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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Productivity and malnutrition elements in local and exotic Amaranthus cultivars

Makhado, Mashudu Viginia January 2021 (has links)
Thesis(M.Sc. Agricultural Management (Horticulture)) -- University of Limpopo, 2021 / Amaranthus species, with their adaptability to grow under various agro-ecologies and soil types, have gained considerable attention in food security due to their high nutritional content. However, various Amaranthus species are host to the root-knot (Meloidogyne species) nematodes, with limited information on how the pest could affect the nutritional composition of the crop. In other crops, infestation with Meloidogyne species have deleterious effects on accumulation of certain essential mineral nutrient elements. However, the influence of Meloidogyne species on essential mineral nutrient elements had not been documented on Amaranthus. The objectives of the study, therefore, were to determine the influence of infestation by Meloidogyne species on growth and accumulation of selected malnutrition elements in four exotic Amaranthus relative to the local cultivar under both greenhouse and field conditions. In the greenhouse study, hardened-off seedlings were transplanted into 20-cm diameter plastic pots containing a steam-pasteurised growing mixture. The 5 × 2 factorial experiments were arranged in a randomised complete block design, with five replications. The first and second factors were five Amaranthus cultivars and two Meloidogyne species, namely, M. incognita and M. javanica. At 60 days after inoculation, plant growth and nematode variables were assessed using standard procedures. Roots of all five Amaranthus cultivars were heavily galled, with limited cultivar × nematode interactions on plant variables. Additionally, the common factor that influenced either plant or nutrient element variables was the cultivar type, whereas those of nematodes were highly variable, particularly on nutrient elements. Three best performing cultivars were further tested under field conditions under nematode infested and untreated control plots. An exotic cv. ′Tanzania′ had higher dry shoot mass, plant height and stem diameter, and accumulated higher Ca and K content than ′Candatus′ and ′Local 33′. Overall, the cultivar × nematode interaction reduced Na content in leaf tissues of Amaranthus cultivars under field conditions. / University of Venda, University of Limpopo and Agricultural Research Council
12

UNDERSTANDING THE ROLE OF SECONDARY METABOLITES IN HEMP-WEED INTERACTIONS

shikanai, avery 01 December 2021 (has links)
Renewed interest in hemp (Cannabis sativa L.) for cannabinoid production has highlighted critical knowledge gaps for growers. The impacts of weed interference on hemp yield are largely unstudied despite causing serious economic losses in most cropping systems. Furthermore, understanding factors determining cannabinoid content of hemp will be crucial for effective production. To evaluate the effects of weed competition on hemp yield and cannabinoid content, hemp growing in plasticulture was subjected to competition from 5, 3, 1, or 0 waterhemp (Amaranthus tuberculatus (Moq.) Sauer) plants. Hemp biomass and cannabinoid content were not significantly affected by weed competition. Yields in weedy and weed-free treatments were generally comparable, although unexpectedly high variation limited the ability to detect subtle differences between treatments. Waterhemp biomass was significantly reduced by competition from hemp in comparison to hemp-free controls. Suppression of weed growth by hemp and lack of significant yield loss from weeds suggests that hemp can be highly competitive and grown successfully without herbicides in certain circumstances. Abundance and documented phytotoxicity of hemp secondary metabolites suggest a potential for allelopathic activity. While incorporated hemp residue was not more effective than a maize control at reducing plant growth, hemp residue and extracts effectively inhibit seed germination. A laboratory assay showed that crude extracts of hemp can reduce the germination of a Brassica napus L., a bioindicator. Furthermore, a greenhouse experiment showed that small amounts of hemp residue on the soil surface can effectively reduce and delay the germination of waterhemp. Together, these results show that hemp residue has the potential to be incorporated with a practice such as chaff-lining for enhanced control of germinating weed seeds.
13

Adaptations of five pale-type grain amaranth accessions (Amaranthus caudatus) and five ataco or sangorache accessions (Amaranthus hybridus) in the cities of Otavalo and Antonio Ante

