Submitted in fulfillment of the requirements of the Degree of Master of Technology: Biotechnology, Durban University of Technology, 2011. / Riboflavin (vitamin B2), an essential water-soluble vitamin is commercially produced because it cannot be synthesized by vertebrates. Although this vitamin is produced chemically, bioproduction is a better option since it is more economical, requires less energy, produces less waste and can use renewable sources. In this study we investigated spent oil from the food and motor industries as alternative cheap carbon sources for the bioproduction of this vitamin. Commercial fungal strains namely; Eremothecium gossypii ATCC 10895, Eremothecium gossypii CBS 109.51, Eremothecium ashbyi CBS 206.58 and the yeast, Candida famata ATCC 20850, as well as a laboratory mutated Eremothecium gossypii EMS 30/1 strain were used. Statistical experimental design using a series of fractional factorial experimental designs was used to optimize the effect of yeast extract, peptone, malt extract, K2HPO4 and MgSO4.7H2O to supplement the used oils for optimum riboflavin production. Response surface methodology based on central composite experimental designs was then applied and together with the point predictions made, production media for both substrates were further optimized. The optimized conditions were then tested with laboratory experiments. Results showed that mutant E. gossypii EMS 30/1 produced the most riboflavin in spent motor oil (20.45 mg.l-1) while Candida famata ATCC 20850 produced the highest concentration (16.99 mg.l-1) in spent vegetable oil. With these strains and using the experimental designs from the fractional factorial experiments, supplemented spent motor and spent vegetable oils produced 66.27 mg.l-1 and 72.50 mg.l-1 riboflavin, respectively. The central composite optimization results showed that 0.18 g.l-1 and 0.45 g.l-1 K2HPO4 and 12.5 g.l-1 malt extract increased the production to 91.88 mg.l-1 and 78.68 mg.l-1 in spent vegetable oil and motor oil respectively. A point prediction from the response surface methodology was used to validate these and it was found that 103.59 mg.l-1 riboflavin was produced by mutant E. gossypii EMS 30/1 using 2.5 g.l-1 yeast extract, 0.5 g.l-1 peptone, 12.5 g.l-1 malt extract, 0.18 g.l-1 K2HPO4 and 0.3 g.l-1 MgSO4.7H2O. After optimizing K2HPO4 in a one-factor-at-a-time experiment, 82.75 mg.l-1 riboflavin was produced by C. famataon v SVO using 6.5 g.l-1 peptone, 12.5 g.l-1 malt extract 0.15 g.l-1 K2HPO4 and 1.75 g.l-1 MgSO4.7H2O. This is a 5.08 and 4.87 fold increase respectively when compared to spent oil prior to optimization. This shows that spent motor oil and mutant E. gossypii produces 103.59 mg.l-1 riboflavin while spent vegetable oil and C. famata produces 82.75 mg.l-1 riboflavin. Hence, E. gossypii can be used to generate riboflavin using spent motor oil and C. famata, using spent vegetable oil.

No description available.

