivated. Growing the industry not only requires the expansion of commercial cultivation, but also the cultivation of plant material delivering higher yields and consistent quality. The ARC’s honeybush breeding programme is evaluating honeybush genotypes for improved product yield and quality, among others. </span></p><p><span class="ms-rteFontSize-2">“Honeybush is indigenous to South Africa and we hope that it will achieve the same popularity of the wider known rooibos industry,” says Alexander. “By supporting a local South African industry, we hope to achieve a socio-economic impact in support of the local economy,” she concludes.</span></p><p><span class="ms-rteFontSize-2">The research was funded by the ARC (NRF-DST) professional development programme and the NRF Swiss-South Africa Joint Research Programme (SSAJRP). Alexander’s co-supervisors are Prof Daleen de Beer and Nina Muller.</span></p><p><span class="ms-rteFontSize-2"><strong>More about honeybush tea</strong></span><br class="ms-rteFontSize-2"><span class="ms-rteFontSize-2">Although the earliest record of the early Cape colonists using honeybush tea as a medicinal plant dates back to 1830, South Africa’s honeybush industry is still relatively young. </span></p><p><span class="ms-rteFontSize-2">Like rooibos, honeybush is a uniquely South African herbal tea and endemic to the fynbos region. It is made from the leaves and stems of the indigenous Cyclopia shrub that grows in areas ranging from Piketberg (in the Western Cape) to Port Elizabeth (in the Eastern Cape).</span></p><p><span class="ms-rteFontSize-2">Each of the 23 known honeybush species – all belonging to the genus Cyclopia – has a characteristic distribution in nature. Some species prefer sandy, coastal plains, while others flourish on cool, moist mountain slopes. </span></p><p><span class="ms-rteFontSize-2">Both fermented (oxidised) and unfermented (green) honeybush teas are produced for global markets. Consumers are increasingly interested in honeybush tea because of its unique flavour and health properties. Honeybush can also be used in value-added foods, dietary supplements and cosmetics.</span></p><p><span class="ms-rteFontSize-2"><strong>For media enquiries:</strong></span></p><p><span class="ms-rteFontSize-2"><strong>Lara Alexander</strong></span><br class="ms-rteFontSize-2"><span class="ms-rteFontSize-2">Contact: 082 722 7388</span></p><p><span class="ms-rteFontSize-2"><strong>Prof Lizette Joubert</strong></span><br class="ms-rteFontSize-2"><span class="ms-rteFontSize-2">Contact: 021 809 3444 or journbertl@arc.agric.za</span><br></p>
New crab species discovered in Eastern Cape ‘forgotten’ forestshttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6105New crab species discovered in Eastern Cape ‘forgotten’ forestsDane McDonald<p>​A new 'pearl white' freshwater crab species has been discovered in the 'forgotten' Eastern Cape forests of South Africa.<br></p><p>Prof Savel Daniels, a molecular taxonomist at Stellenbosch University, says crabs are relatively well studied in South Africa but for some reason forests have been neglected in sampling efforts.</p><p>“Nobody has ever intensively sampled the forests in the Eastern Cape where we (incidentally) found the species at Mbotyi," he told the FBIP.</p><p>The study formed part of the Eastern Cape Forest project, one of the Large Integrated Projects funded by the Foundational Biodiversity Information Programme (FBIP).</p><p>Mbotyi is a picturesque forested region northeast of Port St Johns and adjacent to the East Coast of South Africa.</p><p><strong>'Sympatry'</strong></p><p>The crab, which shimmers in the presence of light, was collected from under stones found in small streams which flow towards the coast.</p><p>In a case of what phylogeographers call 'sympatry' the pearl white crab lives alongside a known rust brown species belonging to the African freshwater crab genus <em>Potamonautes.</em></p><p><em><img class="ms-rtePosition-2" src="/english/faculty/science/PublishingImages/News%20items/Crabfigure5.jpg" alt="" style="margin:5px;width:300px;" /></em> </p><p>Like a divorced couple who still share the same house, the two related [but genetically distinct] populations are sympatric because they exist in the same geographic area and thus frequently encounter one another without breeding.</p><p>In a sense Daniels was lucky to have discovered the specimen with its striking colour difference compared to its counterpart, <em>P. sidneyi</em>. </p><p>In recent times and particularly with invertebrates, such discoveries, where the scientist has a clear morphological difference as a 'lead' for identifying a potential new species, are rare.</p><p><strong>'Colour morphs'</strong></p><p>In Daniels' line of work he often encounters 'cryptic species' where animals which are similar to the human eye are genetically very different. In other cases animals look different but show no significant genetic differences – different 'morphs'.</p><p>Daniels set out to answer whether the two crabs were indeed different species, or less spectacularly, two superficial 'colour morphs' with the one being pearl white and the other rust brown.</p><p>Back in the laboratory at the Stellenbosch University Evolutionary Genomics Facility samples from both groups of animals were subjected to DNA sequencing, looking at three genes known by geneticists as 'COI, 12S rRNA, and 16S rRNA'.