An investigation of the phytochemistry and biological activity of Asparagus laricinus

Thesis (D. Tech. (Biomedical Technology)) -- Central University of Technology, Free State, 2014Medicinal plants are part of indigenous people‟s cultural heritage, thus since ancient times treatment of various diseases using medicinal plants has been part of human culture. The value of medicinal plants to mankind has been very well proven. It is estimated that 70% to 80% of people worldwide rely mainly on traditional health care systems, especially on herbal medicines (Stanley and Luz, 2003). In many societies the medicinal properties of plants were discovered mostly through trial and error, but use was also influenced by the belief systems of the people involved and often became entangled with religious and mythical practices (Mathias et al., 1996). Besides that, medicinal plants are proving to be rich resources of constituents that can be used in drug development and synthesis. Medicinal plants have been a source of a wide variety of biologically active compounds for many centuries and have been used extensively as crude material or as pure compounds for treating various disease conditions. Between 1% and 10% of plants out of an estimated 250 000 to 500 000 species of plants on earth are used by humans (Boris, 1996). 2 Plants used for medicinal purposes contribute significantly to the development of major medical drugs that are used today. Most common medicines have compounds extracted from plants as their primary active ingredients and many have provided blueprints for synthetic or partially synthesized drugs (Simpson and Ogorzaly, 2001). There has been a major resurgence of interest in traditionally used medicinal plants, with a number of international and local initiatives actively exploring the botanical resources of southern Africa with the intention to screen indigenous plants for pharmacologically active compounds (Gurib-Fakim et al., 2010; Rybicki et al., 2012). South Africa is considered a “hot spot” for biodiversity and more than 22 000 plant species occur within its boundaries. This represents 10% of the world‟s species, although the land surface of South Africa is less than 1% of the earth‟s surface (Coetzee et al., 1999). Plants have also been used by man for various purposes, among others as arrow and dart poisons for hunting, poisons for murder, hallucinogens used for ritualistic purposes, stimulants for endurance and hunger suppression, as well as medicine (Duke et al., 2008; Cragg and Newman, 2005). A derivative of the polyhydroxy diterpenoid ingenol isolated from the sap of Euphorbia peplus (known as “petty spurge” in England or “radium weed” in Australia), which is a potential chemotherapeutic agent for skin cancer, is currently under clinical development by Peplin Biotech for the topical treatment of certain skin cancers (Kedei et al., 2004; Ogbourne et al., 2004). Combretastatin A-4 phosphate, 3 a stilbene derivative from the South African bush willow, Combretum caffrum, acts as an anti-angiogenic agent causing vascular shutdowns in tumors (Newman et al., 2005; Holwell et al., 2002). Further reliance on plants for drug development is demonstrated by the use of galantamine hydrobromide, an alkaloid obtained from the plant Galanthus nivalis used traditionally in Turkey and Bulgaria for the treatment of Alzheimer‟s disease (Howes et al., 2003; Heinrich and Teoh, 2004). The plant chemicals used for the above-mentioned purposes are secondary metabolites, which are derived biosynthetically from plant primary metabolites (e.g. carbohydrates, amino acids and lipids). Secondary metabolites are organic compounds that are exclusively produced by plants and that are not directly involved in the normal growth, development and reproduction of a plant (Firn and Jones, 2003). Yet, they have many functions that are important for the plant‟s long-term health and appearance. Plants, being stationary, have to cope with a number of challenges, including engineering their own pollination and seed dispersal, local variation in the supply of the simple nutrients that they require to synthesize their food and the coexistence of herbivores and pathogens in their immediate environment. Plants have therefore evolved secondary biochemical pathways that allow them to synthesize a spectrum of organic molecules, often in response to specific environmental stimuli, such as herbivore-induced damage, pathogen attacks, or nutrient deprivation (Reymond et al., 2000; Hermsmeier et al., 2001). 4 The biosynthesis of secondary metabolites is derived from the fundamental processes of photosynthesis, glycolysis and the Krebs cycle to afford biosynthetic intermediates which, ultimately, result in the formation of secondary metabolites also known as natural products (Dewick, 2002). It is hypothesized that secondary metabolism utilizes amino acids and the acetate and shikimate pathways to produce “shunt metabolites” (intermediates) that have adopted an alternate biosynthetic route, leading to the biosynthesis of secondary metabolites (Sarker et al., 2006). Modifications in the biosynthetic pathways that produce secondary metabolites are probably due to natural causes (e.g. viruses or environmental changes) or unnatural causes (e.g. chemical or radiation processes) in an effort to adapt or provide longevity for the plant (Sarker et al., 2006). Plants‟ secondary metabolites can be classified into several groups according to their chemical classes, such alkaloids, terpenoids and phenolics (Harbone, 1984; Wink, 2003)

