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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.
51

An assessment of the quality and acceptance of a ready-to-use supplement, Sibusiso, by human immunodeficiency virus and human immunodeficiency virus/tuberculosis treated patients in KwaZulu-Natal.

Mabaso, Prudence Bongekile. 29 November 2013 (has links)
Introduction: Malnutrition is a health issue directly and indirectly contributing towards high rates of morbidity and mortality globally, particularly in developing countries. South Africa (SA) is faced with a double burden of diseases with a high prevalence of both under and over nutrition. The high prevalence of Human Immunodeficiency Virus/Acquired Immune Deficiency Syndrome (HIV/AIDS) in SA worsens undernutrition. HIV/AIDS increases nutrient requirements and inadequate food intake results in malnutrition. Nutrition support through food supplementation is important to combat the high prevalence of malnutrition in sub-Saharan African countries including South Africa. Thus, a groundnut-soya based supplementary paste, Sibusiso, has been produced. However, its nutritional composition and acceptability have not been studied. Objectives: (i) To determine the nutritional composition and physical properties of a ready-to-use supplement, Sibusiso, (ii) To determine the sensory acceptability of Sibusiso among healthy subjects; and sensory acceptability and perceptions of Sibusiso by subjects treated for HIV and HIV/TB. Materials and methods: The nutritional composition, colour and texture of Sibusiso and a commercial peanut butter (control) were analysed following standard procedures. A cross-sectional consumer acceptability test was done using a 5-point facial hedonic scale (healthy control group, n = 68; HIV, n = 88 and HIV-TB co-infection treated, n = 51). A total of six focus group discussion sessions (HIV subjects = 4 sessions and HIV/TB co-infected subjects = 2 sessions) were also conducted. Results and discussions: The protein content of Sibusiso (16 g/100 g) was almost half that of the commercial peanut butter (control), (25 g/100 g). However, Sibusiso contained 1.4 times more ash (4 g/100 g) and almost twice as much carbohydrate (40 g/100 g) compared to the commercial peanut butter (22 g/100 g). The fat (40 g/100 g) and energy (2 624 kJ/ 100 g) content of Sibusiso was not substantially different from that of the commercial peanut butter which was 43 g/100 g and 2 852 kJ/100 g, respectively. The lysine content of Sibusiso (58 mg/g) was about 1.7 times higher than that of the commercial peanut butter. The methionine (11 mg/g) and histidine (35 mg/g) content of Sibusiso was almost twice that of the commercial peanut butter, respectively. The nutrient content of Sibusiso was either similar or slightly more than that of other ready-to-use supplements such as Plumpy’nut®. Sibusiso met the FAO/WHO/UNU recommendations for essential amino acids. The consumption of 50 g of Sibusiso per day may provide approximately 35% of the Estimated Energy Requirements (EER) and 30% of the Recommended Dietary Allowance (RDA) for protein for adults. Sibusiso was brown in colour, similar to the commercial peanut butter. Its textural attributes were found similar to that of the commercial peanut butter but harder and stickier. The acceptability of Sibusiso was significantly associated (p ≤ 0.05) with the health status of consumers. Overall, Sibusiso was liked by 94% of HIV and HIV/TB individuals (mean score: 4) compared to 85% for the healthy group (control). More than 90% of the HIV/TB and HIV treated individuals liked the taste compared to the control group (86%, mean score: 4). The colour and mouthful were rated 'good' by more than 80% of the HIV and HIV/TB group, mean score: 3, with only 68% among the healthy group, mean score: 4.1. Conclusion: Sibusiso is a good source of nutrients and was found to be acceptable to HIV and HIV/TB treated consumers. It may be effective in alleviating disease-related malnutrition among vulnerable individuals such as those infected by HIV and HIV/TB. / Thesis (M.Sc.Hum.Nut.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
52

A study of the quality and feasibility of Sibusiso, a ready-to-use food.

