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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.
151

Evaluation of Dechlorinating Agents and Disposable Containers for Odor Testing of Drinking Water

Worley, Jennifer Lee 08 September 2000 (has links)
As the bottled water trend continues to rise across the nation, drinking water utilities have become more concerned with ensuring consumer satisfaction of their product. Although public water supplies are safeguarded by regulations, aesthetically unappealing taste-and-odor problems have led consumers to search for alternative water sources, such as bottled water or tap water processed by point-of-use filters. Consequently, taste-and-odor monitoring has become important to the drinking water industry. Because many utilities use chlorine to disinfect the water, chlorine odor often masks other more subtle odors that may eventually cause consumer complaints. As treated water travels from the water treatment plant to the consumer, chlorine residual diminishes and may reveal a water's naturally less-pleasing odors. Consequently, odor monitoring at the water treatment plant, where chlorine concentrations are at a peak, may not identify potential displeasing smells. Proper evaluation of these odor-causing substances requires that the chlorine odor first be eliminated before evaluating any remaining odors. Dechlorinating agents can remove chlorine, but some will produce other unwanted odors or even remove certain odorous compounds. This research describes the efficiency of several of these agents (ascorbic acid, hydrogen peroxide, oxalic acid, sodium nitrite, and sodium thiosulfate) in dechlorinating chlorinated solutions of the earthy-smelling compound geosmin and musty-smelling MIB. Interfering odors in reusable containers pose another problem in drinking water odor analysis. The most common odor-analysis methods (TON and FPA) involve the use of glass flasks, which often either develop chalky odors or have persistent lingering odors from previous evaluations. Furthermore the glass flasks break easily and are difficult to clean. This research also evaluates the suitability of four types of disposable plastic containers for odor analyses. / Master of Science
152

The Sensory and Analytical Analyses of Nonfat Milk Formulations: Stability to Light Oxidation and Pasteurization

Powell, Jodi 25 September 2001 (has links)
Sweet cream liquid buttermilk and skimmed milk ingredients were heat processed and/or exposed to fluorescent light to determine changes in potential flavor compounds. Solid phase microextraction-gas chromatography/flame ionization detection was used to analyze the concentrations of the volatile compounds (2-butanone, 2-pentanone, acetaldehyde, diacetyl, hexanal, methyl sulfide) found in the two components. Pasteurized unoxidized skimmed milk had measurable levels of 2-butanone, acetaldehyde, and diacetyl. Pasteurization of skimmed milk increased concentration of 2-pentanone and methyl sulfide to measurable levels. However only 2-butanone and acetaldehyde were detectable in oxidized skimmed milk. All liquid buttermilk ingredient treatments had measurable concentrations of 2-butanone, 2-pentanone, and acetaldehyde. Pasteurization of unoxidized liquid buttermilk increased the concentration of diacetyl and hexanal to measurable levels whereas oxidized buttermilk, both pasteurized and unpasteurized, had measurable levels of hexanal and methyl sulfide. Nonfat (.3%) dairy beverages were formulated using the same components to determine if the volatiles in liquid buttermilk might enhance the flavor of nonfat milk. Triangle tests and hedonic tests were performed on the nonfat formulations to determine their overall difference and overall acceptance. There was no significant difference between formulations. / Master of Science
153

Hur beskrivs sensoriska egenskaper inom deskriptiv analys? : En kvantitativ tvärsnittstudie av artiklar publicerade 1974-2019 / Sensory attribute description in descriptive analysis : A quantative cross sectional study of articles published 1974-2019