</p><p><strong>DNA sequence divergence</strong></p><p>The DNA sequence divergence (i.e. the genetic difference) for the COI gene, usually a primary marker in animal genetic studies, was striking at 13.42%. </p><p>To gain a better perspective on divergence values molecular taxonomists need to look at which values from prior studies were used to designate something as sufficiently different to be called a 'new species'. </p><p>Daniels' paper, published in the <em>Journal of Crustacean Biology</em>, cited two prior studies with values ranging from 2.8% to 14.7% in the one, and 7.9% between two species in the other.</p><p>There could be no doubt that the shimmering pearl white specimen from Mbotyi was a new species to science.</p><p>Daniels found no morphological characteristics with which to distinguish <em>P. sidneyi</em> from the new Mbotyi species except for the striking colour difference. The latter was inspiration for the naming of the new species, one of the few opportunities for creativity in describing a new species.</p><p>As a tribute to the Xhosa people of the Mbotyi region Daniels decided to give the newly discovered crab the species epithet of <em>mhlophe</em>, meaning 'white' in isiXhosa.</p><p>He says the discovery is important as it highlights the biodiversity of the area, and further establishes the region as a 'biodiversity hotspot', a tourism draw card.</p><p>“Tourism in the region creates a lot of sustainable job opportunities," he says.</p><p>The Foundational Biodiversity Information Programme (FBIP) is a long-term programme to generate, manage and disseminate foundational biodiversity information and knowledge to improve decision-making, service delivery and create new economic opportunities.</p><ul><li>FBIP on Facebook and Twitter<br></li></ul><p>For more details contact:</p><p>Contact:             Dane McDonald  </p><p>Designation:     Science communicator</p><p>Cell:                 +27 (0) 72 1299 649</p><p>Email Address: d.mcdonald@sanbi.org.za</p><p>Website:                           http://fbip.co.za/<br></p><p><br> </p>
Real-time translation of sheet music to Braille in the classroomhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6099Real-time translation of sheet music to Braille in the classroomWiida Fourie-Basson<p>​​A Computer Science student from Stellenbosch University, Cameron Raven, developed a software programme that can translate sheet music to Braille and vice versa in real time.<br></p><p>Cameron developed the system specifically to assist in the teaching of music up to Grade 3 level at the <a href="https://www.pioneerschool.org.za/about/">Pioneer School</a> for the Visually Impaired in Worcester. The work was done as part of his BSc Honors project in Computer Science under the guidance of <a href="http://www.cs.sun.ac.za/~lvzijl/">Professor Lynette van Zijl</a>, well-known for her work on computer-assisted technologies for the blind and deaf.</p><p>Cameron says his program differs from similar systems in that it can be used in real time in the class room: “Teachers will be able to translate from a digital version of sheet music to Braille and send the file over a local area network to the learners' Apex machine at their desk. The Apex machine then reads and interprets this file to give the equivalent Braiile Music Notation for the learner to use and read the music," he explains. </p><p>The learners will also be able to write their own music on their Apex machines which is then saved in Braille and sent back to the teacher. The music is again converted to sheet music for the teacher to read. </p><p></p><p>Mr Hannes Byleveldt, Deputy Principal at the school, says music as a subject has been taught at the school since its inception in 1877: “Music is one of the most important building blocks in the development of the blind learner and is the source of much joy and meaning in their lives. Several of our learners follow the UNISA curriculum, which means they will be able to study music after school."</p><p>One such example is former learner Michelle Nell, currently enrolled for an MA in Music Education at Stellenbosch University.</p><p>The school is also home to the South African Braille Music Library, the only library of its kind in the Southern Hemisphere. With nearly 1 300 titles, ranging from beginners' pieces to complex pieces by composers such as Beethoven and Lizt, it serves users from all over Africa.<br></p><p>Earlier this year, SU and the Pioneer School signed a collaboration agreement with the view to support e-learning and enhance the quality of education at the school.<br></p><p>“With the help and support from Stellenbosch University, we want to use technology to revolutionise the teaching and use of braille in the classroom and in real life," Mr Byleveldt says.<br></p><p>As part of the collaboration agreement, the Computer Science Division also donated six Lenovo desktop computers to the school. The computers became available after the upgrading of equipment in the Natural Science's Computer Usage Areas. Mr Andrew Collett, senior technical officer in the Computer Science Division and an MSc student, made sure the computers were technically ready for the school to use.</p><p>“Now they only have to tell us what is the next project on their wish list for 2019," concludes Prof. van Zijl.<br></p><p><em>On the photo, from left to right, Ms Elizma Berlyn (marketing), BSc student Cameron Raven, Prof. Lynette van Zijl, Mr Andrew Collett, Mr Hannes Byleveldt (deputy principal) and Mr Michael Bredenkamp, principal of Pioneer School.</em><br></p><p><br> <br></p>
