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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.
211

Identification of Compounds that Impact the Ready-to-drink Coffee Flavor Stability during Storage Using LC-MS Flavoromics

Lin, Hao January 2021 (has links)
No description available.
212

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.
213

Funkcionalne karakteristike smeša maltodekstrina i namenske masti kao komponenti niskoenergetskih masnih punjenja za konditorske proizvode / Functional characteristics of vegetablefat/maltodextrin gel blends as a component for low calorie confectionery fat fillings

Hadnađev Miroslav 19 April 2012 (has links)
<p>Masna punjenja predstavljaju grupu proizvoda koje se<br />koriste u konditorskoj i pekarskoj industriji. Kako ona<br />najče&scaron;će sadrže između 30-40% masti, teži se dobijanju<br />formulacija sa redukovanim sadržajem masti. To se<br />može postići zamenom dela masne faze uz upotrebu<br />zamenjivača masti, najče&scaron;će hidrokoloida koji imaju<br />osobine slične osobinama zamenjene masti.<br />Maltodekstrini i njihovi geli mogu se koristiti kao<br />zamenjivači masti. Oni predstavljaju produkte hidrolize<br />skroba koji su rastvorljivi u vodi, mogu da poseduju<br />osobine formiranja gela, imaju slične mazive osobine<br />kao i masti i blagi i neutralni ukus.<br />U ovom radu ispitivane su reolo&scaron;ke osobine različitih<br />maltodekstrina kao i sme&scaron;a namenske biljne masti i<br />rastovora/gela maltodekstrina u odnosu 9:1. Na<br />osnovu dobijenih rezultata utvrđeno je da su od svih<br />ispitivanih komercijalnih maltodekstrina,<br />maltodekstrini <em>01970 </em>i <em>N-Lite D</em> sa namenskom biljnom<br />masti davali stabilne sisteme. Stoga su maltodekstrini<br /><em>01970</em> i <em>N-Lite D</em> kori&scaron;ćeni za dalja istraživanja.<br />Namenska biljna mast zamenjivana je sa 15 i 20%<br />gelima maltodekstrina <em>01970</em> i <em>N-lite D</em> u tri različita<br />odnosa: 16,7% gela maltodekstrina i 83,3% namenske<br />biljne masti; 33,3% gela maltodekstrina i 66,7%<br />namenske biljne masti i 50% gela maltodekstrina i<br />50% namenske biljne masti. Određivane su reolo&scaron;ke<br />osobine metodom histerezisnog postupka,<br />viskoelastične osobine, kao i teksturne osobine<br />pripremanih sme&scaron;a. Dobijeni rezultati su ukazivali da<br />prisustvo maltodekstrinskih gela u sme&scaron;i sa<br />namenskom biljnom masti utiče na pad tiksotropnosti i<br />čvrstoće i povećanje prividnog viskoziteta i<br />viskoelastičnosti ispitivanih sistema. Sve sme&scaron;e<br />namenske biljne masti i gela maltodekstrina služile su<br />kao komponenta masne faze za pripremu masnih<br />punjenja sa smanjenim sadržajem masti. Povećanjem</p><p>zamene dela masne faze maltodekstrinskim gelima u<br />masnim punjenjima uzrokovalo je povećanje<br />tiksotropnosti i čvrstoće kao i promenu boje krajnjeg<br />proizvoda. Na osnovu senzorske ocene sprovedene od<br />strane iskusnog senzorskog panela i na osnovu testa<br />prihvatljivosti od strane netreniranih potro&scaron;ača,<br />najbolje ocenjena masna punjenja bila su ona kod kojih<br />je 5% masti zamenjeno maltodekstrinskim gelima.<br />Međutim, na osnovu rezultata testa prihvatljivosti<br />uočeno je da su i sistemi sa 15% zamene masti bili<br />senzorski prihvatljivi. Takođe je i na osnovu rezultata<br />sprovedenog upitnika na uzorku od 250 ispitanika<br />utvrđeno da su potro&scaron;ači (64,4%) zainteresovani za<br />konzumiranje konditorskih proizvoda sa smanjenim<br />sadržajem masti.</p> / <p>Confectionery fat fillings are products used in<br />confectionery and baking industry. They contain<br />approximately 30-40% of fat. Due to the high fat<br />content, fat fillings have considerable high caloric<br />value. Therefore, there is a trend to decrease fat<br />content in fat filling formulation. That can be achieved<br />by replacing the portion of the fat phase with fat<br />replacers, most often with hydrocolloids having<br />characteristics which tend to mimic properties of<br />replaced fat. Maltodextrins and their gels can be used<br />as potential fat replacers. Maltodextrins represent<br />starch hydrolysis products soluble in water. Also they<br />posses gel forming ability, spreading ability similar to<br />fats, and bland and non sweet taste.<br />Rheological properties of different types of<br />maltodextrins were examined. Also, blends prepared<br />with 90 % of vegetable fat and 10% of maltodextrin<br />solution/gels were rheologically characterised.<br />According to obtained results, it was found that among<br />all tested commercial maltodextrins,<em> 01970</em> and <em>N-Lite<br />D</em> built stable systems. Therefore, they were used in<br />further measurements.<br />Vegetable fat was partially replaced by 15 and 20% of<br /><em>01970</em> and <em>N-Lite D</em> maltodextrin gels in three different<br />ratios (16.66%, 33.33% and 50% respectively). Steady<br />shear, dynamic oscillatory measurements as well as<br />textural measurements were performed. The obtained<br />results indicated that the presence of maltodextrin gels<br />in blends with vegetable fat influenced the decrease of<br />thixotropy and hardness and increase of viscosity and<br />viscoelasticity of the tested systems. All maltodextrin<br />gel/vegetable fat blends were further used for</p><p>preparation of confectionery fat fillings. The increase in<br />the amount of fat reduction resulted in the increase of<br />thixotropy and hardness and change in colour of the<br />final product. According to sensory analysis performed<br />by trained sensory panel as well as by measurement of<br />product acceptance&ndash;preference performed by<br />untrained panellists (consumers), fat filling with 5% fat<br />reduction had the highest scores. However, according<br />to product acceptance&ndash;preference measurements it<br />was estimated that the final product with 15% fat<br />reduction was also sensory acceptable. The results of<br />survey performed on 250 participants showed that<br />consumers (64.4%) were interested in consuming low<br />fat confectionery product</p>
214