Em um delineamento em Quadrado Latino 4X4 balanceado, foram utilizados quatro potros, filhos do mesmo garanhão, com idade entre 10 e 12 meses e peso médio de 270 kg (dp ± 9,80 Kg). Foram analisados os efeitos, por regressão simples polinomial, da inclusão dos níveis de 5, 10, 15 e 20 % de óleo de soja, no concentrado, sobre aceitabilidade, coeficiente de digestibilidade aparente da matéria seca (CDAMS), matéria orgânica (CDAMO), proteína bruta (CDAPB), extrato etéreo (CDAEE), fibra insolúvel em detergente neutro (CDAFDN), em detergente ácido (CDAFDA) e sobre a concentração plasmática de colesterol total (COL) e suas frações nas lipoproteína de densidade muito baixa (VLDL-C), lipoproteína de densidade baixa (LDL-C), lipoproteína de densidade alta (HDL-C) e triglicérides totais (TRG). O aumento do nível de inclusão de óleo afetou (p<0,05) o CDAMO, CDAFDN e CDAFDA, apresentando uma resposta quadrática, com diminuição da digestibilidade após o valor esperado de 10,7%, 9,5% e 10,5% EE na dieta, respectivamente. Observou-se resposta linear (p<0,05) dos tratamentos sobre a concentração plasmática de colesterol e LDL-C, apresentando diminuição 0,65 mg/dL de colesterol e 0,58 mg/dL de LDL-C para cada 1% de aumento no EE no concentrado. A inclusão de óleo de soja afetou a digestibilidade da dieta, principalmente na fração parede celular e diminuiu a concentração plasmática de colesterol e HDL-C. / In a balanced 4x4 Latin Square design, 04 foals from the same stallion were used. They aged between 10 and 12 months and their average weight was 270±9.80 kg. The effects of soybean oil inclusion at the concentrated on acceptability, coefficient of apparent digestibility to dry matter (CADAMS), organic matter (CADOM), crude protein (CADCP), ethereal extract (CADEE), neutral detergent fiber (CADNDF), acid detergent (CADADF) and the plasma concentrations of total cholesterol (COL) and the fractions in Very Low Density Lipoprotein (VLDL - C), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C) and total triglycerides (TRG), at the following levels of 5, 10, 15 and 20%, were analyzed by simple polynomial regression. Increase in the level of oil inclusion affected (P<0.05) CADOM, CADNDF and CADADF, showing a quadratic response. For those parameters, digestibility was decreased after inclusion of 10.7%, 9.5% and 10.5 of EE% in the diet, respectively. There was a linear response (P<0.05) to the treatments on the cholesterol plasma concentration and LDL-C; each 1% of increase in EE on the diet caused a decreased of 0.65 mg/dL on cholesterol and 0.58 mg / dL on LDL-C. The inclusion of soybean oil affected the digestibility of the diet, mainly on cell wall fraction, and decreased the concentration of plasma cholesterol and HDL-C.

Theobroma cacao é o nome científico do cacau, sugerido no século XVIII por Linné. Porém a história do chocolate se inicia bem antes com as civilizações mesoamericanas Asteca e Maia e, ainda a recém citada Olmeca, entre outros grupos. Os Olmecas, cultura existente a três milênios atrás, foram possivelmente os primeiros a utilizar o chocolate. Os Astecas usavam o chocolate para representar o sangue, um símbolo poderoso, e como moeda. Coube aos espanhóis difundir para o resto do mundo, a partir do século XVI, o chocolate ou \"tchocolath\" , bebida amarga e apimentada, na qual inicialmente diminuiu-se a proporção de especiarias e acrescentou-se mel ou açúcar. Atualmente o chocolate é um produto extremamente consumido e cujas propriedades ainda estão sendo descobertas. Foram analisados chocolates \"tipo cobertura\" disponíveis no mercado brasileiro, com base em suas propriedades químicas e físicas, com ênfase no estudo de reologia. O estudo instrumental da textura de chocolates é o principal método para avaliação do processo de fabricação e das matérias primas utilizadas. A porcentagem de manteiga de cacau e de gorduras sucedâneas é de especial importância. Também foram avaliadas a influência da adição de parafina nesses chocolates, bem como a compatibilidade de misturas entre chocolates fabricados com manteiga de cacau e \"chocolates\" fabricados com gorduras hidrogenadas. Pela composição em ácidos graxos identificou-se o tipo de gordura utilizada nas coberturas: láurica (Harald branca e ao leite); não-Iáurica (GDT-L9, GDT -BL); mistura láuricalnão-Iáurica (Evelyn branca, MDT -L); manteiga de cacau (Vitória branca e ao leite; Garoto branca, ao leite e meio amarga; Lacta e Dan Top branca). Os diagramas C50 x C54 e o diagrama ternário (POP-SOS-POS) forneceram informações sobre os tipos de gorduras empregadas. O diagrama de iso-dureza apontou a formação de eutético nas misturas entre coberturas