Orientadora: Profa. Dra. Natália Pirani Ghilardi-Lopes / Coorientador: Prof. Dr. Gustavo Muniz Dias / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Evolução e Diversidade, São Bernardo do Campo, 2018. / Os ecossistemas bentônicos estão entre os ambientes marinhos mais produtivos e também entre os mais afetados por atividades antropogênicas. Em áreas de costão rochoso como o litoral norte de São Paulo - Brasil, um dos maiores impactos é causado devido ao pisoteio. Essa ação mecânica pode promover danos a estruturas importantes ou até mesmo arrancar o organismo do substrato, afetando a dinâmica das populações e indiretamente a diversidade e o funcionamento da comunidade. As algas marinhas do gênero Sargassum são muito comuns em várias regiões costeiras ao redor do mundo, incluindo a região rochosa subtidal do litoral do sudeste do Brasil, desempenhando um papel importante como estruturadora de habitats e fonte de alimento para muitos organismos marinhos. Desta forma, para avaliar possíveis danos morfológicos e fisiológicos causados pelo pisoteamento, utilizamos uma abordagem experimental baseada em um desenho aninhado em bancos de Sargassum spp. de três diferentes locais, utilizando a metodologia de transectos e nove quadrados de 40 x 40 cm divididos em três tratamentos, simulamos diferentes intensidades de pisoteio: controle (sem pisoteio); baixa intensidade de pisoteio (150 passos sobre as unidades de amostragem) e alta intensidade de pisoteio (300 passos sobre as unidades de amostragem), para testar os impactos esperados em diferentes períodos do ano. Foram quantificados: 1) a performance fotossintética; 2) a concentração de pigmentos fotossintetizantes e compostos fenólicos totais e 3) parâmetros morfológicos e reprodutivos como comprimento, biomassa seca e esforço reprodutivo, imediatamente após o pisoteio e após 90 e 180 dias, totalizando nove conjuntos de tratamento (três intensidades de pisoteio x três períodos de coleta). O pisoteio alterou os padrões fisiológicos causando uma diminuição no desempenho fotossintético e na concentração de pigmentos e aumento de compostos fenólicos totais dependendo do local onde foi realizado o estudo. Considerando os parâmetros morfológicos e reprodutivos, não foram observadas diferenças devido ao pisoteio no comprimento e na biomassa seca, mas o experimento diminuiu significativamente o esforço reprodutivo independente do período ou local estudado. O pisoteio é uma ação humana, por isso é importante conhecer a visão das pessoas sobre o ambiente marinho para a sugestão de medidas mitigadoras de forma mais eficiente. Desta forma, um estudo de percepção ambiental foi realizado com base na escala NEP (New Environmental Paradigm) através do uso de questionários on-line, cujas respostas foram comparadas através do teste de Kruskal-Wallis, considerando gênero, idade, nível educacional, área de trabalho, local de residência, freqüência que visita à praia, número de dias que passam na praia e tipo de atividade ao visitar este ambiente como fatores de agrupamento. Os resultados demonstraram uma consciência dos participantes da pesquisa de que estamos atingindo o limite de recursos que a Terra pode oferecer e que a maioria da interferência humana no meio ambiente é negativa, no entanto, ainda existe uma crença de que os homens são capazes de dominar a natureza e de que os recursos marinhos são ilimitados. Além disso, a maioria dos entrevistados considera que as mudanças climáticas; o aumento do nível do mar e a acidificação do oceano são assuntos tratados com exagero. Entre os fatores avaliados, a idade, o nível educacional, a freqüência de visita à praia e a área de trabalho resultaram em diferenças significativas para algumas das questões, indicando a necessidade do investimento em educação ambiental desde o início da idade escolar e a importância de uma divulgação científica de boa qualidade. Desta forma, as principais conclusões do presente trabalho são: 1) as respostas morfológicas e fisiológicas em Sargassum spp ao pisoteio, dependem do local e do período; 2) a reprodução desta alga é negativamente afetada pelo pisoteio, independentemente do local e do período e 3) a percepção em relação ao ambiente marinho foi influenciada por algumas características das pessoas que participaram do estudo, como idade, nível educacional, área de trabalho e frequência com que visitam a praia. Assim, um gerenciamento eficiente de nossas áreas marinhas e costeiras, deve levar em conta parâmetros ecológicos e sociológicos de cada caso não sendo possível um procedimento generalizado. / Benthic ecosystems are among the most productive marine environments and also among those most affected by anthropogenic activities. In areas of rocky shores as in the northern coast of São Paulo - Brazil, one of the greatest impact is caused due to trampling. This mechanical action can promote damage to important structures or even detach the organisms from the substrate, affecting the dynamics of the populations and indirectly the community diversity and functioning. The seaweeds of the genus Sargassum are very common in several coastal regions around the world including the subtidal rocky-shores from southeastern Brazil, playing an important role as a habitat engineer and food source to many marine organisms. Thus, in order to establish possible morphological and physiological damages caused by trampling on this seaweed, we