Physics student scoops two awardshttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6100Physics student scoops two awardsMedia and communication, Faculty of Science<p>​Scott Cameron, a postgraduate student in Physics, is the recipient of both the Meiring Naudé medal for the best BScHons student in Physics as well as the Dean's Medal for the best BSc-student in the Faculty of Science at Stellenbosch University.<br></p><p>Scott, who matriculated from the <a href="http://www.schoolofmerit.co.za/">Heartwell Private School</a> in Johannesburg, says he has always been excited about the idea of gravitational ways, quarks and strings, but only applied to study Physics as his second choice. However, when he was accepted for Physics, he knew it was the right choice for him.</p><p>“I have worked really hard over the last few years, but not because I wanted that piece of paper which says I have a degree. My motivation has always been to know and understand things, and to learn useful skills along the way."</p><p>His advice to fellow students is to learn “anything and everything" from your own and other fields: “It will help you to get a new perspective on the problem you are trying to solve. Being able to apply skills from other fields in your specific area of expertise will always give you an edge above the rest. Don't just live in one box."</p><p>He is currently pursuing an MSc in Physical and Mathematical Analysis, focusing on numerical approximations for Bayesian model comparison specifically aimed at neural network applications to large datasets.</p><p>He explains that “with this approach, one can compare quantitatively how well different models describe a particular dataset using intelligent search methods to optimize hyperparameters."<br></p><p>Scott says he is honoured and grateful for the awards, and the recognition of his hard work: “It will certainly help me to stay motivated and continue working harder for my MSc and possibly PhD."</p><p>The John Todd Morrison Medal for Best MSc student in Physics in 2017 went to Philipp Uhrich for his thesis “Noninvasive measurement of dynamic correlations in spin systems", which he completed under the guidance of Prof. Hermann Uys, holder of the CSIR/SU research chair in Quantum, Optical and Atomic Physics, and Prof. Michael Kastner from the National Institute for Theoretical Physics (NiTHEP).<br></p>
Co-enzyme A is kinghttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6083Co-enzyme A is kingMedia and communication, Faculty of Science<p>One of the most important molecules in the human body was the centre of attention at StellenCoA2018, the third international conference on <a href="https://www.stellencoa2018.co.za/">Coenzyme A in Health, Disease and Bioscience</a>. The meeting took place at the Stellenbosch Institute for Advanced Studies (STIAS) from 28 October to 1 November 2018.</p><p>Coenzyme A (CoA) plays a crucial role in the energy metabolism of the cell as it initiates the Krebs cycle, the process by which living cells break down organic fuel molecules to harvest the energy they need to grow and divide. It is also central to the metabolism of fats. </p><p>However, more and more scientists are finding that it also has an important role in cell signaling, and consequently can haves a wide-ranging impact on diseases such as cancer, diabetes,as well as  immune response and neuronal functions.</p><p>Studies about how disease-causing organisms make and use CoA themselves (which is often different from the manner in which humans do this) also offers hope in the fight against antibiotic-resistant bacteria, and the parasites that cause malaria.</p><p>Professor <a href="/english/faculty/science/biochemistry/research/strauss-group">Erick Straus</a>s, a biochemist in the Department of Biochemistry at SU and chair of the organizing committee, says researchers engaged in this breadth of studies on CoA are seldom gathered at a single conference: “The conference's unique focus on a metabolite rather than a specific disease allowed us to invite speakers from a range of research fields. Researchers and especially postgraduate students were thus exposed to the multi- and interdisciplinary approach to research that is so essential to this field, and was able to learn from the often complementary approaches we each take to study the biological roles of this molecule." </p><p>The meeting drew praise from several participants for the quality of the scientific programme, and the excellent location. Said one attendee: “It was a wonderful meeting for the community, and a once-in-a-career experience."</p><p>The next conference will take place in the United States in 2020.<br></p><p><br></p>