Garoto e Harald ao leite, principalmente na proporção 50:50. Os resultados da análise de textura mostraram grande variabilidade em todos os parâmetros, fornecendo um perfil de comportamento para as coberturas. A retemperagem alterou o parâmetro de dureza nas diferentes temperaturas. Existiu diferença entre as amostras retemperadas com e sem parafina. O viscosímetro Brookfield-L V juntamente com programa de computador forneceu resultados satisfatórios para análise de chocolate, sendo um método prático e de baixo custo. A viscosidade não variou linearmente com o conteúdo de gordura. A curva de resfriamento pode prestar-se à identificação do tipo de gordura utilizada na produção de chocolate. / Theobroma cacao is the scientific name of the cocoa, suggested in the XVIII century by Linné. However, the history of the chocolate begins before Aztecs and Mayans Mesoamerican civilizations, and the new mentioned Olmecs, among other groups. The Olmecs, a culture existing some three millennia ago, were possibly the first ones to use the chocolate. In some forms, the Aztecs used the chocolate to represent blood, a symbol visually potent, and uniformly used as currency among Mesoamerican cultures. From XVI century, the Spanishies diffused the chocolate other \"tchocolath\" to the rest of the World, adding honey or sugar to the spicy drink. Nowadays, chocolate is an extremely consumed product and whose properties are still being discovered. Physicochemical properties and rheological studies of the couverture chocolate available at the Brazilian market were analysed. Instrumental study of texture characteristics is a principal requiriment for evaluating manufacturing process and raw materiais used. The cocoa butter percentage and replacement fats are of special importance. The addition of paraffin also was eva I uated , as well as the compatibility of the mixtures among couvertures with cocoa butter and couvertures with replacement fats. The fats of the couvertures were identified by the fatty acids composition method: lauric fat (Harald white and milk couvertures); non lauric fat (GDTL9 and GDT -BL couvertures); mixture lauriclnon lauric fats (Evelyn white couvertures and MDT-L couverture); cocoa butter (Vitória white and milk couvertures; Garoto white, milk and bitter couvertures; Lacta milk couverture and Dan Top white couverture). Temary (POP-POS-SOS) and C50xC54 diagrams provided informations about the types of the fat used in the couvertures. formulation. Iso-hardness diagram showed the eutectic formation at the couverture mixtures (Garoto and Harald milk couvertures), mainly in the proportion 50:50. Results of the texture evaluation showed large variability of ali parameters, providing a behaviour profile of the couvertures. Manual tempering modified the hardness at different temperatures. There was difference among with and without paraffin manual tempering. Brookfield-L V viscosimeter and the computer program provided satisfactory results to the chocolate analyses, being a practical and low cost method. Viscosity didn\'t vary linearly with fat content. The cooling curve may be used as a identification method of the fat type used in the chocolate products.

Muitas famílias não têm tempo de preparar bolos caseiros e acabam optando pela praticidade de comprar produtos prontos. A atitude dos consumidores, em relação aos problemas de saúde que podem advir do consumo de alimentos com alto teor de gorduras, é de consumir alimentos formulados de maneira que apresentem menores teores, mas com as mesmas características sensoriais dos produtos originais. O objetivo deste estudo foi determinar o efeito da substituição de gordura vegetal hidrogenada por outros lipídeos (gordura de palma, óleo de soja, óleo de castanha do Brasil, óleo de coco) e por extrato de aveia em formulações de bolos. Foram elaboradas nove formulações contendo farinha de trigo, açúcar, ovo em pó, gordura, água, leite em pó integral, emulsificante, fermento químico e sal, substituindo-se a gordura vegetal hidrogenada pelos diferentes tipos de lipídeos e extrato de aveia. Formulações: (controle) gordura vegetal hidrogenada (GVH) - 100%; (1): gordura de palma - 100%; (2): óleo de soja - 100%; (3): óleo de castanha do Brasil - 100%; (4): óleo de coco - 100%; (5): extrato de aveia - 100%; (6): GVH - 50% + óleo de castanha do Brasil - 50%; (7): GVH - 50% + óleo de coco - 50%; (8): GVH - 50% + extrato de aveia - 50%. Através das análises de textura com probes back extrusion e de compressão (TPA-análise do perfil de textura) pode-se avaliar, respectivamente, o comportamento das massas de bolos e o shelf-life dos produtos finais durante seis dias