used an experimental approach based on a nested design. In three diferent sites, using the transect methodology and nine quadrat points of 40 x 40 cm divided into three treatments, we simulated different intensities of trampling: control (no trampling); low trampling intensity (150 steps over the sampling units) and high trampling intensity (300 steps over the sampling units), to mimic the impacts expected along different periods of the year and quantified: 1) the photosynthetic performance; 2) pigment and total phenolics concentration and 3) morphological and reproductive parameters as length, dry biomass and reproductive effort, immediately after the trampling procedures and after 90 and 180 days, totalizing nine treatment sets (three trampling intensities x three times). Trampling changed physiological patterns causing a decrease in the photosynthetic performance and pigment concentration and increasing total phenolics compounds depending on the local where this kind of impact occurs. Considering the morphological and reproductive parameters, trampling significantly decreased the reproductive effort, despite site and period. Trampling is a human action, so it is important to know people's view about the marine environment in order to suggest mitigating measures more efficiently. In this way, an environmental perception study was carried out based on the NEP (New Environmental Paradigm) scale using online questionnaires which responses were compared using the Kruskal-Wallis test considering gender, age, educational level, branch of work, place of residence, frequency of beach attendance, number of days spent on the beach, and type of activity when visiting this environment as grouping factors. The results demonstrated an awareness on the part of the respondents that we are reaching the Earth`s limit and that the majority of the human interference on the environment is negative, however, there was still a belief that men is able to dominate nature and that the marine resources are unlimited. Besides that, most respondents think that climate change; sea level rise and ocean acidification has been treated with exaggerated concern. Amongst the factors tested, the age, educational level, frequency of beach attendance and branch of work resulted in significant differences for some of the questions, indicating the necessity of educational investment since the beginning of the school age and the importance of a scientific dissemination of good quality. The main conclusions of the present work are: 1) morphological and physiological responses to trampling are site and period dependent; 2) reproduction is negatively affected by trampling regardless of site and period and 3) the perception regarding the marine environment was influenced by some characteristics of the people which participated in the study. So, in order to efficiently manage our marine and coastal areas both ecological and sociological parameters must be taken into account and no generalized procedure is possible.

A expansão do consumo de alimentos submetidos a elevado grau de processamento em países em desenvolvimento é notória. Em paralelo, observa-se o aumento na prevalência de excesso de peso e de comorbidades associadas. O fenômeno também tem sido observado em famílias consideradas pobres que recebem benefício financeiro de programa federal de transferência condicionada de renda. O objetivo geral foi analisar o consumo alimentar de beneficiários do Programa Bolsa Família (PBF). Foi elaborado um sistema de classificação de alimentos, de acordo com o propósito e grau de processamento. Os dados utilizados são provenientes do módulo de consumo alimentar pessoal da Pesquisa de Orçamentos Familiares (n = 34.003; 7.600 beneficiários), conduzida pelo Instituto Brasileiro de Geografia e Estatística (IBGE) entre os anos de 2008 e 2009. As observações foram classificadas em três faixas etárias: crianças e adolescentes (10 a 18 anos), adultos (19 a 59 anos) e idosos (60 ou mais anos). Os integrantes da amostra também foram discriminados de acordo com o local do domicílio: regiões Norte, Sul, Nordeste, Centro-Oeste, estado de São Paulo e grupamento dos estados de Minas Gerais, Rio de Janeiro e Espírito Santo. Para estimar o conteúdo de carotenoides presente na dieta um banco de dados foi construído e a composição dessas substâncias nos alimentos foi obtida, prioritariamente, em fonte de dados nacional. Foram levadas em conta as distintas formas de preparo. A ingestão de energia, macronutrientes, fibra alimentar, vitaminas e minerais também foi analisada, com base nas composições dos alimentos divulgadas pelo IBGE. O IMC foi calculado e regressões múltiplas ajustadas aos dados, controlando fatores socioeconômicos e demográficos. Notou-se, destacadamente, que a energia fornecida pelos alimentos ultraprocessados torna-se menor para faixas etárias de maior idade. As pessoas beneficiárias do programa apresentaram tendência para obtenção de menor proporção de energia proveniente desses produtos. A ingestão de fibra alimentar foi, em geral, reduzida (exceto para beneficiários do sexo masculino), assim como de ácidos graxos poli-insaturados, e os ácidos graxos trans foram consumidos em excesso. Verificou-se conteúdo insuficiente (valores médios) de vitaminas E, A, D, folato, B1 (em idosas) e B6 (em idosos), cálcio, potássio, magnésio e fósforo (em meninos e meninas). O sódio foi consumido em excesso. As principais fontes dietéticas da maioria dos minerais foram alimentos minimamente processados e in natura, com exceção do sódio e do manganês. Alimentos processados e preparações culinárias (sem alimentos ultraprocessados na receita) foram importantes fontes de vitaminas C, D e do complexo B, mas também de colesterol, lipídeos e ácidos graxos saturados. A elevada quantidade de ácidos graxos trans contida em alimentos ultraprocessados foi notada. O conteúdo estimado de carotenoides na dieta foi baixo e não integrou intervalos preconizados como seguros. Destacaram-se como fontes dessas substâncias, além das frutas, legumes e verduras, o macarrão preparado com molho de tomate (para licopeno) e as sopas (para ?