SU launches SA's first centre for food safetyhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6071SU launches SA's first centre for food safetyJorisna Bonthuys<p style="text-align:justify;">​​​​​​​​Efforts to support food safety in South Africa received a significant boost when Stellenbosch University (SU), in conjunction with Tiger Brands, launched the on-campus Centre for Food Safety (CFS) this week.<br></p><p style="text-align:justify;">This new centre, the first of its kind in the country, will be a unique applied food science research consortium comprised of scientists working at SU and in the food industry. The centre will conduct research on food safety; provide expert advice to the industry, policymakers, and other stakeholders; and promote consumer awareness.</p><p style="text-align:justify;">The centre will be situated in SU's Department of Food Science in the Faculty of AgriSciences, and managed independently by the University. Tiger Brands, one of the founding members, has given R10 million to help establish the centre.</p><p style="text-align:justify;">The centre's advisory board consists of renowned international scientists, including Prof Wilhelm Holzapfel (president of the International Committee on Food Microbiology and Hygiene), Prof Mieke Uyttendaele (from the Department of Food Safety and Food Quality at Ghent University in Belgium) and Prof Stephen Forsythe (former professor of microbiology at Nottingham Trent University in Britain).</p><p style="text-align:justify;">“Food safety is everyone's responsibility," Prof Pieter Gouws, acting director of the CFS, stated at the launch of the centre yesterday. “We want to provide stakeholders with the opportunity to develop and exchange knowledge, experience and expertise in food safety, food defence and food processing." The aim is to provide a blueprint for improved food safety assurance in South Africa, he explained.</p><p style="text-align:justify;">In his keynote address, Prof Pier Sandro Cocconcelli (an expert in food microbiology from the Università Cattolica del Sacro Cuore in Italy) reported on global food safety trends, declaring it a phenomenon that ought to be managed on a global scale. “We need food safety standards and regulations that are clear and (we need to) consider economic impacts and trade issues. We also need to promote long-term thinking among risk managers and policymakers."</p><p style="text-align:justify;">According to Mr Lawrence MacDougall, CEO of Tiger Brands, “food safety is an essential public health issue. With the global increase in the prevalence of foodborne diseases, science-based food controls are essential for the protection of food products."</p><p style="text-align:justify;">MacDougall emphasised that improving South Africa's food management system remains crucial to Tiger Brands. He envisions the CFS playing a pivotal role in driving food safety forward across the industry through means of collaboration. “This is far bigger than Tiger Brands - it is a national imperative," he added.</p><p style="text-align:justify;">According to SU's rector, Prof Wim de Villiers, establishing the centre is in line with Maties' vision of being innovative and conducting world-class research in service of society. “SU wants to help overcome food safety issues by doing research for impact in collaboration with others," he said. “We are tackling a grand challenge to society."</p><p style="text-align:justify;">“After the recent listeriosis outbreak in South Africa, it is clear that this centre (the CFS) is an absolute necessity," said Gouws. “The outbreak, considered the worst of its kind in South Africa so far, left many consumers worried and confused. It has also raised questions about regulatory oversight, as well as standards in the local industry." There is an urgent need for a food safety authority to help protect citizens' health and food security, Gouws argued. “Access to trusted, independent and credible food safety research, knowledge and advice remains critical," he claimed. “We need to ensure that the science we do translates into impact."</p><p style="text-align:justify;">The consequences of a failed food safety system are extremely costly, according to Prof Gunnar Sigge, chairman of the Department of Food Science. “In a developing country such as South Africa, food safety is an important way to ensure that everyone has access to enough food." With the worldwide increase in food-related diseases, developing countries bear the most significant burden, he indicated. Africa has the highest global incidence of food-related diseases and associated deaths across all age groups.</p><p style="text-align:justify;">“A food safety revolution is needed," Gouws asserted. “Risks related to food safety must be scientifically evaluated, and need input from a range of experts. There is also a need for practical communication about food safety based on the best available science."  There is much misinformation out there, affecting food producers and consumers alike. “Science-based food controls are essential for the protection of food products," he said.</p><p style="text-align:justify;">Dr Khotso Mokhele, chairman of Tiger Brands, described the recent listeriosis crisis as “a painful reminder" that even robust and stringent food safety standards need improvement. “A more collaborative approach is necessary across industry, government and academia to empower consumers and improve efforts to ensure food safety. We need adequate standards and (need) to galvanise our efforts to strengthen our food system."</p><p style="text-align:justify;">The CFS is to serve as a hub for such collaborative efforts at promoting food safety and innovation. “This centre has the potential to be a gamechanger for food safety," Mokhele concluded.</p><p style="text-align:justify;"><strong>About the department</strong></p><p style="text-align:justify;">SU's Department of Food Science is rated among the top 75 in the world. It is the leading food science department in Africa and the only one on the continent to be accredited by the International Union of Food Science and Technology. It celebrates its 66th anniversary this year.</p>