Mahlangu, Zodwa Nita. January 2012 (has links)
A ready-to-use food (RUF), Sibusiso, has the potential to alleviate protein- energy malnutrition. However, its nutritional composition, physical properties, consumer acceptability, and economic feasibility for use are unknown. This study aimed to determine the nutritional composition and physical properties of a RUF, Sibusiso. As well as to assess the consumer acceptability of Sibusiso to healthy and HIV infected children on antiretroviral (ARV) medication, and the caregiver‟s attitudes towards Sibusiso. The feasibility of using Sibusiso for nutrition rehabilitation was also determined. Methodology: Four samples of Sibusiso and a peanut butter (control) were analysed for their nutritional composition and physical properties. The consumer acceptability of Sibusiso to healthy children and HIV infected children on ARVs (ART group) was determined using a five-point facial hedonic rating scale. Focus group discussions were conducted to assess the attitudes and perceptions of caregivers surrounding Sibusiso. These caregivers had children who were either malnourished or at risk of malnutrition. The financial feasibility of using Sibusiso for nutrition rehabilitation was determined using published data. The results revealed that Sibusiso was a good source of energy (2624 kJ/100 g) and quality protein (15.7 g/100 g). The nutritional composition of Sibusiso met the WHO/WFP/SCN/UNICEF recommendations for RUF. Instrumental colour analysis indicated that both Sibusiso and the peanut butter had a brown colour, although Sibusiso was slightly lighter. Sibusiso had the same spreadability or hardness as the peanut butter, but it was stickier than the peanut butter. Based on the sensory evaluation, Sibusiso was found acceptable to both healthy (n=121) and HIV infected children (n=51). Over 65% of the children in both the healthy and ART group liked the taste, smell and mouthfeel of Sibusiso. The caregivers also found Sibusiso acceptable and were willing to buy it, but at half its current price (60 ZAR/ 500 g). The price of Sibusiso and perception of the caregivers that Sibusiso was a peanut butter were the main factors that affected their willingness to buy the product. Financial feasibility analysis showed that the estimated cost (5.99 ZAR/day) of rehabilitating a child using Sibusiso was higher than the KwaZulu-Natal Department of Health nutrition budget of 0.02 ZAR/day. Sibusiso is a good source of energy and quality protein, and it is fairly acceptable to children with HIV and caregivers. This indicates that Sibusiso has a potential to alleviate protein-energy malnutrition in the targeted groups. Yet, Sibusiso is expensive. There would be a need to somehow reduce the cost of Sibusiso so that it would be financially feasible to use it in nutrition intervention programmes. / Thesis (M.Sc.Hum.Nut.)-University of KwaZulu-Natal, Pietermaritzburg, 2012.
53

Estimativa da vida útil de hambúrguer de Carpa capim por meio de análise de sobrevivência, cut-off point e espectroscopia de infravermelho próximo / Shelf life estimation of grass carp hamburger through survival analysis, cut-off point and near-infrared spectroscopy