Tuston Torres, Sixto Stalin 01 January 2007 (has links) (PDF)
This study was conducted in two locations: Pucará (2,413m above sea level) and Mojandita (2,922m above sea level), both of which are found in the province of Imbabura, Ecuador. The objectives of this study were to: characterize the morphological and agronomic traits as well as the overall quality of the ten amaranth accessions in this study; identify the accessions with the highest yield and biomass; determine the nutritional characteristics of the experimental accessions; and determine the cost of production of amaranth per hectare. The following null hypothesis was assumed: the agronomic and nutritional characteristics of the ten accessions in this study are equal in both locations. A randomized block design with ten treatments and three repetitions was employed for each location. The following tests of significance were performed: Tukey test at the 5% significance level for accessions, DMS at 5% for locations and Combined Analysis for the variety x location interaction. The following lines were used: ECU-0014, ECU-0113, ECU-2210, ECU-4737, ECU-4744, which represented pale-seeded grain types, and ECU-0069, ECU-0082, ECU-0102, ECU-0123 and ECU-0162 represented dark-seeded grain types. These accessions were analyzed for: plant height, diameter of the base of the stem, stem length, panicle length, grain/plot yield. Based on the results of this study, we conclude that no significant difference exists between the accessions on the basis of plant height and stem length in either location. For stem diameter, panicle length, and yield, however, significant differences among the accessions were detected. Between locations, the most promising results were observed in Pucará. The accession ECU-2210 gave the highest yield in Mojanda, with 1,300 kg/ha, while the accession ECU-0014 had the highest yield in Pucará, with 1,400 kg/ha. Overall, the best protein and iron content was observed in Mojanda; the accessions ECU-0162 and ECU-4744 had the highest percentage of protein, with 14.93% and 14.58% respectively. The highest observed iron content was 465.0 ppm in the accession ECU-0102. The cost of producing one hectare of cultivated amaranth grain is $1,543.95. The sale of this investment totaled $2,520, giving a cost-benefit ration of $0.63. Growing the accessions ECU-0612 and ECU-4744 is recommended if high protein content is desired, while the accession ECU-0102 is recommended in order to obtain the highest iron content. To obtain the highest yield per square meter, the accessions ECU-2210 is recommended at altitudes of 2,900m above sea level, while ECU-0014 is recommended for altitudes less than 2,600m. Based on the results of this study, it is not recommended that amaranth be planted at altitudes higher than 3,000m.
14

Evaluation of Macrophoma sp. as a potential mycoherbicide for the control of Amaranthus retroflexus L. (redroot pigweed)

Chin, Alice January 1995 (has links)
No description available.
15

Control, Assessment and Glyphosate Resistance of Palmer Amaranth (Amaranthus palmeri S. Wats) in Virginia