THE EFFECTS OF ELECTRON BEAM IRRADIATION AND SANITIZERS IN THE REDUCTION OF PATHOGENS AND ATTACHMENT PREVENTION ON SPINACH

Neal, Jack A. 2009 May 1900 (has links)
The effects of electron beam (e-beam) irradiation and sanitizers in the reduction of Escherichia coli O157:H7 and Salmonella counts and attachment prevention on spinach was studied. Survival of these pathogens in spinach was observed at multiple times and temperatures. Inoculated spinach was examined by confocal microscopy to determine attachment sites and internalization of these pathogens. To determine the effectiveness of sanitizers in reducing pathogen numbers, inoculated spinach was treated with L-lactic acid, peroxyacetic acid, calcium hypochlorite, ozone, and chlorine dioxide. Inoculated spinach was exposed to e-beam irradiation and tested for counts of both pathogens immediately after irradiation treatment to determine bacterial reduction, and at 2 day intervals over 8 days to determine effects of ionizing irradiation on pathogen survival. Respiration rates were measured on spinach exposed to e-beam. The effectiveness of e-beam irradiation on the microbiological and sensory characteristics of spinach was studied. For spinach samples stored at 4�C and 10�C for 8 days, E. coli O157:H7 survived and grew significantly in samples stored at 21�C for 24 h. Confocal microscopy images provided valuable information on the attachment sites and internalization of the pathogens on spinach. The greatest reduction by a chemical sanitizer was 55�C L-lactic acid with a 2.7 log CFU/g reduction for E. coli O157:H7 and 2.3 log CFU/g reduction for Salmonella. Each dose of e-beam irradiation significantly reduced populations of both pathogens. Respiration rates of spinach increased as irradiation treatment doses increased. Total aerobic plate counts were reduced by 2.6 and 3.2 log CFU/g at 0.7 and 1.4 kGy, respectively. Lactic acid bacteria were reduced at both doses but grew slowly over the 35 day period. Yeasts and molds were not reduced in samples exposed to 0.7 kGy whereas 1.4 kGy had significantly reduced counts. Gas compositions for samples receiving 0.7 and 1.4 kGy were significantly different than controls. Irradiation did not affect the objective color or basic taste, aromatic or mouthfeel attributes of spinach. These results suggest that low dose e-beam irradiation may be a viable tool for reducing microbial populations or eliminating E. coli O157:H7 and Salmonella from spinach with minimal product damage.
215