de armazenamento. Foram feitas avaliações de volume específico, densidade, porosidade, composição centesimal e atividade de água - aw. A análise sensorial com 60 provadores foi realizada utilizando-se as formulações controle, óleo de coco, óleo de castanha do Brasil e extrato de aveia de acordo com a escala hedônica (9 pontos) e intenção de compra. A análise de textura (back extrusion) apontou diferentes comportamentos reológicos, embora todas as formulações caracterizaram-se como fluido dilatante (n>1). O resultado do shelf-life mostrou que o bolo produzido com extrato de aveia obteve melhores características de qualidade. O bolo produzido com GVH apresentou maior volume (2,65 mL/g), menor densidade (0,39 g/mL)e maior incorporação de ar (16,45 mm2). A análise de cor apontou que o bolo elaborado com GVH + óleo de coco apresentou-se mais amarelado (35,94) e o bolo com GVH + extrato de aveia com maior brilho (75,27). A composição centesimal mostrou as variações obtidas de acordo com a substituição de gordura por extrato de aveia e o menor valor calórico (257,62 kcal) para este produto. O resultado de aw mostrou maior valor para a formulação com extrato de aveia (0,94), sendo esperado devido ao maior conteúdo de água da formulação. A análise sensorial, através da avaliação de painel não treinado, indicou que o bolo elaborado com óleo de coco obteve a maior aceitação e, consequentemente, a maior intenção de compra, entretanto, apresentou pouca diferença em relação ao bolo controle. Em geral, os resultados mostraram ótimo padrão de qualidade dos bolos elaborados com a substituição da gordura vegetal hidrogenada, podendo-se assim, obter produtos com outras opções de ingredientes e com agregação de valor nutricional. / Many families do not have time to prepare homemade cakes and usually opt for the convenience of buying ready products. Consumer\'s attitudes regarding health issues, that may arise from the consumption of foods high in fat, is to consume foods that have formulated so low in fat, but with the same sensory characteristics of the original products. The purpose of this study was to determine the effect of replacing hydrogenated vegetable fat for other lipids (fat palm, soybean oil, Brazil nut oil, coconut oil) and oat extract in cake formulations. Nine formulations containing flour, sugar, egg powder, fat, water, whole milk powder, emulsifier, baking powder, and salt were elaborated by replacing the hydrogenated vegetable fat for different types of lipids and oat extract. Formulations: (control) hydrogenated vegetable fat (GVH) - 100%; (1): palm fat - 100%; (2) soybean oil - 100%; (3): Brazil nut oil - 100%; (4) coconut oil - 100%; (5): oat extract - 100%; (6): GVH - 50% + nut oil from Brazil - 50%; (7) GVH - 50% Coconut oil + - 50%; (8): GVH - 50% + oat extract - 50%. The behavior of cakes batters and shelf life of the final product during six days of storage were assessed through the texture analysis with probes back extrusion and compression (TPA-texture profile analysis), respectively. The evaluation of specific volume, density, porosity, chemical composition and water activity - aw was made. Sensory analysis was performed with 60 tasters using the control formulations, coconut oil, Brazil nut oil l and oat extract according to the hedonic scale (9 points) and purchase intent. Texture analysis (back extrusion) showed different rheological behaviors, although all formulations were characterized as a dilatant fluid (n> 1). The result of the shelf-life showed that the cake made with oat extract produced better quality characteristics. The cake produced with GVH showed higher volume (2,65 mL/g), lower density (0,39 g/mL) and greater incorporation of air (16,45 mm2). The color analysis showed that the cake made with coconut oil + GVH presented more yellowness (35,94) and cake with GVH + oat extract presented higher brightness (75,27). The chemical composition showed variations obtained in accordance with the substitution of fat for oat extract and lower caloric value (257,62 kcal) for this product. The result showed higher aw value (0,94) for the formulation with oat extract, it is expected due to the higher water content of the formulation. The sensory analysis, through evaluating untrained panel, indicated that the cake prepared with coconut oil had the highest acceptance and, consequently, the higher purchase intention, although it presented little difference from the control cake. In general, the results showed great standard of quality cakes prepared by replacing the hydrogenated vegetable fat, leading to products with other options of ingredients and with added nutritional value.