Food connoisseur or cooking amateur, how well do you know you spices?http://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6070Food connoisseur or cooking amateur, how well do you know you spices?Dr Janine Colling<p style="text-align:left;"><strong>​</strong><strong>What is food adulteration and how does it occur? </strong></p><p style="text-align:left;"> The price of herbs is determined by how compact the product is (Black et al., 2016). A common adulterant is therefore the addition of bulking agents such as leaves from other plants. These adulterants often go unnoticed since most herbs are sold dried, chopped and ground (Black et al., 2016). Adulteration of products result in economic and financial losses, it can pose a health threat to the consumers and result in loss of confidence in the product. </p><p style="text-align:left;"><strong>Parsley, oregano, thyme or olive leaf ?</strong><img class="ms-rtePosition-2" src="/english/faculty/science/CAF/Documents/spices%20met%20name.jpg" alt="" style="margin:5px;width:333px;height:274px;" /></p><p style="text-align:left;">Oregano, thyme and parsley are herbs which are frequently used for culinary purposes. Oregano and thyme both belong to the family Lamiaceae, whilst parsley belongs to the Apiaceae family. Studies have found that olive leaves are commonly used as an adulterant of oregano spice (Marieschi et al., 2010; Bononi and Tateo, 2011). Visually, the roughly ground products appeared distinguishable (Fig. 1). However, when finely ground, few characteristics (except colour) enable the products to be distinguished from each other. In this application note, we tested the ability of NIR hyperspectral imaging to distinguish between authentic spices and an adulterant. </p><p style="text-align:left;"> Fresh leaves of oregano, thyme, parsley and olive have characteristics that make them recognizable. In a dried and ground state, it is more challenging to identify the products, although they still appear different. Finely ground material have few characteristic properties that can be related back to the original product. </p><p style="text-align:left;"><strong>Can HSI distinguish between true spices and the adulterant ? </strong></p><p style="text-align:left;">The finely ground material was imaged with the SWIR camera which collects the spectra in the 950 – 2500 nm spectral range. The average spectra of the various products looked similar (Fig. 2A). Exploratory analysis using PCA showed that the various authentic spices could be separated into four different clusters (Fig. 2B). A PLS-DA calibration can be generated and used for routine screening of samples to verify authenticity of samples. Chemical maps facilitate visualizing chemical differences between samples by means of different colours (Fig. 2C). </p><p style="text-align:left;"> </p><p style="text-align:left;"><img class="ms-rtePosition-2" src="/english/faculty/science/CAF/Documents/hyperspectral%20images.jpg" alt="" style="margin:5px;width:505px;height:367px;" /> <strong>Figure 2:</strong> Multivariate data analysis of authentic spices and an adulterant. (A) Spectral plots of spices and olive leaves display similar patterns. (B) Exploratory analysis using Principal component analysis (PCA) can assist with detection of separate clusters for the samples. (C) Chemical maps resemble the chemical differences between the samples. These maps also enable the visualization of the spatial distribution of chemicals within a sample. </p><p style="text-align:left;"><strong></strong> </p><p style="text-align:left;"><strong></strong> </p><p style="text-align:left;"><strong></strong> </p><p style="text-align:left;"><strong>How can NIR spectroscopy be used for industrial applications? </strong></p><ul style="text-align:left;"><li><div> Generate a classification model by imaging different authentic materials using NIR equipment to collect the spectra. </div></li><li><div>Verify the authenticity of all incoming materials by imaging samples and applying the classification model.</div></li><li><div> Other examples of the use of hyperspectral imaging in this industry include assessment of the moisture content in free and packaged oregano (Novo et al., 2016) and analysis of crocin metabolites in saffron (Li et al., 2018). </div></li></ul><p style="text-align:left;"><strong class="ms-rteFontSize-1"></strong> </p><p style="text-align:left;"><strong class="ms-rteFontSize-1">Contact Dr Janine Colling: <a href="mailto:jcolling@sun.ac.za">jcolling@sun.ac.za</a></strong></p><p style="text-align:left;"><strong class="ms-rteFontSize-1"></strong> </p><p style="text-align:left;"><strong class="ms-rteFontSize-1">References for further reading </strong></p><p style="text-align:left;"><span class="ms-rteFontSize-1">Black C, Haughey SA, Chevallier OP, Galvin-King P, Elliott C (2016). A comprehensive strategy to detect the fraudulent