Ahmed, Amro Mohamed Aly Tawfic 08 September 2011 (has links)
Glyphosate resistant crops were rapidly adopted by farmers since their introduction in 1996 and currently, greater than 90% of cotton and soybean crops are glyphosate resistant. Glyphosate has been an effective mean for controlling Palmer amaranth, however overreliance on glyphosate based systems resulted in weeds that can no longer be controlled with glyphosate. Palmer amaranth resistance to glyphosate has been confirmed in ten US states including Virginia's bordering neighbor North Carolina. The objectives of this study were to i) determine the spread of Palmer amaranth and evaluate awareness among farmers and agribusinesses of herbicide resistant weeds in Virginia; ii) determine the efficacy of commonly used cotton and soybean herbicides programs for Palmer amaranth control; and iii) conduct greenhouse experiments to quantify the level of glyphosate resistance in a Greensville County, Virginia population. Using a communication network of Virginia county extension agents and crop advisers, Palmer amaranth was found in 15 Virginia counties. A survey was conducted to evaluate awareness of herbicide resistance and management of weeds in Virginia. Ninety percent of producers had fields planted to Roundup Ready® crops for each of the last 3 years. One hundred percent of the responders claimed awareness of the potential for weeds to develop resistance to glyphosate, but when asked about how serious they consider weed resistance to herbicides, the responders average rating was of 7.9 (on a scale of 1 to 10 where 1 is "not at all serious" and 10 is "very serious" ). Eighteen percent of the responder population claimed no awareness of glyphosate resistant weeds documented in Virginia. Herbicide efficacy experiments were established in soybean and cotton fields infested with Palmer amaranth. In soybean, experiments were established in a field where Palmer amaranth was not adequately controlled with glyphosate in the previous year. Glyphosate applied at 0.87 + 0.87 + 1.74 kg ae ha⁻¹ at 1, 3, and 5 weeks after planting (WAP) provided 82 to 85% control in 2009, but only 23 to 30% control in 2010, a hot and dry year. Glyphosate applied after preemergence (PRE) herbicides improved control to 90 percent. Programs that included s-metolachlor + metribuzin applied preemergence and followed by glyphosate + fomesafen applied postemergence provided the best control (93%) at 8 WAP. Glufosinate based herbicide programs provided greater than 85% control when applied alone, and control increased to 95% when preceded by PRE herbicides. Many conventional control systems integrating different modes of action provided more than 80% control at final evaluation of Palmer amaranth in 2009 and 2010. In soybean, the most consistent and effective program was flumioxazin applied PRE followed by chlorimuron + thifensulfuron, which provided 99 and 82% control at final evaluation in 2009 and 2010, respectively. Cotton fields were heavily infested with Palmer amaranth, but control with glyphosate had historically been good. Glyphosate applied early postemergence, late postemergence, and late post-directed provided more than 95 percent control at final evaluation of Palmer amaranth. Preemergence applications of fomesafen, fluometuron, or pendimethalin + fomesafen provided 77 to 99 percent early-season control and control was complete with an additional postemergence glyphosate application. Glufosinate applied at 0.45 kg ha⁻¹ at 1 and 3 WAP or applied at 0.45 kg ha⁻¹ following a preemergence herbicide provided greater than 95% control. Greenhouse experiments confirmed Palmer amaranth resistance in a population collected from Greensville County, Virginia. In the first experiment, the resistant biotype's I₅₀ value (rate necessary for 50% inhibition) for dry weight was 1.47 kg ae ha⁻¹, which is 4.6 times greater than the susceptible biotype and 1.7 times the recommended use rate of glyphosate. For fresh weight, the I₅₀ value of the resistant biotype was 1.60 kg ae ha⁻¹, 4.7 times that of the susceptible biotype of 0.34 kg ae ha⁻¹. In the second experiment, the I₅₀ value for the susceptible population could not be determined because all glyphosate rates resulted in complete control. However, the resistant population required 1.01 and 1.30 kg ae ha⁻¹ of glyphosate to reduce the fresh and dry weight by 50%. / Master of Science
16

Substituição parcial de farinha de trigo por farinha de amaranto (Amaranthus cruentus L.), quinoa (Chenopodium quinoa W.) e maca (Lepidium meyenii W.) na elaboração de panetone / Partial substitution of wheat flour by amaranth (Amaranthus cruentus L.), quinoa (Chenopodium quinoa W.) and maca (Lepidium meyenii W.) flours in the preparation of panettone

