Thesis--University of Florida. / Description based on print version record. Typescript. Vita. Includes bibliographical references (leaves 39-42).

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Submitted in partial fulfilment of the requirements for the Doctrate Degree in Technology: Food Technology - Durban University of Technology, 2013. / A pearl millet (Pennisetum glaucum) based instant beverage powder (PMIBP) was prepared from two different varieties of pearl millet (Agrigreen (AgG) and Babala (Ba)) by a combination of malting and extrusion cooking. The millet grains were germinated (30oC and 98% RH for 36 h), kilned (50oC for 48 h), cooled to room temperature, ground and stored in a chiller at 5oC until used. The raw and malted pearl millet grains were extruded under different parameters to accommodate the types of pre-treatment applied to the pearl millets. Combination processing of the pearl millet grain was achieved by extrusion of malted pearl millet of both varieties individually, and as a mixture of raw and malted pearl millet (50:50). The effect of the processing methods on the physical, functional, nutritional and biochemical properties of the raw and processed pearl millets varieties were evaluated. Combination processing led to a significant (p ≤ 0.05) decrease in total fat and total dietary fibre (TDF) (3.85 and 22.99 g/100 g, respectively) content of AgriGreen (AgG) extruded malted pearl millet (EMPM); a decrease in TDF (18.12 g/100 g) content of AgG extruded raw pearl millet-malted pearl millet mix (ERPMMPM). Combination processing led to a decrease in ash, total fat, total dietary fibre, Fe and Zn (1.76, 3.48, 14.26 g/100 g, 7.78 and 4.74 mg/100 g, respectively) content of Babala (Ba) EMPM. It also led to a significant (p ≤ 0.05) decrease in ash, total fat, TDF, Fe and Zn (1.88, 4.22, 21.71 g/100 g, 7.24 and 4.14 mg/100 g, respectively) content of Ba ERPMMPM. Regardless of the pearl millet variety, malting led to a significant (p ≤ 0.05) decrease in moisture, total, saturated, mono- and polyunsaturated fats, total dietary fibre iron, zinc and protein digestibility; a significant (p ≤ 0.05) increase in total carbohydrates, total phenolic content, antioxidant activity (TEAC) and water solubility index. Extrusion however, led to a significant (p ≤ 0.05) decrease in total dietary fibre, zinc, total phenolic content and protein digestibility; a significant (p ≤ 0.05) increase in ash, total, saturated and monounsaturated fats, total carbohydrates, iron, starch digestibility water absorption index (WAI) and water solubility index (WSI). The beverages of 10% total solids (8% pearl millet + 2% sugar for taste) prepared from the processed pearl millet were offered to an untrained consumer panel consisting of students and staff of the Cape Peninsula University of Technology, under similar sets of conditions in a sensory evaluation room at the Food Technology Department. The following characteristics of the products were rated and scored on a 9-point hedonic scale (1 – like extremely and 9 – dislike extremely): appearance, colour, aroma, flavour, mouth-feel and overall acceptability. In general, Ba RPM was rated 4 - like slightly, and AgG malted pearl millet (MPM) was rated 6 - dislike slightly and all other pearl millet samples from both varieties were rated 5 - neither like nor dislike.