adulteration of herbs: The oregano approach. Food Chem 210: 551 – 557 </span></p><p style="text-align:left;"><span class="ms-rteFontSize-1">Bononi M, Tateo F (2011). LC/MS/MS-ESI(-) identification of oleuropein as marker of Olea europaea L. leaves used as a bulking agent in ground oregano and sage. Ital J Food Sci 23: 145 – 151 </span></p><p style="text-align:left;"><span class="ms-rteFontSize-1">Li S, Shao Q, Lu Z, Duan C, Yi H, Su L (2018). Rapid determination of crocins in saffron by near-infrared spectroscopy combined with chemometric techniques. Spectrochim Acta A 190: 283 – 289 </span></p><p style="text-align:left;"><span class="ms-rteFontSize-1">Marieschi M, Torelli A, Bianchi A, Bruni R, (2011). Development of a SCAR marker for the identification of Olea europaea L.: A newly detected adulterant in commercial Mediterranean oregano. Food Chem 126: 705 – 709</span></p><p style="text-align:left;"><span class="ms-rteFontSize-1"> Novo JM, Iriel A, Lagorio MG (2016). Rapid spectroscopic method to assess moisture content in free and packaged oregano (Origanum vulgare L.). J Appl Res Med Aromat plants Plants 3: 211 – 214</span></p><p style="text-align:left;"> </p>
Report on status of biological invasions in South Africa a world firsthttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6065Report on status of biological invasions in South Africa a world firstWiida Fourie-Basson<br><p>Two ecologists from Stellenbosch University, Prof. Brian van Wilgen and Prof. John Wilson, were the lead authors of South Africa's first national report on the status of invasive species, published by the South African National Biodiversity Institute (SANBI) this week.<br></p><p>The report, <a href="https://www.sanbi.org/media/the-status-of-biological-invasions-and-their-management-in-south-africa/"><em>The Status of Biological Invasions and their Management in South Africa 2017</em></a>, is also the first such country-level assessment anywhere in the world that focuses specifically on biological invasions. The report fulfills the legal requirement of the National Environmental Management: Biodiversity Act No 10 of 2004 (NEMBA), which stipulates that SANBI has to submit a report on the status of biological invasions, and the effectiveness of control measures and regulations, to the Minister of Environmental Affairs every three years.</p><p>Van Wilgen and Wilson, both from the <a href="http://academic.sun.ac.za/cib/">DST-NRF Centre of Excellence for Invasion Biology</a> at Stellenbosch University, led a team of 37 editors and authors from 14 different organisations to develop a framework and set of indicators for reporting on the status of biological invasions at a national level.</p><p>According to Wilson, the values assigned to these indicators have now set a baseline against which trends in future can be measured.</p><p>Currently, the scoreboard should set the alarm bells ringing. Using the four indicators as a guideline, the researchers found that the rate of introduction of species is increasing, in line with increases in travel and trade, and currently stands at seven new species per year.</p><p>Of the 2 034 alien species known to have established populations outside of cultivation or captivity, 775 have become invasive. Of these, 107 have caused severe negative impacts on the environment, affecting 80 000 km<sup>2</sup> (1.4%) of the land area. However, current mechanical and chemical control measures reach less than 3-4% of this invaded area per year. Given that spread rates are between 5 and 10% per year, it is clearly not enough to contain or reduce the problem. </p><p>The most worrying indicator is the one measuring the level of success in managing invasions. It stands at only 5.5% despite the fact that at least R12 billion has been spent over the past 20 years.</p><p>The report identifies the lack of adequate planning and monitoring of outcomes (rather than inputs) as a key weakness in the management of biological invasions. Another major challenge is implementation and enforcement of existing regulations. In terms of the NE:BA A&S Regulations, management authorities of protected areas and organs of state in all spheres of government are required to prepare “invasive species monitoring, control and eradication plans" and submit those to the Minister of Environmental Affairs and SANBI. There is, however, a very low level of compliance, and plans have been prepared for only 6% of the country, indicating very limited capacity to implement the regulations.<br></p><p>In a similar vein, while effective protocols have been developed to prevent the legal introduction of high-risk alien species, there is little capacity in place to intercept or prevent the import of potentially damaging invasive species. Currently, DEA has a consistent presence at only one of the 72 official ports of entry, and the brunt of border inspections falls to the Department of Agriculture, Forestry and Fisheries (DAFF). An increase in this capacity would potentially deliver major returns on investment by preventing the introduction of further invasive species. </p><p>Despite these challenges, there have been successes on a local scale. One such example is the use of biological control: of the 60 invasive plant species targeted for biological control thus far in South Africa, 15 species are now under complete biological control, and another 19 species under a substantial degree of biological control.