-caroteno e pró-vitamínicos A). Não foi captado efeito estatisticamente positivo, no IMC, da participação das categorias de alimentos. / The population\'s growing demand for high processed foods in developed countries is well known. At the same time, it is noted an increase of the prevalence of excess body weight and associated comorbidities. The fact has have also been observed among poor families that receive financial support from federal conditional cash transfer programs. The general aim of this thesis was to analyze food consumption of \"Bolsa Família\" Program (BFP) beneficiaries. A food classification system was developed, according to the purpose and processing level. The data used is from the individual food consumption module of a household expenditure survey (n = 34,003; 7,600 beneficiaries) carried out by Brazilian Institute of Geography and Statistics (BIGS) between 2008 and 2009. Observations were classified in three age strata: children and adolescents (10 to 18 years old), adults (19 to 59 years old) and elderly (60 years old or older). They were also identified according to the geographic regions or states where they live in: North, South, Northeast, Center-West, São Paulo state, and the group of Minas Gerais, Rio de Janeiro and Espírito Santo states. To estimate carotenoid intake in the diet, a database was built and food composition of these bioactive compounds were obtained, with priority, in a national database, and the distinct modes of preparation were considered. The ingestion of energy, macronutrients, vitamins, minerals and dietary fiber was analyzed as well, but according to food composition data from BIGS. The BMI was calculated and multiple regressions were fitted to data, controlling socioeconomic and geographic variables. Amidst the results, it was noted that the higher is the share of ultra-processed foods, expressed as energy intake, the lower is the age strata. BFP beneficiaries tend to obtain lower proportions of energy intake by these foods. In general, the ingestion of dietary fiber (except for men) and polyunsaturated fatty acids was considered low and the consumption of trans fatty acids was high. The amounts (average values) of vitamins E, A, D, folate, B1 (for elderly women) e B6 (for elderly men), calcium, potassium, magnesium and phosphorus (for children and adolescents) were evaluated as low. On the other hand, the sodium intake was expressively high. The main dietary sources of the majority of minerals were minimally processed or in natura foods, except for sodium and manganese. Processed foods and culinary preparations (without ultra-processed foods in their recipes) were important sources of vitamins C, D and B-vitamins, but of cholesterol, lipids and saturated fatty acids as well. The proportion of trans fatty acids obtained in ultra-processed foods was notable. Carotenoid intake in the diet did not fit into Prudent individual daily range intake, and the main sources of these phytochemicals were, beside fruits and vegetables, pasta prepared with tomato sauce (for lycopene) and soups (for ?-carotene and provitamin A carotenoids). No statistically significant effect from the share of energy obtained by foods, categorized into groups, was observed on BMI.

No description available.

The master thesis addresses the issue of cultivation of selected strains of carotenogenic yeasts on waste materials of the food industry using a laboratory bioreactor. Carotenogenic yeasts are able to produce highly valuable metabolites during cultivation, which are located predominantly in the lipid part of the cells. Particularly, they are carotenoids, ergosterol, coenzyme Q and fatty acids. The thesis is divided into two main parts, the theoretical part and the practical part. The theoretical part describes individual yeast strains, types of waste materials, produced metabolites and methods of their analysis. The experimental part deals with the processing of waste materials of the food industry, specifically animal fat, whey and spent coffee grounds into the form of substrates usable as nutrition sources for yeast cultivation. Furthermore, cultivations focused on the recovery of the monitored metabolites and their analysis by using HPLC/PDA and GC/FID assemblies were studied as well. The yeast strains Rhodotorula mucilaginosa (CCY 19-4-6), Rhodotorula kratochvilae (CCY 20-2-26), Rhodosporidium toruloides (CCY 062-002-001), Sporidiobolus pararoseus (CCY 19-9-6) a Cystofilobasidium macerans (CCY 10-1-2) were used in this work. As one of the best producing strains Sporidiobolus pararoseus (CCY 19-9-6) was found, which achieved very high productions of carotenoids, coenzyme Q and ergosterol.