Valcarcel Yamani, Beatriz 02 June 2015 (has links)
O aumento da demanda por alimentos saudáveis está estimulando inovações e o desenvolvimento de novos produtos na indústria de alimentos. O amaranto (Amaranthus cruenthus L.) e a quinoa (Chenopodium quinoa W.) são pseudocereais que apresentam proteínas de elevado valor biológico e ácidos graxos insaturados além de outros compostos que atuam como antioxidantes. A maca (Lepidium meyenii W.), uma raiz anual ou bienal, é usada como ingrediente alimentar devido ao seu valor nutricional e conteúdo de fitoquímicos. Neste trabalho, objetivou-se avaliar o efeito da adição das farinhas destas cullturas em diferentes níveis sobre as propriedades físico-químicas, reológicas e sensoriais de panetone. Farinhas mistas de trigo e amaranto, quinoa ou maca nas porcentagens de 10 %, 20 %, 30 % e 40 % de adição, foram avaliadas durante as diferentes etapas de produção: misturas de farinhas, massa fermentada, massa assada e produto acabado. A adição favoreceu o escurecimento gradual das farinhas e variação no tamanho médio das partículas. Nas massas, foi observada a diminuição gradativa dos valores de estabilidade ao amassamento e tempo de desenvolvimento com diminuição da extensibilidade e aumento da resistência das massas. Nas massas fermentadas, a adição de 10 e 20 % de farinha de amaranto ou quinoa e 30 % de farinha de amaranto, não incrementou significativamente (p > 0,05) a firmeza da massa. No entanto, as formulações contendo farinha de maca mostraram aumento significativo (p < 0,05) no ponto de quebra, firmeza, consistência, coesividade e viscosidade da massa. O aumento da resistência com diminuição gradativa da extensibilidade das massas também foi observado. Nas massas assadas, houve diminuição da área total de células com aumento no número de células de gás de menor tamanho em amostras com adição de farinha de maca e amaranto. As formulações com 10 % de farinha de maca, 10 e 20 % de farinha de amaranto ou quinoa e 30 % de farinha de amaranto, apresentaram os melhores resultados, com valores de volume, altura, cor e firmeza próximos à formulação controle. A análise sensorial mostrou que o produto elaborado com adição de 30 % de farinha de amaranto apresentou a melhor aceitabilidade e intenção de compra. Dentro das condições experimentais, o panetone contendo 30 % de farinha de amaranto foi o mais promissor pela boa aceitabilidade do consumidor, podendo contribuir para incrementar a qualidade do produto. O panetone com 10 % de adição de farinha de maca também apresentou valores interessantes com pouca diferença se comparado com aquele enriquecido com farinha de amaranto. Na amostra contendo farinha de quinoa, a substituição com menos de 20 % de adição melhoraria a aceitabilidade do panetone enriquecido. / The increased demand for healthy foods is stimulating innovation and new product development in the food industry. Amaranth (Amaranthus cruenthus L.) and quinoa (Chenopodium quinoa W.) are pseudocereals which have proteins with high biological value and unsaturated fatty acids, as well as other compounds which act as antioxidants. Maca (Lepidium meyenii W.), an annual or biennial root, is used as a food ingredient for human consumption due to its nutritional value and phytochemical content. The objective of this study was to evaluate the effect of amaranth, quinoa and maca flour addition at different levels on the physical-chemical, rheological and sensory properties of panettone. Composite flours of wheat and amaranth, quinoa or maca flours in percentages of 10 %, 20 %, 30 % and 40 % addition were evaluated during the different stages of production: flour blends, fermented dough, baked dough and finished product. The addition promoted a gradual flour darkening and tendency to yellow and red colors. In the dough, the gradual decrease in stability values to kneading and development time with decreased extensibility and increased dough resistance, were observed. In fermented doughs, the addition of 10 % - 20 % amaranth or quinoa flour and 30 % amaranth flour, did not increased significantly (p > 0.05) the dough firmness. However, formulations containing maca flour showed a significant increase (p < 0.05) of break point, firmness, consistency, cohesiveness and viscosity of the dough. Furthermore, it was also observed an increase in dough resistance with a gradual decrease in extensibility. In baked samples, there was a decrease of the total cell area with increased number of smaller gas cells in samples with maca and amaranth flour addition. Better results were observed in formulations with 10% maca flour, 10 - 20 % amaranth or quinoa flour and 30 % amaranth flour with values of volume, height, color and firmness close to the control. Sensorial analysis showed that sample containing 30 % addition of amaranth flour showed the better acceptability and purchase intention by consumers. Within these experimental conditions, panettone containing 30 % amaranth flour was the most promising for the good acceptability of the consumer and may contribute to improve the quality of the product. Sample with 10 % maca flour addition also showed interesting values with few differences when compared to that enriched with amaranth flour. In sample containing quinoa flour, wheat flour substitution with less than 20 % would improve the acceptability of the enriched panettone.
17

Substituição parcial de farinha de trigo por farinha de amaranto (Amaranthus cruentus L.), quinoa (Chenopodium quinoa W.) e maca (Lepidium meyenii W.) na elaboração de panetone / Partial substitution of wheat flour by amaranth (Amaranthus cruentus L.), quinoa (Chenopodium quinoa W.) and maca (Lepidium meyenii W.) flours in the preparation of panettone