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.
216

Development of three microbiologically safe, sensory acceptable food products as possible supplements to the diet of undernourished children (5 – 6 years)

Lombard, Matthys du Toit 12 1900 (has links)
Thesis (Msc Food Sc (Food Science))--Stellenbosch University, 2008. / The physical and mental development of underprivileged children, living in developing countries, is detrimentally affected by the exposure to poverty, malnutrition and poor health. The aim of the present study was to determine the possible risk of nutritional deficiencies of children (aged 5 – 6 years) in a low socio-economic community in the Grabouw area of the Western Cape, South Africa. The nutritional status of the children was evaluated by using anthropometric measurements (weight and height). Furthermore, the dietary intake provided by the meals offered at the schools they attended (Agapé 1 and Agapé 2), was assessed using the school menus. The latter were analysed using the FoodFinder3® computer programme (Medical Research Council of SA, Tygerberg, South Africa). Three supplementary food products (biscuit, health bar and soy milk-based drink) were subsequently developed to address possible nutritional deficiencies. The microbial stability of the products was determined, after which sensory acceptability of all three products was determined using a consumer panel consisting of children (n = 51; M:F = 27:24; 5 – 6 years) from the mentioned schools within the low socio-economic community. Anthropometric results were in agreement with those found by the National Food Consumption Survey (NFCS) (1999) and the South African Vitamin A Consultative Group (SAVACG) (1995), with stunting found to be most prevalent (16%). Only 5% of the children were found to be underweight and none were found to be wasted. The developed biscuit and health bar was found to be microbiologically safe when stored for at least 30 d at 25° and 35°C respectively, and the soy milk-based drink for 7 d if stored at refrigeration temperatures (5°C). Concerning the sensory preference, no significant difference was found between the preference for any of the developed products by the males and the females. For the specific products the preference for the biscuit did not differ significantly from the health bar, nor did the health bar differ significantly from the soy milk-based drink, but the biscuit did differ significantly (p = 0.006) from the soy milk-based drink for preference. The biscuit was found to be the most preferred of the three products and the soy milk-based drink the least. The majority of the juvenile consumer panel (95%) found all three developed food products acceptable and could, therefore, be considered possible supplementary foods in a school nutrition programme. The aim of nutritional supplementation is to supplement the existing diet and in doing so ensuring a more ideal nutrient intake closer to what is recommended by the recommended dietary allowance (RDA). It is proposed that nutritional deficiencies should, however, not only be addressed by means of nutritional supplementation, but should also be assisted by the nutrition education of the parent/guardian so as help them to make informed nutritional choices and in doing so providing their children with the nutrients necessary for optimal mental and physical development.
217

Avaliação reologica e sensorial de doce cremoso produzido com soro de leite de cabra, leite de vaca e polpa de umbu. / Rheological and sensorial evaluation of creamy candy produced with goat's milk, cow's milk and umbu pulp.