Thesis (PhD)--Stellenbosch University, 2004. / ENGLISH ABSTRACT: The aim of this study was toe stablish a reliable protocol for the production 0 f transgenic pearl millet as this will open new avenues for augmenting the gene pool of this crop. This was achieved by identifying a highly regenerabie genotype and optimisation of a tissue culture system, and biolistic protocol f or stable integration of selected transgenes. Both a negative, herbicide resistance selectable marker gene, bar, and a positive selectable marker gene, manA, were individually introduced in order to identify and establish a reliable transformation protocol. The optimised transformation protocol was then used to introduce an antifungal gene in the genome of pearl millet to enhance resistance to the biotrophic fungus Sclerospora graminicola. S. graminicola, an obligate oomycetous fungal phytopathogen, is the causal agent of downy mildew in pearl millet plants and a major constraint in the production of pearl millet. A single component of antifungal resistance was introduced into the genome of pearl millet, as preliminary work towards determining its role in the total plant defence system. The approach chosen was to introduce a hydrolytic enzyme, 13-1,3- glucanase, from Trichoderma atroviride (formerly T. harzianum), a soil-borne filamentous fungus, capable of parasitizing several plant pathogenic fungi. It was anticipated that introducing this glucanase gene from T. atroviride which degrades glucan in the fungal cell walls, would significantly contribute to the improvement of resistance against downy mildew. Constructs were prepared containing the gene (gluc78) encoding a 78 kDa beta-1,3- glucanase. The constructs were prepared containing the gluc78 gene driven either by a strong constitutive promoter (ubiquitin promoter, exon and intron) or a wound inducible promoter, the potato proteinase inhibitor ilK gene promoter. The wound inducible promoter includes either an AMV leader' sequence or the rice Act1 intron to obtain higher expression levels in the monocotyledonous plant. The transformation efficiency using the particle inflow gun and the herbicide resistance gene, bar, was improved from 0.02% on a MS based medium, to 0.19 or 0.72% with manA as selectable marker gene on MS or L3 based medium, respectively. However, individual experiments, introducing manA as selectable marker gene, resulted in frequencies of 1.2 and 3%. This translated to one transformation event per plate, which contains on average 31-35 pre-cultured immature zygotic embryos. This is the first report of t he successful introduction and expression of a 13-1,3-glucanase encoding gene from a biocontrol fungus not only under constitutive expression but also under wound inducible expression in a plant. Optimisation of genetic engineering of pearl millet, a cereal crop recalcitrant to transformation, and the introduction of an antifungal transgene, was accomplished in this study. Initial results hint that expression of this transgene enhances resistance to S. graminicola. / AFRIKAANSE OPSOMMING: Die doel van die studie was om 'n betroubare genetiese transformeringsprotokol vir pêrel manna te ontwikkel. Hiervoor moes eerstens 'n regenereerbare genotipe geidentifiseer word. Twedens moes 'n betroubare weefselkultuur en biolistiese transformeringssisteem ontwikkel word. Beide die onkruiddoder bestandheidsgeen, bar, en 'n positiewe selektiewe geen, manA, is vir die doel van die projek onafhanklik in die genoom van pêrel manna in gekloneer. Die optimale sisteem is vervolgens aangewend om 'n geen wat potensieël verbeterde bestandheid teen die biotrofiese swam Sclerospora graminicola wat donsige meeldou by plante veroorsaak, in pêrel manna in te kloneer. 'n Enkele komponent van bestandheid is in die genetiese material van pêrel manna in gekloneer as inleidende werk om die rol van hierdie geen in die totale verdedigingsisteem te bepaal. Die benadering wat gekies was, behels die klonering van 'n hidrolitiese ensiem 13-1,3-glukanase, van Trichoderma atroviride (voorheen T. harzianum), 'n grondgedraagde swam, wat op 'n aantal ander plantpatogene fungus kan parasiteer. Die verwagting is dat klonering van hierdie 13- 1,3-glukanase geen van T. atroviride wat die glukaan verteer in die selwande van swamme, 'n groot verbetering tot die bestandheid teen donsige meeldou sal meebring. Konstrukte is voorberei wat die gluc78 geen bevat wat kodeer vir die 78 kDa beta-1,3-glukanase protein. Die konstrukte wat voorberei is bevat die gluc78 geen geinduseer deur of 'n sterk konstituwe promoter (ubiquitin promoter, exon en intron) of deur 'n wond geinduseerde promoter, die aartappel proteinase inhibeerder ilK geen promoter. Hierdie promoter word gevolg deur of 'n AMV leier volgorde of die rys Act1 intron om verhoogde uitdruk vlakke in monokotiele plante te verseker. As die partikel invloei geweer in kombinasie met die onkruiddoderbestandheidsgeen gebruik word, was die doeltreffendheid van transformasie 0.02% op 'n MS gebasseerde groeimedium. 'n Transformasie doeltreffendheid van onderskeidelik 0.19 en 0.72% is verkry wanneer die manA as selektiewe geen gebruik is op MS of L3 gebasseerde medium. Twee individual eksperimente, waar die manA geen as selektiewe geen gebruik is, het gelei tot 'n transformasie doeltreffendheid van 1.2 of 3%. Dit gee 'n gemiddelde van een transformasie per plaat wat 31 tot 35 voorafgekweekte onvolwasse embrios bevat. Hierdie is d ie eerste verslag van d ie suksesvolle klonering en uitdrukking van 'n 13-1,3-glukanasekoderende geen van 'n swam wat as 'n biologiese beheeragent gebruik word. Hierdie is nie alleenlik onder konstitutiewe uitdrukking nie, maar ook 0 nder wond g einduseerde u itdruk in' n p lant. In hierdie studie is die 0 ptimisering van genetiese verbetering van pêrel manna, 'n graan gewas wat gehard is teen transformasie, deur die klonering van 'n bestandheidsgeen in die genoom van hierdie gewas gedoen. Aanvanklike resultate dui daarop dat die uitdruk van hierdie geen lei tot verbeterde bestandheid teen S. graminicola.