Karotenoidy jsou přírodní pigmenty vyskytující se v mikroorganismech jako jsou řasy, kvasinky a sinice. Představují nejrozšířenější skupinu antioxidantů s významným biologickým účinkem. V současnosti vzrůstá zájem o karotenoidy vzhledem k jejich příznivým vlivům na lidské zdraví. Chlorofyly jsou zelená fotosyntetická barviva, která nacházejí uplatnění v potravinářství jako intenzivní zelená barviva. Koenzym Q je znám svým pozitivním vlivem pro správnou funkci řady orgánů v lidském těle. Ergosterol je nedílnou součástí membrán kvasinek a hub. Je to provitamin D2, který je důležitou součástí imunitního systému. Mikrobiální lipidy, nebo také ‚‚Single cell oils‘‘ jsou charakteristické vysokým obsahem zdraví prospěšných nenasycených mastných kyselin, které lze využít ve farmacii či kosmetice. Mikrobiální lipidy jsou dále studovány jako alternativa pro výrobu biopaliv. Dizertační práce byla zaměřena na studium a možnosti optimalizace produkce lipidů a lipidických látek vybranými kmeny karotenogenních kvasinek, mikrořas a sinic. V rámci práce byly testované kvasinky rodu Rhodotorula, Rhodosporidium, Cystofilobasidium a Sporidiobolus podrobené kultivacím na sérií médií s různými C/N poměry v rozsahu 13 až 100, obsahujících upravené odpadní substráty z potravinářského průmyslu. Vybrané kmeny byly poté kultivovány v bioreaktorech v médiu obsahujícím kombinaci odpadních substrátů. Kultivace mikrořas rodu Desmodesmus, Scenedesmus, Chlorella, Coccomyxa, Chlamydomonas, Botryococcus se zabývaly optimalizací jednotlivých komponent média a aplikací různých stresů s cílem navýšení produkce studovaných metabolitů. V rámci experimentů s extrémofilní mikrořasou Coccomyxa byly provedeny pilotní velkoobjemové kultivace v otevřených nádržích. V závěrečné části byl provedeny pilotní screeningové a velkoobjemové bioreaktorové experimenty zaměřené na možnosti kokultivace karotenogenních kvasinek a mikrořas. Testované kmeny kvasinek byly s rozdílnou úspěšností schopny utilizovat média obsahující hydrolyzované odpadní substráty. Nejlepším kmenem byl Sporidiobolus pararoseus, který na médiích dosahoval nejvyšších produkcí biomasy i sledovaných metabolitů. Z testovaných odpadních substrátů byla nejlepší kombinace odpadního fritovacího oleje a hydrolyzátu kávové sedliny. Úspěšná optimalizace složení hlavních komponent minerálního média vedla k zvýšené produkci studovaných metabolitů. Největší vliv měl optimální poměr P/N a aplikace oxidačního stresu. Nejlepších výsledků dosáhly mikrořasy rodu Desmodesmus a Scenedesmus. Velkoobjemové kultivace Coccomyxy onubensis potvrdily rezistenci kultury proti kontaminaci vnějšími vlivy a schopnost růstu za vysoké teploty a intenzity světelného záření. Kokultivační experimenty potvrdily schopnost symbiotického růstu kvasinek a mikrořas. Nejlepších výsledků dosahovaly všechny testované kvasinky s mikrořasami rodu Demsodesmus a Scenedesmus a v menší míře i rodu Coccomyxa.

This diploma thesis deals with the natural antioxidants present in cereals, especially in barley (Hordeum vulgare). A close attention is paid to the study of carotenoids determination was conducted. In the experimental part, the method of beta-carotene determination was optimized using high-performance liquid chromatography, diode array detector and mass detector (HPLC/DAD/APCI-MS). The method was used for the beta-carotene and lutein determination in the samples of barleycorn, malt and green barley. This method involves the sample saponification, extraction by diethylether, followed by separation on ODS Hypersil 250x4,6 mm, 5m column, using MTBE/MeOH (20:80) as mobile phase and spectrophotometric detection (450 nm). Quantitative analysis was implemented in the HPLC/DAD system. The MS detector was used for identification of analytes. A number of still unpublished data about the content of beta-carotene and lutein in several varieties of malting barley, malt and green barley are stated in this thesis. The highest content of beta-carotene was found in the green barley sample of variety Malz, harvested in first grow phase (8,49 mg/kg of the dry matter). The content of beta-carotene in barleycorn is relatively low (0,07-0,14 mg/kg of the dry matter). The content of beta-carotene is several times higher in the malt produced from barleycorn (0,24-0,56 mg/kg of the dry matter). The diploma thesis was implemented in the Research Institute of Brewing and Malting, Plc. in Brno.