Food Safety and Functionality Assessment of Kombucha Systems Through Bacillus cereus Spore and Probiotic Inoculations

Kombucha is a SCOBY-fermented tea beverage known for its taste, sensorial qualities, and high endogenous microbial load. In recent years, kombucha has become a popular functional food with a compound annual growth rate of 25% from 2015 to 2020 in American kombucha sales alone, and sales are predicted to keep increasing significantly over the next decade. However, kombucha is lacking in scientific research, and there is still much to be explored regarding its safety and native probiotic content. This research looked into the various routes of contamination of several kombucha systems as well as the feasibility of the producing a kombucha beverage with health-promoting characteristics derived from the inclusion of lactic probiotics. Although bacterial spore contamination and survival in the kombucha SCOBY have been documented, it is unknown whether spores can survive in the liquid, or whether they can be transmitted to daughter SCOBYs. The foodborne pathogen and spore-former Bacillus cereus was inoculated into the SCOBY, unfermented liquid, and fermented liquid of three different kombucha systems. Data suggest that neither the route of contamination nor the kombucha system influenced the transmission or survival of B. cereus spores. The spread of the spores between culture and liquid across generation was shown to be sporadic but possible, so hygienic handling of kombucha cultures and raw materials throughout the entire production process is crucial to prevent uptake of pathogenic organisms. There was no survival of B. cereus spores after short-term storage or secondary fermentation, indicating that implementation of a holding step may mitigate potential food safety threats. Kombucha is perceived to contain probiotics, but not all live cultures comprise probiotics. Some commercial kombucha products have validated probiotic strains added to them post-fermentation, but this can be costly. If probiotics, such as lactic acid bacteria, are inoculated into sweet tea prior to fermentation, they may be able to acidify the tea, replacing the need for utilizing previous kombucha or acetic acid, or survive and/or produce beneficial metabolites during fermentation in great enough amounts to convey a health benefit upon consumption. The survivability of six probiotic Lactobacillus sp. in acidified, sweetened tea at 25ºC during kombucha fermentation was established, and the medium (tea) and temperature (25ºC) were both revealed to affect the growth rates of the bacteria. Differences in pH indicated that the probiotics were unable to acidify the tea pre-fermentation. Although survival during fermentation was possible for four out of the six probiotics, it was concluded that probiotic Lactobacillus sp. are not well suited for a probiotic kombucha beverages, but out of the tested probiotics, Lactobacillus brevis and Lactobacillus fermentum were the most promising candidates

2021 Student Symposium Research and Creative Activity Book of Abstracts

The UMaine Student Symposium (UMSS) is an annual event that celebrates undergraduate and graduate student research and creative work. Students from a variety of disciplines present their achievements with video presentations. It’s the ideal occasion for the community to see how UMaine students’ work impacts locally – and beyond. The 2021 Student Symposium Research and Creative Activity Book of Abstracts includes a complete list of student presenters as well as abstracts related to their works