Marques, Caroline 07 December 2016 (has links)
CAPES; CNPq / O consumo de pescado no Brasil está abaixo da média mundial e isso se deve a fatores econômicos, culturais e também à baixa disponibilidade desse alimento. Para estimular o consumo, devido ao alto valor nutricional desse tipo de carne, uma das estratégias é transformar o pescado em um produto prático, como o hambúrguer. Entretanto, em decorrência do pH próximo a neutralidade e da alta atividade de água, o pescado e seus derivados possuem uma vida útil limitada, dependendo das condições de armazenamento. Um dos parâmetros mais questionáveis da estabilidade desse produto é a oxidação lipídica, reação que ocorre até mesmo em baixas temperaturas. Sabe-se que a qualidade sensorial de um produto é fundamental para o consumidor na hora da compra e do consumo. Uma vez que o acompanhamento sensorial da vida útil leva tempo e considerável investimento, a Espectroscopia de Infravermelho Próximo (NIR) entra como técnica instrumental rápida, não destrutiva e recente, para o mesmo fim, a qual consegue analisar vários parâmetros da amostra ao mesmo tempo. Nesse sentido, o objetivo deste trabalho foi estimar a vida útil de hambúrgueres de Carpa capim por meio de análise de sobrevivência e cut-off point, além da utilização do NIR para construção de modelos de predição de vida útil pelo método dos mínimos quadrados parciais (PLS).O hambúrguer foi elaborado com filés de Carpa capim moídos e lavados (lavagem básica), embalados a vácuo e armazenados sob refrigeração durante 30 dias. Uma equipe sensorial foi selecionada e treinada para avaliar o ranço nas amostras de hambúrguer por meio de análise discriminativa triangular, análise estatística de variância (ANOVA), gráfico de valor F e box plots. A avaliação físico-química da matéria-prima mostrou adequação com a legislação vigente para frescor (pH e bases voláteis totais N-BVT); apresentou baixo teor de lipídios e alto conteúdo proteico. A caracterização do produto verificou que o hambúrguer de Carpa capim está de acordo com a legislação quanto ao teor de lipídios e proteína, com valor semelhante ao dos filés para o valor calórico. As análises de referência para o NIR apontaram que o Índice de iodo e a atividade de água (Aw) não foram capazes de diferenciar os hambúrgueres durante o armazenamento; já as Substâncias Reativas do Ácido Tiobarbitúrico (TBARS) e o pH apresentaram resultados que corroboram as mudanças ocorridas na matriz hambúrguer. A rancidez foi observada pela equipe sensorial treinada e também verificada pela análise de TBARS, as quais tiveram crescimento exponencial, com coeficientes de correlação superiores a 0,95. Modelos robustos por meio do PLS foram obtidos com o NIR para os parâmetros ranço, TBARS e pH, resultado que não se repetiu para o Índice de iodo, Aw e cor. A análise de sobrevivência determinou o final da vida útil do hambúrguer de Carpa Capim em 17 dias, já para o cut-off point apontou 15 dias. Ambas as metodologias mostraram-se eficientes para estimativa da vida útil do produto analisado, ao contrário do NIR que subestimou a data da vida útil, gerando diferenças de 56 a 76% e não se mostrou eficiente para a estimativa considerando os valores preditos pelo modelo gerado para o defeito ranço. / The fish consumption in Brazil is below the world average and this is due to economic, cultural factors and also to the low availability of this food. To stimulate consumption, due to the high nutritional value of this type of meat, one of the strategies is to turn the fish into a convenient product, such as hamburger. However, due to the pH close to neutrality and the high water activity, fish and fish products have a limited shelf life, depending on storage conditions. One of the questionable parameters about the stability of this product is the lipid oxidation reaction, which occurs even at low temperatures. It is known that the sensory quality of a product is critical to the consumer at the moment of acquisition and consumption. Once the sensory monitoring of the shelf life takes time and considerable investment, the Near Infrared spectroscopy (NIR) comes as a fast instrumental technique, nondestructive and recent, with the same purpose, which can access multiple parameters from the sample at the same time. Thus, the objective of this study was to estimate the shelf life of grass carp burgers through survival analysis and cut-off point, in addition to the use of NIR to build shelf life prediction models by the Partial Least Squares (PLS) method. The burger was made with grass carp fillets ground and washed (basic washing), vacuum packed and stored under refrigeration for 30 days. A sensory panel was selected and trained to evaluate rancidity in hamburger samples by means of triangular discriminative analysis, variance statistical analysis (ANOVA), F value chart and box plots. The physical-chemical evaluation of raw materials showed adequacy with current legislation for freshness (pH and total volatile bases TVB-N); presented low lipid content and high protein content. The characterization of the product verified that the burger complies with the legislation on the lipid and protein content, with a caloric value similar to the fillets. The reference analyzes for NIR pointed out that the iodine index and water activity (Aw) were not able to differentiate the burgers during storage; the Thiobarbituric Acid Reactive Substances (TBARS) and the pH presented results corroborating the changes in the burger matrix. The rancidity was observed by the trained sensory panel and also verified by TBARS analysis, where both had exponential growth, with correlation coefficients greater than 0.95. Robust models were obtained through PLS using the NIR to rancidity, TBARS and pH parameters, a result not repeated for iodine index, Aw and color. Survival analysis determined the end of shelf life of grass carp grass burger in 17 days and the cut-off point in 15 days. Both methods were effective to estimate the shelf life of the product, unlike the NIR that underestimated the end date, generating differences ranging from 56 to 76%, not efficient for this estimative, considering the values predicted by the model generated for the defect rancidity.
54

Farinhas comerciais de frutas: caracterização física, físico-química e análise de imagem digital / Commercial fruit flour: physical, physicochemical characterization and digital image analysis