Kvasinky žijú v neustále sa meniacom prostredí. Aby prežili tieto výkyvy ich okolitého prostredia, musia sa vedieť rýchlo a efektívne prispôsobiť novým podmienkam. Jedným z aspektov takejto bunkovej adaptácie je reorganizácia génovej expresie na program vyžadovaný pre rast v novom prostredí. Dôsledkom tejto reorganizácie genómu sú zmeny v metabolizme a fyziológií kvasiniek. Molekulárna odpoveď bunky určuje či sa organizmus adaptuje, prežije alebo zahynie. Predložená dizertačná práca sa zaoberá štúdiom vplyvu environmentálnych zmien na genóm a metabolóm vybraných karotenogénnych kvasiniek. Kvasinky boli kultivované jednak za optimálnych podmienok a jednak v oxidačnom a ozmotickom strese a na rôznych odpadových materiáloch (srvátke, zemiakovom odpade a pod.). V prítomnosti stresu bola pozorovaná zvýšená produkcia biologicky významných karotenoidov. Takáto obohatená biomasa môže nájsť svoje uplatnenie v biotechnologickom priemysle, napr. ako krmivo pre zvieratá. Možnosťou štúdia odozvy mikroorganizmov na environmentálny stres je aj príprava transformantov s deléciou vybraných génov a ich analýza. V ďalšej časti práce bola prevedená delécia vybraných génov kvasinky Schizosaccharomyces pombe. Zvolená technika je založená na knockoute konštruktov, ktoré obsahujú regióny homologické s deletovaným génom. Analýzou vytvorených transformantov boli identifikované proteíny potrebné pri meiotickej segregácií chromozómov.

The scope of thesis was the optimization of methods for the study of yeast and their metabolites using flow cytometry and fluorescence microscopy. Red yeasts are characterized by overproduction of carotenoids and lipids, which are used in food, pharmaceutical and feed industries. Currently, intensive research is being carried on to find appropriate microbiological alternatives for synthesis of these substances. Present thesis is focused on selected yeast genera: Rhodotorula, Sporobolomyces, Cystofilobasidium and strain Phaffia rhodozyma. Yeasts were cultivated on different nutrient media, in which glucose was used as a nutritional source, and also on glycerol and whey as waste material. In two strains - Cystofilobasidium macerans and Rhodotorula mucilaginosa growth characteristics were determined on a synthetic glucose production medium. All studied strains were able to use waste substrates as a source of nutrients. Some of the strains displayed increased production of carotenoids, and, additionally, in some cases also relatively high production of lipids. In classical cultivation in lipid and glucose medium supplemented with vitamins the best production characteristics displayed Rhodotorula glutinisstrain. In glycerol medium the highest amount of carotenoids and lipidic substances produced Sporobolomyces shibatanus strain. Strain Sporobolomyces roseus showed the best production characteristics on whey as the main source of carbon. The results show use of whey and glycerol seems like appropriate option for potential carbon source to cultivate carotenogenic yeasts and production of carotenoids and selected lipidic substances as products with higher added value. Further optimization of nutrient medium on the given substrates is needed for higher production of selected metabolites. Fluorescence microscopy and flow cytometry have proved to be suitable options for determination of the observed metabolites in the cells, their amount and viability.

This work is dealing with application of advanced fluorescence techniques for gaining knowledge about culture development during fermentation of red yeasts. Flow cytometry was used for auto-fluorescence measurement a carotenoids quantitation. It was resolved that while carotenoids are stored mainly in membranes the technique was feasible. If red yeast starts to accumulate carotenoids into lipid bodies mainly throughout the course of stationary phase, then the method starts to fail. Flow cytometric method using cell size measurement and light scatter for lipid quantitation was proved as applicable, too. However, it works only if cells are not starved. Individual calibration for each species is needed for elimination inter-species variations of intracellular structures. Fluorescence lifetime imaging microscopy was also used for studying of red yeast. Inherent ability to resolve different fluorescent species of the same molecule, which arise due to different molecular environment, helps with quantitation of cellular lipidic structures changes through the course of fermentation. Increase in the levels of carotenoids and/or rigidity of membranes was found as mechanism of protection during metabolic shifts, when intracellular content is vulnerable to damage.