SILVA, Maria do Socorro Santos da. 04 July 2018 (has links)
Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-07-04T18:26:45Z No. of bitstreams: 1 MARIA DO SOCORRO SANTOS DA SILVA - DISSERTAÇÃO PPGEA 2011..pdf: 14157353 bytes, checksum: 47a111bda295e4045aaaa1a85f1bd0c8 (MD5) / Made available in DSpace on 2018-07-04T18:26:45Z (GMT). No. of bitstreams: 1 MARIA DO SOCORRO SANTOS DA SILVA - DISSERTAÇÃO PPGEA 2011..pdf: 14157353 bytes, checksum: 47a111bda295e4045aaaa1a85f1bd0c8 (MD5) Previous issue date: 2011-09 / Capes / O leite de cabra oferece vantagem competitiva em relação ao leite de vaca, devido à sua melhor digestibilidade e por se prestar para a produção de queijos especiais de alto valor comenjial. A produção de queijo gera soro, em grandes quantidades, como subproduto. O soro é um alimento rico em proteínas de alto valor biológico mas sofre com a baixa aceitabilidade em virtude do sabor e do odor, ainda mais quando derivado de leite caprino. A estratégia economicamente mais viável para o aproveitamento do soro de leite caprino é a incorporação de ingredientes que mascarem ou anulem seu sabor, com ganhos maiores se forem usados ingredientes locais, como a polpa de umbu. Neste trabalho se utilizaram soro de leite de cabra, leite de vaca e polpa de umbu na produção de doces cremosos. As amostras foram elaboradas com a mistura de soro de leite de cabra e leite de vaca, na proporção de 1:1, sacarose e polpa de umbu variando nas concentrações de 10, 15 e 20%. A polpa de umbu e os doces foram avaliados quanto ao pH, teor de sólidos solúveis totais, ácido ascórbico, acidez total titulável, cinzas, açúcares redutores, proteínas totais, lipídios, densidade, atividade de água e cor. Os doces foram estudados quanto ao comportamento reológico e submetidos a avaliações sensoriais. Nas análises sensoriais os provadores avaliaram as amostras por meio de escala hedônica na qual julgaram os atributos cor, aonsistência, sabor, doçura, odor, aparência, acidez e intenção de consumo. Os dados experimentais utilizados no estudo do comportamento reológico foram coletados em viscosímetip Brookfíeld, nas temperaturas de 20, 30 e 40 °C, e os modelos de Ostwaldde-Waelle (Leil da Potência), Casson, Herschel-Bulkley e Mizrahi-Berk foram ajustados aos reogramas A polpa de umbu apresentou-se muito ácida. A amostra com menor quantidade de polpa de umbu obteve a melhor aceitação. Todos os doces apresentaram comportamentoi pseudoplástico; as viscosidades aparentes diminuíram com o aumento da velocidade de lotação e as viscosidades diminuíram com o aumento da temperatura. Os modelos reológicos da Lei-da-Potência, Herschel-Bulkley, Casson e Mizrahi-Berk, se ajustaram bem aos dados de tensão de cisalhamento e taxa de deformação, e o modelo de Mizrahi-Berk n sultou nos melhores ajustes / Goat milk offers a competitive advantage over cow's milk due to its better digestibility and suitability in the production of high-value cheeses. Large-scale production of cheese generates whey as a by-product. Whey is rich in proteins with high biological value, but low acceptability because of its unpleasant odor and taste, especially when derived from goat's milk. The most economically viable economic strategy for goat milk whey is to incorporate ingredients that mask or neutralize its taste, with added gains if local ingredients such as umbu pulp are used. In this study goat milk whey, cow's milk and umbu pulp were used in the production of sweet creamy desserts. Samples were elaborated with a mixture of goat milk whey and cow's milk at a ratio of 1:1, plus sucrose and umbu pulp at concentrations of 10, 15 and 20%. Umbu pulp and the sweets were assessed for pH, soluble solids, ascorbic acid, titratable acidity, ash, reducing sugars, total proteins, lipids, density, water activity and color. Creamy sweet desserts were studied for rheological behavior and submitted to sensory evaluation. In sensory analyses judges assessed samples according to the hedonic scale, judging color, consistency, taste, sweetness, odor, appearance, acidity and intention to consume. Experimental data used in the study of rheological behavior were collected in a Brookfield viscometer, at temperatures of 20, 30 and 40 °C, and Ostwald-de-Waelle (Power Law), Casson, Herschel-Bulkley and Mizrahi-Berk models were fit to rheograms. Umbu pulp exhibited considerable acidity. The sample with the lowest amount of umbu pulp was the most accepted. All the creamy sweet desserts displayed pseudoplastic behavior; apparent viscosities decreased with an increase in rotation speed; and viscosities decreased with an increase in temperature. Power Law, Herschel-Bulkley, Casson and Mizrahi-Berk rheological models fit shear stress and strain rate data well, with the Mizrahi-Berk model resulting in the best fit.
218

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.
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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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Qualidade e atividade antioxidante da polpa e desenvolvimento de bebidas de pitanga (Eugenia uniflora, L.). / Quality and antioxidant activity of pulp and development of Surinam cherry beverages