De Carli, Caroline Giane 13 February 2017 (has links)
A diversidade de frutas produzidas no Brasil constituiu-se numa alternativa de consumo quando industrializadas na forma de farinha tornando-se fonte de compostos bioativos, fibra alimentar e minerais. Podem ainda, ter seu uso inserido como ingrediente no desenvolvimento de novos produtos alimentícios mais saudáveis e isentos ou com reduzido teor de glúten. O presente trabalho objetivou a caracterização, estudo da composição química e qualidade nutricional de farinhas comerciais de frutas, bem como, o uso da tecnologia de imagem digital para estabelecer seus padrões de colorações. Coletaram-se 10 diferentes farinhas comerciais de frutas sendo elas, açaí (AÇ), ameixa (AM), banana verde (BV), coco (CO), laranja (LA), limão (LI), maçã (MA), mamão (MM), maracujá (MR) e uva (UV) e para cada tipo de farinha três lotes distintos foram avaliados. Realizaram-se as medidas em triplicata dos parâmetros de umidade, atividade de água, resíduo mineral fixo, proteínas, fibra alimentar (duplicata), pH, minerais como Cu (cobre), Fe (ferro), Zn (zinco), Mn (manganês), Na (sódio), K (potássio), Ca (cálcio), Mg (magnésio), P (fósforo), Co (cobalto), Cd (cádmio), Cr (cromo), Pb (chumbo), teor de vitamina C, conteúdo total de antocianinas, potencial antioxidante (DPPH, ABTS), cor instrumental no espaço de cor (CIE L*a*b*; CIE C*h* e XYZ. As imagens dos 10 tipos de farinhas comerciais de frutas foram obtidas por câmara digital sendo processadas em software desenvolvido conforme formas de programação para o estudo das imagens digitais. Outras características das farinhas comerciais de frutas foram provenientes de informações analíticas instrumentais: difratometria de Raios-X, espectroscopia na região de absorção no infravermelho, e estudo por termogravimetria. O teor de umidade para todas as farinhas comerciais de frutas estudadas apresentou-se abaixo de 15 % e a atividade de água (Aw) foi inferior a 0,5000 demonstrando que as farinhas apresentavam estabilidade microbiológica. O pH mostrou-se variável de acordo com características oriundas de cada fruta. Para o conteúdo de cinzas, observou-se variação de 1,93 % ± 0,8 (MA) a 6,53 % ± 0,14 (MR). O conteúdo de proteínas variou de 1,59 % ± 0,09 (MA) e 6,59 % ± 0,86 (MR). O maior conteúdo de fibra alimentar foi encontrado na farinha comercial de coco (9,40 % ± 1,98), porém, não diferiu estatisticamente da farinha comercial de laranja (7,63 % ±0,81). Para a (LA) destacou-se o conteúdo mineral de Ca (412,81 mg.100g-1 ± 86,12) enquanto que (MM) apresentou maior teor do mineral K (952,11 mg.100g-1 ± 35,11) e Zn (2,67 mg.100g-1 ± 0,62) para (CO). Os minerais Fe e P (10,96 mg.100g-1 ± 3,08 e 107,06 mg.100g-1 ±51,59, respectivamente) prevaleceram para (UV). Para a análise de vitamina C os resultados encontrados refletem sua instabilidade perante as condições de exposição a temperatura e luz, principalmente, sendo que, o maior teor encontrado foi para AÇ (0,061±0,01 mg.100g-1). Para a metodologia de DPPH a variação foi de 0,035 ± 0,029 a 0,921 ± 0,063 μMTE. g-1 para (UV) e (MR), respectivamente, e, pela metodologia de ABTS foi de 1,135 ± 0,257 e 12,730 ± 1,914 μM Trolox.g-1 para CO e LI, respectivamente. Quanto aos resultados de antocianinas o maior valor observado foi para (CO) (1,132 mg.100g-1) não diferindo estatisticamente das demais amostras analisadas. O conteúdo de antioxidantes, bem como, o conteúdo total de antocianinas apresentou-se relativamente baixo, provavelmente devido ao processamento e condições inadequadas de armazenagem de tais amostras. A análise de espectroscopia de absorção por infravermelho revelou semelhanças de grupos funcionais (OH, C-H, C-O, C-C, 6 C-OH, CH2 e amido) quando comparamos as farinhas comerciais de frutas e farinha de trigo comercial tipo 1. A análise de difração de Raios X possibilitou uma tentativa de atribuição de cristalinidade. Sendo classificadas em tipo A as farinhas comerciais de (AÇ, AM, BV e MR); Tipo B a (BV); Tipos C as farinhas comerciais de (UV, MA e MM); e, as farinhas de (MM, CO, LA e LI) foram classificadas no Tipo V. A análise termogravimétrica possibilitou resultados que remetem ao uso industrial das farinhas em estudo, para a produção de produtos de panificação, podendo ser aquecidas acima de 180 °C, sendo que, o evento de degradação com maior temperatura foi observado para (CO; 442 °C). Considerando as características de cor resultante para os diferentes espaços de canais de cor (L*, a*, b*; H, S, V; L, U, V e X, Y, Z) para cada farinha avaliada neste estudo os dados mostraram ser de propriedade intrínseca da fruta que as origina se estabelecendo um sistema médio de cor que indicou uniformidade de amostra nos diversos lotes individuais de cada farinha. E, ainda, uma análise estatística de correlação entre o comparativo de cor instrumental e a aplicação da tecnologia de imagem digital indicou ser possível estabelecer uma correlação positiva para o conjunto de pigmentos bioativos, em particular, os dados de antocianinas, exceto para (CO). Os parâmetros físico-químicos determinados no presente estudo foram eficientes na análise da qualidade técnica e do perfil nutricional das farinhas comerciais