Beatriz Valcarcel Yamani 02 June 2015 (has links)
O aumento da demanda por alimentos saudáveis está estimulando inovações e o desenvolvimento de novos produtos na indústria de alimentos. O amaranto (Amaranthus cruenthus L.) e a quinoa (Chenopodium quinoa W.) são pseudocereais que apresentam proteínas de elevado valor biológico e ácidos graxos insaturados além de outros compostos que atuam como antioxidantes. A maca (Lepidium meyenii W.), uma raiz anual ou bienal, é usada como ingrediente alimentar devido ao seu valor nutricional e conteúdo de fitoquímicos. Neste trabalho, objetivou-se avaliar o efeito da adição das farinhas destas cullturas em diferentes níveis sobre as propriedades físico-químicas, reológicas e sensoriais de panetone. Farinhas mistas de trigo e amaranto, quinoa ou maca nas porcentagens de 10 %, 20 %, 30 % e 40 % de adição, foram avaliadas durante as diferentes etapas de produção: misturas de farinhas, massa fermentada, massa assada e produto acabado. A adição favoreceu o escurecimento gradual das farinhas e variação no tamanho médio das partículas. Nas massas, foi observada a diminuição gradativa dos valores de estabilidade ao amassamento e tempo de desenvolvimento com diminuição da extensibilidade e aumento da resistência das massas. Nas massas fermentadas, a adição de 10 e 20 % de farinha de amaranto ou quinoa e 30 % de farinha de amaranto, não incrementou significativamente (p > 0,05) a firmeza da massa. No entanto, as formulações contendo farinha de maca mostraram aumento significativo (p < 0,05) no ponto de quebra, firmeza, consistência, coesividade e viscosidade da massa. O aumento da resistência com diminuição gradativa da extensibilidade das massas também foi observado. Nas massas assadas, houve diminuição da área total de células com aumento no número de células de gás de menor tamanho em amostras com adição de farinha de maca e amaranto. As formulações com 10 % de farinha de maca, 10 e 20 % de farinha de amaranto ou quinoa e 30 % de farinha de amaranto, apresentaram os melhores resultados, com valores de volume, altura, cor e firmeza próximos à formulação controle. A análise sensorial mostrou que o produto elaborado com adição de 30 % de farinha de amaranto apresentou a melhor aceitabilidade e intenção de compra. Dentro das condições experimentais, o panetone contendo 30 % de farinha de amaranto foi o mais promissor pela boa aceitabilidade do consumidor, podendo contribuir para incrementar a qualidade do produto. O panetone com 10 % de adição de farinha de maca também apresentou valores interessantes com pouca diferença se comparado com aquele enriquecido com farinha de amaranto. Na amostra contendo farinha de quinoa, a substituição com menos de 20 % de adição melhoraria a aceitabilidade do panetone enriquecido. / The increased demand for healthy foods is stimulating innovation and new product development in the food industry. Amaranth (Amaranthus cruenthus L.) and quinoa (Chenopodium quinoa W.) are pseudocereals which have proteins with high biological value and unsaturated fatty acids, as well as other compounds which act as antioxidants. Maca (Lepidium meyenii W.), an annual or biennial root, is used as a food ingredient for human consumption due to its nutritional value and phytochemical content. The objective of this study was to evaluate the effect of amaranth, quinoa and maca flour addition at different levels on the physical-chemical, rheological and sensory properties of panettone. Composite flours of wheat and amaranth, quinoa or maca flours in percentages of 10 %, 20 %, 30 % and 40 % addition were evaluated during the different stages of production: flour blends, fermented dough, baked dough and finished product. The addition promoted a gradual flour darkening and tendency to yellow and red colors. In the dough, the gradual decrease in stability values to kneading and development time with decreased extensibility and increased dough resistance, were observed. In fermented doughs, the addition of 10 % - 20 % amaranth or quinoa flour and 30 % amaranth flour, did not increased significantly (p > 0.05) the dough firmness. However, formulations containing maca flour showed a significant increase (p < 0.05) of break point, firmness, consistency, cohesiveness and viscosity of the dough. Furthermore, it was also observed an increase in dough resistance with a gradual decrease in extensibility. In baked samples, there was a decrease of the total cell area with increased number of smaller gas cells in samples with maca and amaranth flour addition. Better results were observed in formulations with 10% maca flour, 10 - 20 % amaranth or quinoa flour and 30 % amaranth flour with values of volume, height, color and firmness close to the control. Sensorial analysis showed that sample containing 30 % addition of amaranth flour showed the better acceptability and purchase intention by consumers. Within these experimental conditions, panettone containing 30 % amaranth flour was the most promising for the good acceptability of the consumer and may contribute to improve the quality of the product. Sample with 10 % maca flour addition also showed interesting values with few differences when compared to that enriched with amaranth flour. In sample containing quinoa flour, wheat flour substitution with less than 20 % would improve the acceptability of the enriched panettone.
18