Theobroma cacao é o nome científico do cacau, sugerido no século XVIII por Linné. Porém a história do chocolate se inicia bem antes com as civilizações mesoamericanas Asteca e Maia e, ainda a recém citada Olmeca, entre outros grupos. Os Olmecas, cultura existente a três milênios atrás, foram possivelmente os primeiros a utilizar o chocolate. Os Astecas usavam o chocolate para representar o sangue, um símbolo poderoso, e como moeda. Coube aos espanhóis difundir para o resto do mundo, a partir do século XVI, o chocolate ou \"tchocolath\" , bebida amarga e apimentada, na qual inicialmente diminuiu-se a proporção de especiarias e acrescentou-se mel ou açúcar. Atualmente o chocolate é um produto extremamente consumido e cujas propriedades ainda estão sendo descobertas. Foram analisados chocolates \"tipo cobertura\" disponíveis no mercado brasileiro, com base em suas propriedades químicas e físicas, com ênfase no estudo de reologia. O estudo instrumental da textura de chocolates é o principal método para avaliação do processo de fabricação e das matérias primas utilizadas. A porcentagem de manteiga de cacau e de gorduras sucedâneas é de especial importância. Também foram avaliadas a influência da adição de parafina nesses chocolates, bem como a compatibilidade de misturas entre chocolates fabricados com manteiga de cacau e \"chocolates\" fabricados com gorduras hidrogenadas. Pela composição em ácidos graxos identificou-se o tipo de gordura utilizada nas coberturas: láurica (Harald branca e ao leite); não-Iáurica (GDT-L9, GDT -BL); mistura láuricalnão-Iáurica (Evelyn branca, MDT -L); manteiga de cacau (Vitória branca e ao leite; Garoto branca, ao leite e meio amarga; Lacta e Dan Top branca). Os diagramas C50 x C54 e o diagrama ternário (POP-SOS-POS) forneceram informações sobre os tipos de gorduras empregadas. O diagrama de iso-dureza apontou a formação de eutético nas misturas entre coberturas Garoto e Harald ao leite, principalmente na proporção 50:50. Os resultados da análise de textura mostraram grande variabilidade em todos os parâmetros, fornecendo um perfil de comportamento para as coberturas. A retemperagem alterou o parâmetro de dureza nas diferentes temperaturas. Existiu diferença entre as amostras retemperadas com e sem parafina. O viscosímetro Brookfield-L V juntamente com programa de computador forneceu resultados satisfatórios para análise de chocolate, sendo um método prático e de baixo custo. A viscosidade não variou linearmente com o conteúdo de gordura. A curva de resfriamento pode prestar-se à identificação do tipo de gordura utilizada na produção de chocolate. / Theobroma cacao is the scientific name of the cocoa, suggested in the XVIII century by Linné. However, the history of the chocolate begins before Aztecs and Mayans Mesoamerican civilizations, and the new mentioned Olmecs, among other groups. The Olmecs, a culture existing some three millennia ago, were possibly the first ones to use the chocolate. In some forms, the Aztecs used the chocolate to represent blood, a symbol visually potent, and uniformly used as currency among Mesoamerican cultures. From XVI century, the Spanishies diffused the chocolate other \"tchocolath\" to the rest of the World, adding honey or sugar to the spicy drink. Nowadays, chocolate is an extremely consumed product and whose properties are still being discovered. Physicochemical properties and rheological studies of the couverture chocolate available at the Brazilian market were analysed. Instrumental study of texture characteristics is a principal requiriment for evaluating manufacturing process and raw materiais used. The cocoa butter percentage and replacement fats are of special importance. The addition of paraffin also was eva I uated , as well as the compatibility of the mixtures among couvertures with cocoa butter and couvertures with replacement fats. The fats of the couvertures were identified by the fatty acids composition method: lauric fat (Harald white and milk couvertures); non lauric fat (GDTL9 and GDT -BL couvertures); mixture lauriclnon lauric fats (Evelyn white couvertures and MDT-L couverture); cocoa butter (Vitória white and milk couvertures; Garoto white, milk and bitter couvertures; Lacta milk couverture and Dan Top white couverture). Temary (POP-POS-SOS) and C50xC54 diagrams provided informations about the types of the fat used in the couvertures. formulation. Iso-hardness diagram showed the eutectic formation at the couverture mixtures (Garoto and Harald milk couvertures), mainly in the proportion 50:50. Results of the texture evaluation showed large variability of ali parameters, providing a behaviour profile of the couvertures. Manual tempering modified the hardness at different temperatures. There was difference among with and without paraffin manual tempering. Brookfield-L V viscosimeter and the computer program provided satisfactory results to the chocolate analyses, being a practical and low cost method. Viscosity didn\'t vary linearly with fat content. The cooling curve may be used as a identification method of the fat type used in the chocolate products.