INTSORMIL 2005 ANNUAL REPORT

The 2005 INTSORMIL Annual Report presents the progress and notable achievements by the SorghumiMillet CRSP during the period of July 1, 2004 - June 30, 2005. These results are an outcome of partnerships between scientists at six U.S. Land Grant Universities (Kansas State University, Mississippi State University, University of Nebraska, Purdue University, Texas A&M University and West Texas A&M University) and scientists of the Agricultural Research Service of the U.S. Department of Agriculture at Tifton, Georgia and National Agricultural Research Systems (NARS) and National Universities in nineteen countries in Central America, West Africa, East Africa and Southern Afflca. Agricultural research provides benefits not only to producers of agricultural products but also to processors and consumers of agricultural products. Agricultural research has proven itself continuously in providing improved products of greater quantity and quality, as well as improved health to consumers and broad-based economic growth which goes beyond producers and consumers

Effect of curing conditions and harvesting stage of maturity on Ethiopian onion bulb drying properties

The study was conducted to investigate the impact of curing conditions and harvesting stageson the drying quality of onion bulbs. The onion bulbs (Bombay Red cultivar) were harvested at three harvesting stages (early, optimum, and late maturity) and cured at three different temperatures (30, 40 and 50 oC) and relative humidity (30, 50 and 70%). The results revealed that curing temperature, RH, and maturity stage had significant effects on all measuredattributesexcept total soluble solids

Microbial Diversity of the Symbiotic Colony of Bacteria and Yeast (SCOBY) and its Impact on the Organoleptic Properties of Kombucha

Kombucha is an effervescent fermented tea beverage that is gaining popularity for its probiotic nature and purported health benefits. The market for kombucha is expected to reach $1.8 billion by the year 2020. The composition of microbes that compose the symbiotic colony of bacteria and yeast (SCOBY) is highly variable with some species commonly found from the Gluconobacter, Acetobacter, Zygosaccharomyces, Saccharomyces, and Schizosaccharomyces genera. It was hypothesized that different SCOBYs, obtained from different sources would vary in microbial diversity and produce different biochemical and flavor profiles in the resulting beverage over several generations. Kombucha is a fermented product and ethanol is often present in the final beverage, so it is important that a quality control method exist. The main objectives of this research were: (1a) to investigate the microbial variation between three SCOBYs of different origins and (1b) determine if there are significant differences within SCOBYs over 10 generations; (2) to determine the impact that the kombucha SCOBY has on the biochemical profile of the beverage; and (3) to learn the vocabulary words that consumers use to characterize the flavor notes in kombucha. Kombucha was produced in a laboratory setting with three kombucha SCOBY pellicles prescreened for fermentate heterogeneity by High-performance liquid chromatography (HPLC) analysis. Two batches from each unique SCOBY were produced every 14 days. The liquid from batches 1, 5, 10, and the corresponding mother SCOBY were saved for downstream analysis including DNA sequencing with Oxford Nanopore’s MinION and HPLC analysis. A sensory evaluation study was also conducted to determine the vocabulary that consumers use to describe kombucha. The two main microbes present in the SCOBYs tested in this research were Komagataeibacter xylinus and Gluconobacter oxydans. The diversity of the SCOBY did change slightly with time; however, over ten generations, the slight change in diversity was not significant (p-value \u3e 0.05). By calculating beta diversity, Fisher’s alpha, Shannon diversity, and Simpson diversity, a clearer picture of the diversity of the SCOBY community between SCOBYs of different origins could be determined and demonstrated consortia to be quite different. Investigating the two main microbes in kombucha, K. xylinus and G. oxydans, the Pearson correlations between the microbe and the flavor compounds acidic acid, lactic acid, glucose, fructose and sucrose were determined. K. xylinus was negatively correlated to glucose, fructose, lactic acid and acetic acid, and positively correlated to sucrose (part of the formulation) concentrations suggesting this microbe dominates earlier in the fermentation. G. oxydans was positively correlated to the concentrations of glucose, fructose, lactic acid and acetic acid, but negatively correlated to sucrose, suggesting it dominates later in the fermentation. However, these correlation coefficients were low and not significant. A sensory evaluation study using 66 untrained panelists revealed the top 3 favorite flavors of kombucha amongst these panelists were ginger + other flavorings, ginger, and tropical flavors. Comparing two commercial and one lab-made kombucha sample showed that consumers found a significant difference in the vinegar, sour and bubbly flavor notes