Otimização de propriedades nutricionais e sensoriais de produtos à base de amaranto enriquecidos com frutanos, para intervenção em celíacos / Nutritional and sensory optimization of amaranth based products enriched with fructans, for nutritional intervention in celiac

Capriles, Vanessa Dias 17 December 2009 (has links)
Introdução: A doença celíaca não tem cura e apresenta como único tratamento a dieta isenta de glúten. Frequentemente observa-se a má absorção de cálcio em celíacos, consequência dos menores níveis de transportadores de cálcio no enterócito desses indivíduos. Os celíacos têm dificuldade em dar sequência ao tratamento dietético devido à escassez de produtos isentos de glúten, tornando fundamental o desenvolvimento de produtos para esta população. Isso pode ser feito por meio do uso de matérias primas isentas de glúten e com valor nutritivo agregado, como o grão de amaranto, e de ingredientes que contribuem para o aumento da absorção de cálcio através de absorção passiva nos colonócitos, como os frutanos inulina e oligofrutose. Objetivo: Desenvolver e otimizar as propriedades nutricionais e sensoriais de produtos à base de amaranto enriquecidos com frutanos, para intervenção nutricional em celíacos. Metodologia: Foram elaborados snacks à base de milho e amaranto (50, 75 e 100%), barras e pães sem glúten, enriquecidos com 4 gramas de frutanos/ porção. Para maximizar a aceitabilidade das barras foi utilizado um planejamento experimental para misturas de amaranto extrusado, estourado e laminado. Para maximizar o valor nutritrivo e a aceitabilidade do pão sem glúten foi utilizado o planejamento experimental para misturas de farinha de arroz, fécula de batata e farinha de amaranto. Os produtos foram caracterizados quanto a composição centesimal, o índice glicêmico (IG) e a carga glicêmica (CG). Também foram avaliadas as propriedades físicas e a aceitabilidade (escala hedônica estruturada de nove pontos) durante o período de armazenamento. Resultados e discussão: Os snacks foram aceitos e apresentaram estabilidade de suas características físicas e da aceitabilidade durante os 135 dias de armazenamento. O efeito combinado do amaranto e dos frutanos gerou redução de 19% do IG e de 56% da CG dos snacks. O amaranto estourado e laminado apresentaram interações sinérgicas para a aceitabilidade das barras (R2(aj)>92%, p=0,00). A formulação à base de amaranto estourado e laminado (½,½) foi diversificada em seis diferentes sabores e apresentou estabilidade de suas propriedades físicas e da aceitabilidade durante os seis meses de armazenamento. A estimativa da resposta glicêmica revelou IG moderado e CG baixa das barras. Pães com 33 e 45% de farinha de amaranto apresentaram destacado valor nutritivo e aceitabilidade. A incorporação de amaranto e de frutanos ocasionou redução de 20% do IG e de até 53% da CG do pão sem glúten. Conclusão: Os produtos desenvolvidos (snacks, barras e pães sem glúten) apresentaram destacado valor nutritivo em relação aos produtos convencionais, atenuação da resposta glicêmica e alta aceitabilidade pelo consumidor, podendo contribuir para uma maior variação e adequação da dieta dos celíacos e também para auxiliar no aumento da absorção de cálcio / Introduction: Celiac disease does not have a cure and the only scientifically proven treatment is strict lifelong adherence to a gluten-free diet. Calcium malabsorption is frequently found in celiac, possibly due to negligible amounts of calcium-binding protein in their enterocytes. Compliance with dietary treatment is often difficult due to the lack of gluten-free products, so it is essential to develop specific products for this population. This can be done through the use of gluten-free raw materials of great nutritional value, such as amaranth grain, and ingredients that contribute to the calcium absorption increasement through passive absorption in colonocytes, such as the fructans inulin and oligofructose. Objective: Develop and optimize the nutritional and sensory properties of amaranth based products enriched with fructans, for nutritional intervention in celiac. Methods: Snacks from blends of corn and amaranth (50, 75 and 100%), amaranth bars and gluten-free bread, all enriched with 4 grams of fructans/ portion, were prepared. A mixture experiment of extruded, popped and flaked amaranth was used to optimize the sensory acceptability of the bars. A mixture experiment of rice flour, potato starch and amaranth flour was used to maximize the nutritional value and sensory acceptability of gluten-free bread. Products chemical composition, glycemic index (GI) and glycemic load (GL), were evaluated. The physical properties and sensory acceptability (nine point hedonic scale) were assessed during the storage time. Results and discussion: Snacks were sensory accepted and maintained their physical characteristics and sensory acceptability during the 135 days of storage. The combined effect of amaranth and fructans resulted in 19% reduction of GI and 56% of GL of snacks. Popped and flaked amaranth present synergistic interactions to sensory acceptability of the bars (R2(adj)>92%, p=0,00). Bars were produced with popped and flaked amaranth (½,½) in six different flavors and its physical properties and sensory acceptability were stable during the six months of storage. The predicted glycemic response showed moderate GI and low GL bars. Breads with 33 and 45% of amaranth flour had higher nutritional value and sensory acceptability. Amaranth and fructans addition led to a reduction of approximately 20% of GI and up to 53% of the GL of gluten-free breads. Conclusion: The developed products (snacks, bars and gluten-free breads) had superior nutritional composition than conventional products, reduced glycemic response, high consumer sensory acceptability, great potential to contribute to variation and adequacy of celiac diet and also help to increase calcium absorption.
19