Thesis (MTech (Food Technology))--Cape Peninsula University of Technology, 2018. / The aim of this study was to evaluate the physical, chemical and sensory characteristics of non-alcoholic pearl millet beverage produced using isolated and purified cultures of bioburden lactic acid bacteria (LAB). Traditional non-alcoholic pearl millet beverage (TNAPMB) was produced through spontaneous fermentation. The slurry was fermented for 36 h at 37°C while monitoring the microbial growth at 3 h interval. LAB were grown on deMan, Rogosa and Sharpe agar and identified using Vitek 2 system. The initial numbers of LAB were 7.04 log cfu/ml and increased to 8.00 log cfu/ml after 21 h. The beverage was dominated by LAB and contaminants and their survival was in succession. LAB from the genera Leuconostoc, Pediococcus, Streptococcus and Enterococcus were the main fermenting species in TNAPMB. Pearl millet extract (PME) was produced by hydrating pearl millet flour (PMF) with water (1:10, PMF:Water). To the mixture sprouted rice flour (10%), ground ginger (10%) and pectin (0.6%) were added. Stable PME was used in the production of plain non-alcoholic pearl millet beverage (PNAPMB). PME was pasteurized at 98°C for 30 min, hot filled and cooled to 25°C. The fluid was inoculated with Leuconostoc mesenteroides, Pediococcus pentosaceus and Enterococcus gallinarum each at 0.05, 0.075 and 0.1%, respectively, using factorial design and fermented for 18 h at 37°C. The pH of the beverage ranged between pH 3.32 and pH 3.90. L. mesenteroides, P. pentosaceus, E. gallinarum, the interaction between L. mesenteroides and P. pentosaceus and the interaction between L. mesentoroides and E. gallinarum had a significant effect (p ˂ 0.05) on the pH of PNAPMB except the interaction between P. pentosaceus and E. gallinarum (p = 0.631). The total titratable acidity (TTA) of the beverage ranged from 0.50 to 0.72%. All cultures had a significant influence (p ˂ 0.05) on the TTA of the beverage with the exception of the interaction between L. mesenteroides and E. gallinarum (p = 0.102). However, Monte Carlo simulation showed that E. gallinarum caused an increase in the pH and a decrease in the TTA of the beverage. During fermentation, the pH of the beverage is desired to decrease while the TTA increases, hence E. gallinarum was removed. The interaction between L. mesenteroides and P. pentosaceus at 0.05% and 0.025%, respectively produced an acceptable PNAPMB with potential for commercialization. Furthermore, moringa supplemented non-alcoholic pearl millet beverage (MSNAPMB) was produced by adding 4% of moringa (Moringa oleifera) leaf powder extract during the production of PNAPMB. The physicochemical, nutritional, microbial (LAB) and sensory characteristics of the PNAPMB, MSNAPMB and TNAPMB were determined. LAB were significantly (p < 0.05) affected by the fermentation period and increased from 3.32 to 7.97 log cfu/ml and 3.58 to 8.38 log cfu/ml in PNAPMB and SNAPMB, respectively. The pH of PNAPMB decreased from pH 5.05 to pH 4.14 while the pH of MSNAPMB decreased from pH 5.05 to pH 3.65 during the 18 h fermentation. The growth of LAB during fermentation had a significant effect (p < 0.05) on the pH of the beverages. The TTA increased from 0.14 to 0.22% and increased from 0.17 to 0.38%, in PNAPMB and MSNAPMB, respectively. The TTA of the beverage was affected significantly (p < 0.05) by the 18 h of fermentation. The protein content was 1.62, 2.17 and 1.50% in PNAPMB, MSNAPMB and TNAPMB, respectively. PNAPMB sample was deemed acceptable in comparison to the MSNAPMB. The total colour difference (ΔE) was 5.91 and 10.60 in PNAPMB and MSNAPMB, respectively