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Thesis (Master of Applied Sciences in Chemistry)--Cape Peninsula University of Technology, 2018. / The high demand of omega-3 fish oil nutraceuticals (dietary supplements) is due to the numerous health benefits contributed by the polyunsaturated fatty acids (PUFA’s). The nutraceutical industry is required to follow good manufacturing practice (GMP) standards in order to ensure label claims and prevent adulteration. It is vital that the quality control (QC) procedures will be able to detect adulterated products. It is thus necessary to ensure the analytical techniques are adequate by using validated methods. The qualification or identification of natural fish oils is a difficult task due to overlapping concentration ranges of PUFA’s and other similar properties. Gas chromatography (GC) is the prescribed technique in the nutraceutical industry for analysis of omega-3 fatty acids, but it is time-consuming and costly. Near infrared (NIR) spectroscopy is a rapid and cost-effective technique that can replace the prescribed method if proven equivalent, through validation according to pharmaceutical criteria. In this study, NIR spectroscopy in combination with chemometrics was considered as an alternative method to GC, to identify various commercial fish oils and to quantify the PUFA’s. Identification methods were developed for nine commercial omega-3 fish oils using spectral libraries. Quantitative NIR methods were developed for arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) in fish oils expressed as mg.g-1 as well as percentage (%) area using partial least squares (PLS) regression and independent validation by superimposing datasets with mutual properties. Based on the statistics in terms of SEC, R2, SEP and r of the PUFA models, the NIR method was equivalent to the prescribed GC methods and precision results obtained were within the prescribed criteria. NIR spectroscopy and chemometrics can be used for conclusive identification and quantification of omega-3 fish oils, thereby minimizing the risk of adulteration. The method also complied with the prescribed pharmaceutical method validation criteria; therefore, was demonstrated as an alternative method to GC for the nutraceutical industry.

No description available.

This thesis investigates whether fats, akin to other taste stimuli, exhibit sensory properties such as mixture interactions. In order to determine gustatory, rather than tactile or olfactory effects, viscosity-controlled emulsions of deodorised oils were used as the base to which taste stimuli were incorporated and presented to a panel of trained assessors. In preliminary qualitative assessments, panellists described the 10% olive oil emulsion as saltier, stronger, fattier and having a more lingering aftertaste than the non-oil control, suggesting that oil modulates taste duration as well influencing taste intensity and/or perceived quality. Panellists were unable to rate the oil/fat taste per se with any degree of certainty hence further experiments examined the effect of oil on the perception of taste mixtures. In mixture interaction experiments, the addition of oil did not result in mixture suppression or enhancement for sweet, salty, sour or bitter while it significantly enhanced umami. To determine the locus of interaction, when MSG and oil were presented to each side of the tongue separately, the enhancement effect disappeared indicating a peripheral mechanism of interaction, similar to the attenuation of chilli burn by oil. In contrast, suprathreshold sucrose sweetness was enhanced by the contralateral presentation of oil, indicating sensory processing at a higher locus. Furthermore, the addition of oil significantly reduced bitterness in a caffeine-MSG mixture. Since earlier experiments did not indicate any interaction between oil and bitterness, the decrease in the perceived bitterness of this binary mixture is attributed to an increase in umami which is likely to have suppressed bitterness, the perceptually dominant component in this mixture. These findings suggest a gustatory role for fats in modulating the taste profile of mixtures, in particular, enhancing total taste intensity, prolonging taste duration, and enhancing umami. A taste receptor-based model of fat perception provides for an orosensory mechanism capable of signalling the arrival of the most energy-dense nutrient, essential fatty acids and fat-soluble vitamins. The chemosensory signal may also be the basis for hedonic responses with subsequent implications for intake.