Ecology of Bird Island, North Carolina an uninhabited, undeveloped barrier island /

Rosenfeld, Kristen Marie. Wentworth, Thomas R. Suiter, Dale William. January 2004 (has links)
Thesis (M.S.)--North Carolina State University, 2004. / Title from PDF title page (viewed on Apr. 3, 2005). Includes vita. Includes bibliographical references.
20

Otimização de propriedades nutricionais e sensoriais de produtos à base de amaranto enriquecidos com frutanos, para intervenção em celíacos / Nutritional and sensory optimization of amaranth based products enriched with fructans, for nutritional intervention in celiac

Vanessa Dias Capriles 17 December 2009 (has links)
Introdução: A doença celíaca não tem cura e apresenta como único tratamento a dieta isenta de glúten. Frequentemente observa-se a má absorção de cálcio em celíacos, consequência dos menores níveis de transportadores de cálcio no enterócito desses indivíduos. Os celíacos têm dificuldade em dar sequência ao tratamento dietético devido à escassez de produtos isentos de glúten, tornando fundamental o desenvolvimento de produtos para esta população. Isso pode ser feito por meio do uso de matérias primas isentas de glúten e com valor nutritivo agregado, como o grão de amaranto, e de ingredientes que contribuem para o aumento da absorção de cálcio através de absorção passiva nos colonócitos, como os frutanos inulina e oligofrutose. Objetivo: Desenvolver e otimizar as propriedades nutricionais e sensoriais de produtos à base de amaranto enriquecidos com frutanos, para intervenção nutricional em celíacos. Metodologia: Foram elaborados snacks à base de milho e amaranto (50, 75 e 100%), barras e pães sem glúten, enriquecidos com 4 gramas de frutanos/ porção. Para maximizar a aceitabilidade das barras foi utilizado um planejamento experimental para misturas de amaranto extrusado, estourado e laminado. Para maximizar o valor nutritrivo e a aceitabilidade do pão sem glúten foi utilizado o planejamento experimental para misturas de farinha de arroz, fécula de batata e farinha de amaranto. Os produtos foram caracterizados quanto a composição centesimal, o índice glicêmico (IG) e a carga glicêmica (CG). Também foram avaliadas as propriedades físicas e a aceitabilidade (escala hedônica estruturada de nove pontos) durante o período de armazenamento. Resultados e discussão: Os snacks foram aceitos e apresentaram estabilidade de suas características físicas e da aceitabilidade durante os 135 dias de armazenamento. O efeito combinado do amaranto e dos frutanos gerou redução de 19% do IG e de 56% da CG dos snacks. O amaranto estourado e laminado apresentaram interações sinérgicas para a aceitabilidade das barras (R2(aj)>92%, p=0,00). A formulação à base de amaranto estourado e laminado (½,½) foi diversificada em seis diferentes sabores e apresentou estabilidade de suas propriedades físicas e da aceitabilidade durante os seis meses de armazenamento. A estimativa da resposta glicêmica revelou IG moderado e CG baixa das barras. Pães com 33 e 45% de farinha de amaranto apresentaram destacado valor nutritivo e aceitabilidade. A incorporação de amaranto e de frutanos ocasionou redução de 