PhD (Agric) (Food Science and Technology) / Department Food Science and Technology / In recent years, there has been a lot of interest in orange fleshed sweet potato (OFSP) [Ipomoea batatas (L.) Lam] cultivar, as a cheaper source of vitamin A. In Southern Africa, reports have shown that one in every three children has deficiency in vitamin A. This study investigated the variations in β-carotene (vitamin A precursor) content among selected OFSP cultivars grown in Limpopo Province, South Africa. In addition, the study investigated the effects of location on functional properties, total carotenoids and antioxidant profile of the sweet potato flour as well as their physicochemical, functional and nutritional properties. Four (4) sweet potato cultivars [Dagga, Bophelo, Impilo (orange fleshed) and Mvuvhelo (cream fleshed)] were obtained from two locations, namely, University of Venda (Univen) agricultural experimental farm and Tshiombo irrigation scheme (Tshiombo) and analysed for pasting, functional, physicochemical and nutritional properties. The sweet potato flours from these two locations were also analysed by computed tomographic (CT) scans for flour particle density. Mineral and microstructure of OFSP flours were analysed by scanning electron microscope (SEM). All measurements, except the tristimulus L* a* b* and other colour parameters from five replicates, were performed in triplicate. Statistical analysis was performed using a one-way analysis of variance and means were separated using Duncan’s multiple range test; P < 0.05 was considered to be statistically significant. Pearson’s correlation coefficients were used to determine the correlation among functional, physicochemical, nutritional and pasting properties of sweet potato flour. β-carotene content varied significantly between the two locations from 70.98 ± 0.8 μg/g (Tshiombo) to 86.09 ± 2.0 μg/g (Univen), among cultivars from 1.71 ± 0.0 μg/g (Mvuvhelo) to 201.50 ± 1.0 μg/g (Dagga) and among orange fleshed (Dagga, Bophelo and Impilo) flours from 28.38 ± 0.2 μg/g (Impilo) to 201.50 ± 1.0 μg/g (Dagga). There was a similar trend in the contents of α-carotene to that of β-carotene from the two locations, which ranged from 0.63 ± 0.0 mol/L (Tshiombo) to 1.01 ± 0.0 mol/L (Univen). Mvuvhelo had significantly the lowest α-carotene content (0.50 ± 0.0 mol/L) and Impilo the highest (1.28 ± 0.0 mol/L). The total carotenoids was highest for Impilo (7.56 μg/g) and lowest for Mvuvhelo (1.33 ± 0.1 μg/g) but did not vary significantly (P > 0.05) between ii the locations. The antioxidant activity, based on 2, 2-diphenyl-1picrylhydrazyl (DPPH) free radical scavenging activity, was significantly highest in Bophelo (63.37 ± 0.8 mMAAE ml-1) and lowest in Dagga (26.93 ± 1.4 mMAAE ml-1) flours. The ferric reducing antioxidant power (FRAP) varied significantly across the locations and among the cultivars and ranged from 14.45 ± 0.3 μMTE ml-1 (Tshiombo) to 17.40 ± 1.1 μMTE ml-1 (Univen). FRAP was significantly highest in Impilo (21.12 ± 2.1 μMTE ml-1) and lowest in Mvuvhelo (8.16 ± 2.0 μMTE ml-1). Total carotenoid content positively correlated with DPPH (0.486*), FRAP (0.830**), β-carotene (0.370*), and α-carotene (0.424*). The antioxidant content and the radical scavenging activity were significantly correlated (0.563**). Vitamin A content was significantly lowest (6.88 ± 0.38 μg/g retinol) in Dagga flour and highest (7.97 ± 0.25 μg/g) in Impilo flour. Protein content varied significantly across the two locations and ranged from 4.23% (Tshiombo) to 7.16% (Univen). Dagga had significantly the lowest (3.47%) protein content while Impilo had the highest (7.53%). The fat content of the flours varied significantly between the two locations ranging from 0.63% (Tshiombo) to 1.01% (Univen). The protein content was positively correlated 0.594** and 0.421* to vitamin A and fat contents respectively. The Bophelo colour luminosity was significantly lower (L* 76.2) than the other two OFSP, Dagga (L* 83.51) and Impilo (L* 82.07). Bophelo a* (14.09) also differed significantly across all sweet potato cultivars. All cultivars differed significantly in b* values. Colour intensity (ΔE*) ranged from 15.87 to 38.48 for Mvuvhelo and Bophelo, respectively. Chroma ranged from 87.52 to 84.95 for Dagga and Mvuvhelo respectively. Total starch content was significantly different in all sweet potato cultivars and ranged from 244.07 μg/100 g (Bophelo) to 325.04 mg/g (Dagga). Resistant starch differed significantly in all sweet potato cultivars ranging from 1.21 μg/100 g dwb (Bophelo) to 7.07 μg/100 g dwb (Impilo). Ash content was significantly different in all cultivars and ranged from 