Aline Braga da Silva 30 January 2012 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Eugenia uniflora L. à um fruto tropical muito apreciado pelo seu sabor e aroma exÃticos. A pitangueira pertence à famÃlia das mirtÃceas, sendo facilmente cultivada em regiÃes de clima tropical e subtropical. O fruto apresenta coloraÃÃo que varia do laranja ao roxo, devido à presenÃa de pigmentos como carotenÃides e antocianinas. A pitanga possui um alto potencial econÃmico, no entanto, à muito vulnerÃvel à depreciaÃÃo quando madura, tornando-se necessÃrio a formulaÃÃo de produtos, visando um melhor aproveitamento tecnolÃgico. Dessa forma, este trabalho teve como objetivo avaliar as caracterÃsticas quÃmicas, fÃsico-quÃmicas, compostos bioativos e atividade antioxidante das polpas de pitanga de coloraÃÃes vermelha e roxa, desenvolver diferentes bebidas (refresco, nÃctar e suco tropical adoÃado) com polpa de pitanga roxa e avaliar suas caracterÃsticas microbiolÃgicas, sensoriais, quÃmicas e fÃsico-quÃmicas, bem como sua atividade antioxidante e principais compostos bioativos. As polpas de pitanga vermelha e roxa apresentaram caracterÃsticas quÃmicas e fÃsico-quÃmicas diferentes para todos os parÃmetros avaliados, exceto para a coordenada a*. A polpa roxa apresentou os maiores teores de compostos bioativos, exceto para a determinaÃÃo de carotenÃides totais, onde nÃo foi constatada diferenÃa significativa entre as polpas. Foram formuladas bebidas com teor de sÃlidos solÃveis fixados em 11ÂBrix e teor de polpa de 15% (refresco), 25% (nÃctar) e 35% (suco tropical adoÃado). O refresco, o nÃctar e o suco tropical apresentaram diferentes concentraÃÃes de vitamina C, carotenÃides totais, antocianinas totais, polifenÃis extraÃveis totais e atividade antioxidante total, sendo estes valores maiores na bebida com maior concentraÃÃo de polpa (suco tropical adoÃado). O nÃctar e o suco tropical apresentaram valores de acidez e aÃÃcares totais dentro dos limites fixados pela legislaÃÃo brasileira. As bebidas apresentaram condiÃÃes higiÃnico-sanitÃrias satisfatÃria. A avaliaÃÃo sensorial revelou que o refresco, o nÃctar e o suco tropical adoÃado apresentaram escores mÃdios entre a faixa de aceitaÃÃo e indiferenÃa para os testes de aceitaÃÃo e intenÃÃo de compra, com maiores notas para o nÃctar e o refresco. As maiores mÃdias atribuÃdas Ãs bebidas foram para os atributos cor e aparÃncia. A intenÃÃo de compra das bebidas parece ter sido influenciada pelos atributos sabor e doÃura. / Eugenia uniflora L. is a tropical fruit appreciated for its exotic flavor. Belonging to Myrtaceae family. It is cultivated easily in regions of tropical and subtropical climates. The fruits have colour ranges from orange to purple, due to the presence of pigments such as carotenoids and anthocyanins. The Surinam cherry has a high economic potential, but ripe fruits are vulnerable to depreciation, thus, it is necessary to formulate products with cherry pulp to stimulate a better use of technological fruit. Thus, the purpose of this study was evaluate the chemical and physicochemical characteristics in the pulps of red and purple colour and its antioxidant activity and content of bioactive compounds, develop different beverages (refreshment, nectar and tropical juice) with purple pulp, evaluate the microbiology, sensory, chemical and physicochemical characteristics, and its antioxidant activity and content of bioactive compounds. The pulps showed chemical and physicochemical characteristics different, excepting colour parametric a*. The purple pulp shower higher values of bioactive compounds, save the evaluation of carotenoids, that showed difference no significant. Was developing beverages with 11ÂBrix and 15% of pulp (refreshment), 25% de pulp (nectar) and 35% de pulp (tropical juice). The refreshment, nectar and tropical juice showed different values of vitamin C, carotenoids, anthocyanins, polyphenols and antioxidant activity, with higter values for the beverage with higter content of pulp (tropical juice). The tropical juice and nectar had values of acidity and total sugars within the limits established by Brazilian legislation. The fruit beverages showed hygienic and sanitary conditions. The sensory evaluation revealed that the refreshment, nectar and tropical juice had mean scores between the range of acceptance and indifference to the acceptance tests and purchase intent. The sensory parameters colour and appearances given the higher means. The attribute flavor and sweetness influenced the purchase intent.

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