20% do IG e de até 53% da CG do pão sem glúten. Conclusão: Os produtos desenvolvidos (snacks, barras e pães sem glúten) apresentaram destacado valor nutritivo em relação aos produtos convencionais, atenuação da resposta glicêmica e alta aceitabilidade pelo consumidor, podendo contribuir para uma maior variação e adequação da dieta dos celíacos e também para auxiliar no aumento da absorção de cálcio / Introduction: Celiac disease does not have a cure and the only scientifically proven treatment is strict lifelong adherence to a gluten-free diet. Calcium malabsorption is frequently found in celiac, possibly due to negligible amounts of calcium-binding protein in their enterocytes. Compliance with dietary treatment is often difficult due to the lack of gluten-free products, so it is essential to develop specific products for this population. This can be done through the use of gluten-free raw materials of great nutritional value, such as amaranth grain, and ingredients that contribute to the calcium absorption increasement through passive absorption in colonocytes, such as the fructans inulin and oligofructose. Objective: Develop and optimize the nutritional and sensory properties of amaranth based products enriched with fructans, for nutritional intervention in celiac. Methods: Snacks from blends of corn and amaranth (50, 75 and 100%), amaranth bars and gluten-free bread, all enriched with 4 grams of fructans/ portion, were prepared. A mixture experiment of extruded, popped and flaked amaranth was used to optimize the sensory acceptability of the bars. A mixture experiment of rice flour, potato starch and amaranth flour was used to maximize the nutritional value and sensory acceptability of gluten-free bread. Products chemical composition, glycemic index (GI) and glycemic load (GL), were evaluated. The physical properties and sensory acceptability (nine point hedonic scale) were assessed during the storage time. Results and discussion: Snacks were sensory accepted and maintained their physical characteristics and sensory acceptability during the 135 days of storage. The combined effect of amaranth and fructans resulted in 19% reduction of GI and 56% of GL of snacks. Popped and flaked amaranth present synergistic interactions to sensory acceptability of the bars (R2(adj)>92%, p=0,00). Bars were produced with popped and flaked amaranth (½,½) in six different flavors and its physical properties and sensory acceptability were stable during the six months of storage. The predicted glycemic response showed moderate GI and low GL bars. Breads with 33 and 45% of amaranth flour had higher nutritional value and sensory acceptability. Amaranth and fructans addition led to a reduction of approximately 20% of GI and up to 53% of the GL of gluten-free breads. Conclusion: The developed products (snacks, bars and gluten-free breads) had superior nutritional composition than conventional products, reduced glycemic response, high consumer sensory acceptability, great potential to contribute to variation and adequacy of celiac diet and also help to increase calcium absorption.

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