</p><p>Van Wilgen says South Africa is a world leader in this field, and the economic benefits of these interventions have been substantial: “Estimated cost to benefit ratios indicate that, for every R1 invested into biological control, economic losses due to invasive alien plant invasions of between R8 and over R3000 have been avoided."</p><p>The report concludes with a list of key messages to policy- and decision makers which can be used as a starting point for the development of a policy-response by the Department of Environmental Affairs.</p><p>“Ideally, scientists and policymakers should work together to ensure that sound scientifically-based information relevant to policy-makers is appropriately considered when policy is formulated and implemented, but there are numerous factors that can hinder effective collaboration. This report is an attempt to bridge that gap," Van Wilgen concludes.<br></p><p>On the photos above:<br></p><p><em>Pine trees invading a fynbos area near Pringle Bay, within the Kogelberg Biosphere Reserve (a World Heritage Site). Unless these invasion can be contained, we stand to loose 30% of Cape Town's water supply as well as hundreds of endemic plant species. Photo: Brian van Wilgen</em><br></p><p><em>The purple flowers are Patterson's curse (</em><em>Echium plantagineum</em><em>), introduced from southern Europe. It comes to dominate pastures and rangelands, and substantially reduces the production of livestock in these invaded areas. Photo: Brian van Wilgen</em><br></p><p><em>Professors John Wilson (left) and Brian van Wilgen were the lead authors for the first national status report on biological invasions in South Africa. Photo: Wiida Basson</em><br></p><p><br> </p>
More black South Africans are donating bloodhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6052More black South Africans are donating bloodWiida Fourie-Basson<p>​​The South African National Blood Service (SANBS) has succeeded in increasing the proportion of donations from black South Africans fivefold, from 43 269 in 2005 to 246 686 in 2015, while at the same time significantly enhancing the safety of South Africa's blood supply.<br></p><p>These are the findings of a new study, based on ten years of data from SANBS, published in the journal <a href="https://www.ncbi.nlm.nih.gov/pubmed/30265757"><em>Transfusion</em> </a>recently, and is the result of a collaboration between researchers from <a href="https://sanbs.org.za/">SANBS</a>, the <a href="/english/faculty/healthsciences/virology">Division of Medical Virology</a> at Stellenbosch University, the <a href="http://www.sacema.org/page/home">DST-NRF Centre of Excellence for Epidemiological Modelling and Analysis</a> (SACEMA), and international researchers.</p><p>Marion Vermeulen, Senior Manager: Operations Testing at SANBS and lead-author of the study, says SANBS receives around 800 000 blood donations per year and provides blood to nearly 400 000 patients per year: “Over the ten-year period, HIV was detected in 0.2% of the donated blood. Over the same time period there was only one confirmed case of HIV transmission via blood transfusion. This is a substantial improvement over the one to two confirmed cases per year between 2000 and 2005."</p><p><a href="https://www.iol.co.za/news/south-africa/new-risk-model-for-blood-ignores-race-234087">Prior to 2005</a>, blood donations from black South Africans were used selectively and often discarded, due to the higher recorded rates of HIV infection in the black population. At the time, to keep the risk to a minimum, SANBS felt it had no alternative, however controversial, but to using race as a criterion.</p><p>On 3 October 2005, SANBS became the first blood service in the world to implement a highly sensitive donor blood test nationwide, called <a href="https://mg.co.za/article/2008-11-02-we-need-black-blood">individual donation nucleic acid testing </a>(NAT). NAT is a highly sensitive molecular technique, which is able to pick up small amounts of viral nucleic acid, even before the body has started to produce antibodies. It is specifically targeted to detect the Hepatitis B and C Viruses and the Human Immunodeficiency Virus (HIV).</p><p>The ten-year analysis shows that, after the implementation of NAT, there was a substantial increase in the number and proportion of donations from black South Africans. The proportion of first-time blood donors in this group increased from 19% in 2005 to 54% in 2015. Over the same time period, the proportion of regular blood donors also showed a fivefold increase from 5% to 26%.</p><p>The study reports that model-based estimates of the overall risk of HIV transmission through blood transfusion declined to between 3.47 and 0.52 per million transfusions over the period, representing a halving of the risk to recipients.</p><p>“The increase in black repeat donors is particularly encouraging, given that repeat donors provide the bulk of the blood in our blood service, with 76.4% of the total donations from 2005 to 2015," Vermeulen explains.</p><p>Despite this increase in the black donor base, Vermeulen says they need more donors to meet the demand: “During 2018 less than 1% of South Africans donated blood. For most of this year, we had less than three days of blood in stock. We need regular donors, but we also require an increase in our first-time donors to expand the small donor base," she concludes.