3.17% (Dagga) to 3.79% (Bophelo). Water holding capacity (WHC) varied significantly across the two locations and ranged from 1.44 g H2O/g DM (Tshiombo) to 1.72 g H2O/g DM (Univen). Bophelo had significantly the lowest (1.27 g H2O/g DM) WHC and Impilo the highest (1.99 g H2O/g DM). The ash content negatively correlated to total starch (-0.928**) but positively iii correlated to WHC (0.654**). Peak viscosity differed significantly across all cultivars under study and ranged from 126.54 RVU (Bophelo) to 302.36 RVU. (Dagga). There was significant difference in trough viscosity across all cultivars ranging from 55.97 RVU (Impilo) to 280.78 RVU (Dagga). There were significant differences in the final viscosity across all cultivars ranging from 78.99 RVU (Impilo) to 319.26 (Dagga). Peak time viscosity varied significantly across all cultivars ranging from 3.87 min (Impilo) to 8.47 min. (Bophelo). Dagga cultivar had significantly the highest pasting temperature (94.16oC) and Bophelo the lowest (77.75oC). The setback viscosity was significantly highest 51.10 RVU (Mvuvhelo) and lowest 23.01 RVU (Impilo). All cultivars from the two locations consistently showed high potassium content ranging from 0.46% (Impilo) to 1.38% (Dagga) as compared to other minerals such as magnesium, calcium and chlorine which ranged from 0.16% (Impilo) to 0.34%. (Dagga). The CT scans revealed that there was a possibility of evaluating the effect of location on the density of granules of sweet potato flour and also the inherent differences in granular distribution of various sweet potato cultivars. SEM revealed high amounts of potassium, magnesium and chlorine. A profile of physicochemical and functional properties of flour of some of the OFSP cultivars produced in Limpopo province, South Africa has been drawn. This study also highlights the nutritional quality of the flour from four sweet potato cultivars and provides a ranking of flour to help the producers in the selection process. Bophelo flour was ranked the highest in terms of β- and, α-carotenes, total carotenoids and antioxidant capacity while Impilo was ranked highest in terms of functional properties and ash content. This study has highlighted significant differences in a number of parameters measured among the sweet potato cultivars. Therefore, in order to derive the maximum benefit from aIn recent years, there has been a lot of interest in orange fleshed sweet potato (OFSP) [Ipomoea batatas (L.) Lam] cultivar, as a cheaper source of vitamin A. In Southern Africa, reports have shown that one in every three children has deficiency in vitamin A. This study investigated the variations in β-carotene (vitamin A precursor) content among selected OFSP cultivars grown in Limpopo Province, South Africa. In addition, the study investigated the effects of location on functional properties, total carotenoids and antioxidant profile of the sweet potato flour as well as their physicochemical, functional and nutritional properties. Four (4) sweet potato cultivars [Dagga, Bophelo, Impilo (orange fleshed) and Mvuvhelo (cream fleshed)] were obtained from two locations, namely, University of Venda (Univen) agricultural experimental farm and Tshiombo irrigation scheme (Tshiombo) and analysed for pasting, functional, physicochemical and nutritional properties. The sweet potato flours from these two locations were also analysed by computed tomographic (CT) scans for flour particle density. Mineral and microstructure of OFSP flours were analysed by scanning electron microscope (SEM). All measurements, except the tristimulus L* a* b* and other colour parameters from five replicates, were performed in triplicate. Statistical analysis was performed using a one-way analysis of variance and means were separated using Duncan’s multiple range test; P < 0.05 was considered to be statistically significant. Pearson’s correlation coefficients were used to determine the correlation among functional, physicochemical, nutritional and pasting properties of sweet potato flour. β-carotene content varied significantly between the two locations from 70.98 ± 0.8 μg/g (Tshiombo) to 86.09 ± 2.0 μg/g (Univen), among cultivars from 1.71 ± 0.0 μg/g (Mvuvhelo) to 201.50 ± 1.0 μg/g (Dagga) and among orange fleshed (Dagga, Bophelo and Impilo) flours from 28.38 ± 0.2 μg/g (Impilo) to 201.50 ± 1.0 μg/g (Dagga). There was a similar trend in the contents of α-carotene to that of β-carotene from the two locations, which ranged from 0.63 ± 0.0 mol/L (Tshiombo) to 1.01 ± 0.0 mol/L (Univen). Mvuvhelo had significantly the lowest α-carotene content (0.50 ± 0.0 mol/L) and Impilo the highest (1.28 ± 0.0 mol/L). The total carotenoids was highest