Apelman, Linnea January 2021 (has links)
Bakgrund Deskriptiv sensorisk analys (DSA) syftar till att beskriva sensoriska egenskaper (attribut) hos livsmedelslprodukter. En bedömarpanel analyserar ett produktprov genom att identifiera, namnge och mäta intensiteten hos ett antal attribut. Syfte Syftet med undersökningen var att studera hur attribut identifieras, beskrivs och presenteras inom vetenskaplig tillämpning av DSA. Metod Sjuttiofyra artiklar, publicerade i vetenskapliga tidskrifter mellan 1974 och 2019, analyserades kvantitativt med hjälp av deskriptiv statistik. Sjutton variabler användes för datainsamling. Samband mellan variablerna analyserades med hjälp av statistiska tester. Resultat Av artiklarna var 96 % publicerade i tidskrifter utan specifik inriktning mot sensorisk analys. I två tredjedelar av artiklarna tillämpades generisk deskriptiv analys (GDA). I fler än hälften av artiklarna avvek panelen från vad som rekommenderas kring bedömarantal eller tid för träning. I snitt användes 1,4 ord för namngivning av attributen. I hälften av artiklarna definierades inte attributen. I två tredjedelar av artiklarna presenterades inte några referensprodukter för att illustrera skalstegen. I tre fjärdedelar av artiklarna presenterades attributen i metodbeskrivningen. Meddelandelen substantiv var 68,2 % och 31 % adjektiv. En måttlig negativ korrelation mellan andelen substantiv och tiden för träning av bedömarpanelen var statistiskt signifikant. Slutsats I många vetenskapliga studier utförs DSA utan att gällande rekommendationer kring bedömarpanelen följs. I artiklar publicerade i vetenskapliga tidskrifter presenteras attributen inprecist nog att ifrågasätta användbarheten hos resultaten. Att ge den kvalitativa delen av undersökningen, identifiering och namngivning av attributen, status resultat skulle kunna öka intresset för att definiera attributen och illustrera skalstegen, vilket är en förutsättning för att tolka det kvantitativa resultatet (intensitetsmätningen) på ett meningsfullt sätt. / Background Descriptive sensory analysis (DSA) aims to describe the sensory attributes of food products. A panel of assessors analyze a sample of the product to identify and name a set of attributes and estimate their intensity. Objective The aim of the study was to research how attributes are identified, described and presented in the scientific use of DSA. Method By using descriptive statistics, 74 articles published in scientific journals between 1974 and 2019 were analyzed quantitatively. Data collection was conducted using 17 variables. Correlations between variables and differences between groups were analyzed using statistical tests. Results Of the articles 96 % were published in non-sensory-specific journals. Generic descriptive analysis (GDA) was used in two thirds of the articles. In more than half of the articles the number of assessors, or the time spent on assessor training, differed from what is recommended. An avarage of 1.4 descriptive words were used to name each attribute. In half of the articles no definitions of the attributes were given. In two thirds of the articles no reference products were presented to illustrate the attributes or different points of the scale. In three quarters of the articles the attributes were presentet in the section of method description, and not the results. The avarage share of nouns was 68.2 % and 31 % adjectives. A moderate negative correlation between the share of nouns and the time spent on panel training was significant. Conclusion Sometimes DSA is used without panel recommendations being followed. There are scientific articles where the sensory attributes are presented vaguely enough to question the usability of the results. To interperet naming of the sensory attributes as a qualitative results could motivate a more defined presentation, which would benefit the quantitative result (intensity assesment) by explaining what is meassured.
154

Physico-chemical properties, and water and oil uptake characteristics of novel, soy-based snacks processed using extrusion

Kodavali, Swathi Sree January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Sajid Alavi / Extrusion processing and frying are the two most commonly used methods to produce savory snacks. These snacks are mostly starch based and also contain high amounts of fat. Snacking percentage has increased drastically over the past few decades causing many health problems like obesity, hypertension and cardiovascular diseases. The overall objective of this study was to develop novel soy based savory snack that are high in protein and has less fat using both extrusion processing and frying. In the first part of this study both defatted soy (25-75%), wheat flour, monoglycerides (0.375 & 0.75%) and sodium bicarbonate (0 and 0.5%) were used to produce dense extrudates, which mimic the shape of lentils using pilot scale twin screw extruder. The extrudates were soaked in water and fried in corn oil to produced savory snacks. Soy influenced the water absorption during soaking and oil uptake during frying. The water uptake and % fat decreased with increase in soy and the amount of water uptake influenced the % fat absorption in the product. No significant differences were observed in overall acceptability and to summarize the increased protein and dense structure of the products challenge the texture of the products. In the second part of this research, dynamics of water and oil uptake were studied to see the role of texture modifiers like soy protein isolate (4, 8, & 12%), calcium bicarbonate (0.2, 0.4 & 0.6%) and pregelatinized wheat starch (4, 8, & 12%) on texture, water and oil uptake. Descriptive sensory analysis was conducted to study the sensory attributes of the products. Water holding capacity is influenced by the level of % starch addition and the degree of starch degradation during processing. Oil uptakes correlates to that of WHC and is also affected by the degree of gelatinization and crust formation. Degree of starch gelatinization, oil uptake and oil and starch matrix interactions had an impact on hardness. Among SPI, CaCO3 and PGWS, PGWS lowered the product hardness followed by SPI and CaCO3. Descriptive sensory results are similar to experimental results with PGWS samples having lower initial or substantial hardness and more oxidized or heated oil aroma and flavor.
155

Contribution à l’étude et l’évaluation de la qualité et du confort au porter de produits confectionnés : Cas de la chemise homme / Contribution to the study and to the evaluation of the quality and the wearing comfort of garment products : Case of man shirt