in comparison to the TNAPMB. Volatile compounds with beneficial effect such as anti-inflammatory and anti-pathogenic properties were identified in the beverages. Principal component analysis indicated that the variations in characteristics of PNAPMB and MSNAPMB could be explained using total fat, saturated fat, total sugar, ash, moisture, proteins, chroma (C), hue and b*. The results showed that isolated pure cultures could be used as starter cultures in the production of non-alcoholic cereal beverages at a commercial level with predictable quality and safety properties.

Millets are C4 annual grasses that are mainly used for food and feed. This thesis describes two studies that evaluated drought tolerance of pearl millet cultivars (Pennisetum glaucum [L.] R. Br) grown for grain. A third study is also included in the thesis that evaluated foxtail millet (Setaria italica [L] Beauv) and pearl millet grown as cover crops and forage during a pasture renovation. The main focus of the thesis involved evaluation of Senegalese pearl millet cultivars for drought tolerance. Drought is one of the most important threats to pearl millet production in Senegal as it limits yield in most parts of the country. Although water stress on pearl millet is common during the growing season, a little is known about how terminal drought affects yield in Senegalese pearl millet cultivars. To address this issue, two field experiments were conducted in 2014 and 2015. The first field study evaluated 20 pearl millet cultivars under water stress and categorized based on their yield response. Whereas the second year field trial used four cultivars from the first field trial in a more detailed study to give recommendations for farmers in Senegal. The experiments were complete randomized block designs. Pearl millet cultivars were grown under irrigation until flowering then the stress treatment was applied by stopping the irrigation in half of the plots. Eleven cultivars showed a statistical indifference to water stress and considered the most drought tolerant. Four cultivars were selected from the 11 for the second year experiment. Of these, cultivar 4 (ICMV IS 89305) and 10 (SOSAT c 88) exhibited higher tolerance to terminal water stress based on evaluation of yield components and drought stress indices. These cultivars could be a good target for further breeding and selection in Senegal. Although the cultivars were more drought tolerant, both had relatively low total biomass. When used in a larger scale, these cultivars could potentially benefit farmers in Senegal and enhance food security. The second part of this thesis addressed use of a forage type millets – specifically foxtail and pearl millet. In the US, these millets are primarily serve as a summer cover crops that can be used for forage. The objective of this experiment was to compare yield and forage quality of foxtail and pearl millet cover crops and their effect on subsequent pasture establishment. A field experiment was conducted in Virginia in 2014 to address this objective. Pearl millet and foxtail millet were randomly planted in 12 plots each and harvested in late summer. Plots were then converted to tall fescue (Schedonorus phoenix (Scop.) Holub) pasture. Foxtail millet had a significantly higher soil cover than pearl millet but the two species did not differ in terms of total biomass, forage quality, or their effect on tall fescue pasture establishment. / Master of Science

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Zugl.: Berlin, Techn. Univ., Diss.

Thesis (D.Phil.)(Botany)--University of Pretoria, 2006. / Includes summary. Includes bibliographical references.