for Impilo (7.56 μg/g) and lowest for Mvuvhelo (1.33 ± 0.1 μg/g) but did not vary significantly (P > 0.05) between ii the locations. The antioxidant activity, based on 2, 2-diphenyl-1picrylhydrazyl (DPPH) free radical scavenging activity, was significantly highest in Bophelo (63.37 ± 0.8 mMAAE ml-1) and lowest in Dagga (26.93 ± 1.4 mMAAE ml-1) flours. The ferric reducing antioxidant power (FRAP) varied significantly across the locations and among the cultivars and ranged from 14.45 ± 0.3 μMTE ml-1 (Tshiombo) to 17.40 ± 1.1 μMTE ml-1 (Univen). FRAP was significantly highest in Impilo (21.12 ± 2.1 μMTE ml-1) and lowest in Mvuvhelo (8.16 ± 2.0 μMTE ml-1). Total carotenoid content positively correlated with DPPH (0.486*), FRAP (0.830**), β-carotene (0.370*), and α-carotene (0.424*). The antioxidant content and the radical scavenging activity were significantly correlated (0.563**). Vitamin A content was significantly lowest (6.88 ± 0.38 μg/g retinol) in Dagga flour and highest (7.97 ± 0.25 μg/g) in Impilo flour. Protein content varied significantly across the two locations and ranged from 4.23% (Tshiombo) to 7.16% (Univen). Dagga had significantly the lowest (3.47%) protein content while Impilo had the highest (7.53%). The fat content of the flours varied significantly between the two locations ranging from 0.63% (Tshiombo) to 1.01% (Univen). The protein content was positively correlated 0.594** and 0.421* to vitamin A and fat contents respectively. The Bophelo colour luminosity was significantly lower (L* 76.2) than the other two OFSP, Dagga (L* 83.51) and Impilo (L* 82.07). Bophelo a* (14.09) also differed significantly across all sweet potato cultivars. All cultivars differed significantly in b* values. Colour intensity (ΔE*) ranged from 15.87 to 38.48 for Mvuvhelo and Bophelo, respectively. Chroma ranged from 87.52 to 84.95 for Dagga and Mvuvhelo respectively. Total starch content was significantly different in all sweet potato cultivars and ranged from 244.07 μg/100 g (Bophelo) to 325.04 mg/g (Dagga). Resistant starch differed significantly in all sweet potato cultivars ranging from 1.21 μg/100 g dwb (Bophelo) to 7.07 μg/100 g dwb (Impilo). Ash content was significantly different in all cultivars and ranged from 3.17% (Dagga) to 3.79% (Bophelo). Water holding capacity (WHC) varied significantly across the two locations and ranged from 1.44 g H2O/g DM (Tshiombo) to 1.72 g H2O/g DM (Univen). Bophelo had significantly the lowest (1.27 g H2O/g DM) WHC and Impilo the highest (1.99 g H2O/g DM). The ash content negatively correlated to total starch (-0.928**) but positively iii correlated to WHC (0.654**). Peak viscosity differed significantly across all cultivars under study and ranged from 126.54 RVU (Bophelo) to 302.36 RVU. (Dagga). There was significant difference in trough viscosity across all cultivars ranging from 55.97 RVU (Impilo) to 280.78 RVU (Dagga). There were significant differences in the final viscosity across all cultivars ranging from 78.99 RVU (Impilo) to 319.26 (Dagga). Peak time viscosity varied significantly across all cultivars ranging from 3.87 min (Impilo) to 8.47 min. (Bophelo). Dagga cultivar had significantly the highest pasting temperature (94.16oC) and Bophelo the lowest (77.75oC). The setback viscosity was significantly highest 51.10 RVU (Mvuvhelo) and lowest 23.01 RVU (Impilo). All cultivars from the two locations consistently showed high potassium content ranging from 0.46% (Impilo) to 1.38% (Dagga) as compared to other minerals such as magnesium, calcium and chlorine which ranged from 0.16% (Impilo) to 0.34%. (Dagga). The CT scans revealed that there was a possibility of evaluating the effect of location on the density of granules of sweet potato flour and also the inherent differences in granular distribution of various sweet potato cultivars. SEM revealed high amounts of potassium, magnesium and chlorine. A profile of physicochemical and functional properties of flour of some of the OFSP cultivars produced in Limpopo province, South Africa has been drawn. This study also highlights the nutritional quality of the flour from four sweet potato cultivars and provides a ranking of flour to help the producers in the selection process. Bophelo flour was ranked the highest in terms of β- and, α-carotenes, total carotenoids and antioxidant capacity while Impilo was ranked highest in terms of functional properties and ash content. This study has highlighted significant differences in a number of parameters measured among the sweet potato cultivars. Therefore, in order to derive the maximum benefit from a given cultivar careful selection of sweet potato cultivars would be necessary.