Abbas, Wedian 16 September 2014 (has links)
Il y aujourd'hui a un intérêt croissant pour la relation entre les matériaux textiles et les êtres humains, et le confort est devenu beaucoup plus important pour les consommateurs au cours des dernières années.Pour cette raison notre travail est basé sur l’optimisation de la caractérisation du confort (confort au porter) pour des étoffes utilisées principalement pour fabriquer des chemises d’homme.A cet effet, plusieurs méthodes ont été utilisées :- Analyse instrumentale : nous avons utilisé des méthodes instrumentales habituelles afin de mesurer les propriétés : - mécaniques en (cisaillement, flexion, compression, frottement et état de surface) ainsi - thermique (sensation chaud-froid)Physique (perméabilité à l'air, absorption capillaire...etc.).- Analyse sensorielle: nous avons utilisé à cet effet, le panel sensoriel développé au sein du LPMT depuis 2001. Elle a permis de réaliser l'évaluation quantitative descriptive des produits sélectionnés et fournis par notre partenaire industriel. - Analyse hédonique: Evaluation du confort ressenti de la chemise confectionnée grâce à une enquête « consommateurs ».- Etude marketing Evaluation de l’influence de la notion de « marque » ou une mention « traitement innovant » sur l’évaluation du confort des étoffes utilisée en comparaison avec l’évaluation du confort par le toucher et le touche-vue. - Etude patronage : Optimisation du processus de « développement produit » en prenant en compte la satisfaction attendue du consommateur en particulier en termes de confort. Elle consiste en l’étude des relations entre les paramètres physique du patron et les caractéristiques mécaniques des tissus utilisés obtenues dans la première partie de cette recherche.Cette combinaison d’analyse nous a permet de proposer une nouvelle procédure de conception de produit confectionné prenant en compte le confort et les attentes du consommateur et en particulier dans le cas du développement de « chemise d’homme ». / Nowadays there is a growing interest in the relation between the textile materials and human being, and the comfort has become much more important to consumers. For this reason our work is based on optimization of the characterization of the comfort (wearing comfort) in relation with the fabrics used to produce men’s shirts. To achieve this study, several methods of analysis have been used:- Instrumental analysis: To measure mechanical properties, classical characterization tools have been used to measure:Mechanical properties (shear, bending, compression, friction and surface) Thermal comfort (warm-cool sensation)Physical properties (air permeability, capillary absorption ... etc. . .). - Sensory analysis: Thanks to the trained panel that has been developed and used since 2001 at LPMT, the quantitative descriptive evaluation of the selected product using has been carried out.- Hedonic Analysis: Evaluation of comfort by consumer surveys.- Marketing study: To investigate the influence of the brand or some innovative mention like “anti-sweat ring” on the comfort evaluation of fabrics, in comparison with the evaluation realized by touching or by touching-seeing.- Blocks analysis: it aims to optimize the processes of product development, taking in consideration the requested consumer’s satisfactions especially in term of comfort. It consists of studying the relation between the block parameters and the mechanical properties of the fabric used to produce the product.This combination of analysis allows us to have a new conception procedure for the development of clothing product taking in account the comfort and the consumer’s expectation particularly in the men shirt development.
156

Desenvolvimento e avaliação de nanoemulsão cosmética à base de óleos naturais de urucum (Bixa orellana, L) e café verde (Coffea arabica, L) / Development and evaluation of a cosmetic nanoemulsion, prepared using annatto (Bixa orellana, L) and green coffee (Coffea arábica, L) oils

Agostinho, Luciana Carvalho 07 April 2017 (has links)
Nanoemulsões são dispersões coloidais caracterizadas por apresentarem glóbulos de tamanho nanométrico, o que lhes confere estabilidade cinética e habilidade em promover melhora na absorção de substâncias ativas pela pele. A hidratação adequada e a proteção contra as agressões do ambiente são pontos críticos para manutenção de uma pele saudável. A riqueza da biodiversidade brasileira apresenta-se como imensurável fonte de matérias primas e os óleos vegetais são um grande exemplo, por apresentarem compatibilidade e conferir emoliência e oclusividade à pele. O óleo de urucum é amplamente utilizado pela indústria de alimentos e cosmética, atóxico e tem propriedades antioxidantes, sendo utilizado como adjuvante de filtros solares. O óleo de café é rapidamente absorvido pela pele e apresenta ação antioxidante e estimulante da síntese de colágeno e elastina. Neste projeto estudamos a formulação de uma nanoemulsão aditivada, pelo método de inversão de fases, contendo óleo de urucum e óleo de café, com o objetivo de conferir ao produto final propriedades hidratantes, antioxidantes e auxiliares na proteção contra os efeitos nocivos da radiação solar. A nanoemulsão aditivada mostrou-se estável e com características desejáveis como boa capacidade oclusiva, valor de pH compatível com a pele e perfil de viscosidade pseudoplástico. Submetida a análise sensorial por painel treinado, foi considerada aprovada, quando comparada ao produto comercial / Nanoemulsions are colloidal dispersions characterized by their nanometric particle size that grant kinetic stability and improves the topical delivery of active substances. Proper hydration and protection from environmental aggression are critical conditions for healthy skin. Brazilian biodiversity is an immeasurable source of raw material; vegetable oils are a good example of that, due to skin compatibility and their ability to sooth, grant occlusion and skin glow. Annatto oil is widely used in food and cosmetics industries for its lack of toxicity and antioxidant properties as well as adjuvant to sunscreen. Green coffee oil shows fast skin absorption, antioxidant properties, and promotes collagen and elastin synthesis. The aim of this project was to study the formulation of a nanoemulsion with Annatto and Green coffee oils, plus additives, to grant the final product hydration, antioxidant and sunscreen adjuvant characteristics. The product showed stability and desirable characteristics, such as occlusive capacity, skin-compatible pH value and pseudoplastic viscosity profile. Submitted to sensory analysis, the additivated nanoemulsion showed good acceptability by a trained panel when compared to a commercial product
157