</p><p>The article, “<a href="https://www.ncbi.nlm.nih.gov/pubmed/30265757">Assessment of HIV transfusion transmission risk in South Africa: a 10-year analysis following implementation of individual donation nucleic acid amplification technology testing and donor demographics eligibility changes</a>", was published online in the journal <em>Transfusion</em>, on 28 September 2018. doi:<a href="https://doi.org/10.1111/trf.14959">10.1111/trf.14959</a></p><p><strong>Media enquiries</strong></p><p>Marion Vermeulen</p><p>SANBS</p><p>Tel: (011) 761 9200</p><p>Mobile: 082 419 0427</p><p>E-mail: <a href="mailto:Marion.Vermeulen@sanbs.org.za">Marion.Vermeulen@sanbs.org.za</a></p><p> </p><p>Dr Eduard Grebe</p><p>SACEMA</p><p>Tel: 021 808-2778</p><p>E-mail: <a href="mailto:eduardgrebe@sun.ac.za">eduardgrebe@sun.ac.za</a><br></p><p><br> </p>
Book celebrates 100 years of natural sciences at SUhttp://www.sun.ac.za/english/Lists/news/DispForm.aspx?ID=6042Book celebrates 100 years of natural sciences at SUMedia and communication, Faculty of Science<p>A book which traces the steps of the first pioneers who laid the foundations for training and research in various disciplines in the natural sciences at Stellenbosch University, will be available from 1 October 2018.</p><p>The book, <em>A Particular Frame of Mind – Faculty of Science, Stellenbosch University, 1918-2018</em>, also documents the contributions of various individuals to the establishment of research fields such as nuclear physics and polymer science in South Africa.</p><p>Prof. Chris Garbers, former professor of organic chemistry from 1958 to 1978 and president of the CSIR from 1980 to 1990, writes in the Foreword that key institutions such as the SU's Faculty of Science have contributed “to transforming South Africa from a mainly rural society to an industrial giant on the African continent".</p><p>“The book is a succinct summary covering the past one hundred years, with the exposition of diverse scientific findings in layman's terms, as well as the documentation of anecdotes about various eccentric characters. The book is further enhanced by the insets of colleagues with specialist knowledge and understanding of contemporary developments in science," he continues writing.</p><p>This limited edition red linen hard case book is embossed with foil on the front and spine, and contains more than 200 photographs and images from the SU Archive, the Africana section of the SU Library, and various artefacts from departmental collections, including scientific images of historical and current research.</p><div><img src="/english/faculty/science/PublishingImages/News%20items/Bookpics_for%20SU%20web.png" class="ms-rtePosition-2" alt="" style="margin:5px;" /><span></span></div><p>​“The reader will obtain a vivid and striking view of the particular way of thinking of the historical and current natural scientist," explains Professor Piet Swart, emeritus professor at SU and one of the editors of the book.<br></p><p>According to Professor Louise Warnich, the first female dean of the Faculty of Science, the book is an attempt to provide a comprehensive overview of the first one hundred years of tertiary education and research in natural sciences at the University. Several of the department's founding histories have now been documented for the first time.</p><p>“In the process several staff members took on the challenge to open storerooms and dust off old documents and equipment. In the Department of Botany and Zoology, for example, we found an expenditure book dating from 1918, with entries documenting the buying of 19 rabbits and 20 doves. We also found the oldest photo to date of the very first professor of mathematics and natural science, Professor George Gordon, surrounded by a group of eight students, dating from circa 1880."</p><p>She says the Faculty of Science is very much aware of the scars left by apartheid: “Now, and over the next few decades, we have the opportunity to do things differently. The compilation of this book showed us that what we do today, and how we do it, will make a difference to the lives of those coming after us."</p><p><strong>Book specifications</strong></p><p>Red linen hard case book with foil embossed on cover and spine, covered with a dust jacket with French folds and individually shrink wrapped. Available in Afrikaans or English.</p><p><strong>Paper:</strong> Text printed on 157 gsm Gold East Matt</p><p><strong>Format:</strong> 280mm deep and 280mm wide</p><p><strong>Extent:</strong> 200 full-colour pages plus endpapers</p><p><strong>ISBN English edition</strong>: 978-0-7972-1731-7</p><p><strong>ISBN Afrikaans edition: </strong>978-0-7972-1730-0</p><p><strong>Publication date:</strong> October 2018<strong> </strong></p><p><strong>Price:</strong> R780 (discount available on orders of four and more)</p><p><strong>How to order the book</strong></p><p>To order your copy, send an e-mail to <a href="mailto:science2@sun.ac.za">science2@sun.ac.za</a>, upon which you will receive an invoice with payment details and information about when and where to collect your copy. If the book must be sent via courier, the cost will be added to the price of the book.<br></p>