de frutas e demonstraram que podem ser uma alternativa para enriquecer a alimentação da população tornando-a mais saudável e equilibrada. / The diversity of fruits produced in Brazil constitutes an alternative of consumption when industrialized in the form of flour, becoming a source of dietary bioactive compounds, fiber and minerals. They can also be used as an ingredient in the development of new, healthier and gluten-free food products. The present work aimed at the characterization, the study of chemical composition and nutritional quality of commercial fruit flour, as well as the use of digital image technology to establish a comparison their coloring patterns. Ten different samples of commercial fruit flour were collected and they were açaí (AÇ), plum (AM), green banana (BV), coconut (CO), orange (LA), lemon (LI), apple (MA), papaya (MM), passion fruit (MR) and grape (UV), and for each type of flour, three different batches were evaluated. The measurement of parameters were performed in triplicate for moisture, water activity, fixed mineral residue, proteins, dietary fiber (duplicate), pH, minerals like Cu (copper), Fe (iron), Zn (zinc), Mn (manganese), Na (sodium), K (potassium), Ca (calcium), Mg (magnesium), P (phosphorus), Co (cobalt), Cd (cadmium), Cr (chromium), Pb (cead), vitamin C content, total content of anthocyanins, antioxidant potential (DPPH, ABTS), instrumental color in color space CIE L*a*b*; CIE C*h* e XYZ. The images were obtained by digital camera and processed in software developed according to forms of programming for the study of digital imaging. Other characteristics of commercial fruit flours were derived from instrumental analytical information: X-ray diffractometry, spectroscopy in the infrared absorption region and study by thermogravimetry. The moisture content for all commercial fruit flour studied was below 15 % and the water activity (Aw) was less than 0.5000, demonstrating that the flours presented microbiological stability. The pH was variable according to the characteristics of each fruit. For the ashes content, it was observed a variation from 1.93 % ± 0.8 (MA) to 6.53 % ± 0.14 (MR). The protein content varied from 1.59 % ± 0.09 (MA) to 6.59 % ± 0.86 (MR). The highest dietary fiber content was found in the coconut commercial flour (9.40 % ±1.98). Although, it did not differ statistically from the orange commercial flour (7.63 % ± 0,81). For (LA), the Ca mineral content (412.81mg.100g-1 ±86.12) was highlighted, while (MM) presented higher K mineral content (952.11mg.100g-1 ±35.11) and Zn (2.67 mg.100g-1 ± 0.62) for (CO). Fe and P minerals (10.96 mg.100g-1 ± 3.08 and 107.06 mg.100g-1 ± 51.59, respectively) prevailed for (UV). For the analysis of vitamin C, the results found reflect its instability in the conditions of exposure to temperature and light, mainly considering that the highest content found was for (AÇ) (0.061 ± 0.01 mg.100g-1). For the DPPH methodology, the variation was of 0.035 ± 0.029 to 0.921 ± 0.063 μMTE.g-1 for (UV) and (MR), respectively and, by the ABTS methodology was of 1.135±0.257 and 12.730 ± 1.914 μM Trolox.g-1 for (CO) and (LI), respectively. Regarding the anthocyanins results, the highest value was observed for (CO) (1.132 mg.100g), which did not differ statistically from the other samples analyzed. The antioxidant content as well as the total anthocyanin content was relatively low, probably due to inadequate processing and storage conditions of such samples. The analysis of infrared absorption spectroscopy revealed similarities of functional groups (OH, C-H, C-O, C-C, C-OH, CH2 and starch) when compared to commercial fruit flours and wheat flour type 1. The X-ray diffraction analysis enabled an attempt to assign crystallinity being classified in type A the commercial flours of 8 (AÇ, AM, BV and MR); Type B the commercial flour (BV). Type C the commercial flours of (UV, MA e MM); and the flours of (MM, CO, LA and LI) were classified as type V. The thermogravimetric analysis allowed results that refer to the use of these flours under study for a production of bakery products, which can be heated above 180 °C, and the highest temperature degradation event was observed for (CO; 442 °C). Considering the resulting color characteristics for the different color channel spaces (L*, a*, b*; H, S, V; L, U, V e X, Y, Z) for each flour evaluated in this study the data showed to be of intrinsic property of the fruit that originates them, establishing a medium color system that indicated sample uniformity in the several individual each batches of flour. Also, a statistical analysis of the correlation between instrumental color comparison and the application of digital imaging technology indicated that it is possible to establish a positive correlation with the bioactive compounds, especially anthocyanins, data except for (CO). The physicochemical parameters determined in the present study were efficient in the analysis of the technical quality and nutritional profile of commercial fruit flours and demonstrated that they can be an alternative to enrich the food of the population making it healthier and more balanced.

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