Caracterização da fruta do Jacaratia spinosa e processamento do doce de jaracatiá em calda com avaliação da estabilidade / Caracterization of the Jacaratia spinosa fruit and processing of the jaracatiá compote with stability avaluation

Prospero, Evanilda Terezinha Perissinotto 30 September 2010 (has links)
O presente trabalho teve como objetivo caracterizar a fruta in natura do Jacaratia spinosa (AUBL) A.DC a partir das amostras de 3 lotes analisados em triplicata, quanto aos parâmetros físicos: peso, medida, densidade, textura, cor da casca, cor da polpa, atividade de água; químicos: pH, teor de sólidos solúveis (TSS), acidez titulável (AT), carotenóides, ácido ascórbico, açucares totais e redutores, fibras solúveis e insolúveis, minerais; composição centesimal; valor calórico total (VCT). O segundo objetivo foi desenvolver o doce de jaracatiá em calda da fruta in natura e fruta congelada, verificando-se sua estabilidade no período de 90 dias. Também foi objetivo oportunizar espaço para comercialização da fruta e doce como produtos ecogastronômicos definidos pela Slow Food, e que, a fruta através da tradição de seu doce na forma de compota possa promover sustentabilidade para as comunidades e o ecossistema em que está inserida. O jaracatiá é uma árvore do bioma Mata Atlântica em risco de extinção em muitos estados brasileiros e pouco se conhece da fruta. As amostras foram coletadas nos municípios de Brotas, São Pedro e Santa Maria da Serra, no Estado de São Paulo- Brasil. Para avaliação da estabilidade do doce realizaram-se análises de pH, acidez titulável (AT), teor de sólidos solúveis (TSS), atividade de água (aw) e cor; microbiológicas (bolores e leveduras); e sensoriais (aparência, odor, sabor, textura, intenção de compra). Entre as regiões de coleta, a amostra de Brotas se caracteriza pela textura e comprimento, a amostra de São Pedro, pela cor (hue) e a amostra de Santa Maria da Serra pela luminosidade da casca, ácido ascórbico, atividade de água e teor de sólidos solúveis. O jaracatiá possui baixo valor calórico (VCT) e os altos teores de fibras se destacam, sendo muito superiores aos do mamão. O jaracatiá pode ser considerado fonte de fibras; salientam-se ainda os teores de cálcio, magnésio e potássio. Para o doce, a análise sensorial mostrou a preferência do produto para as amostras de Brotas e São Pedro, por terem sido processadas com frutas em maior grau de maturação. Houve 100% de aceitabilidade para os dois tratamentos. / The objective of the present work has to characterize the fruit in natura of the Jaracatia spinosa (AUBL) A. DC , from 3 samples of 3 lots analyzed in triplicate, regarding its physical parameters: weight, length, width, density, texture, color of the fruit peel, color of the pulp, water activity; chemical: pH, total soluble solids, titratable acidity, carotenoids, ascorbic acid, total sugars and reductive sugars, soluble and insoluble fibers, minerals; proximate composition: moisture, ash, proteins, lipids, available total carbohydrate and total caloric value. The second objective has developed from two variables: fruit in natura and frozen fruit, verifying its stability in a period of 90 days. The goal was also to widen the space for the commercialization of the fruit and its compote as ecogastronomic products, as defined by Slow Food, and that the fruit, through the tradition of its compote, promote sustentability for the communities and the ecosystem in which it is inserted. The Jaracatia spinosa (AUBL) A.DC is a tree of the Mata Atlântica biome in risk of extinction in several Brazilian states and little is known about the fruit. The samples were collected in the cities of Brotas, São Pedro and Santa Maria da Serra, in the São Paulo State from Brasil. For the avaluation of the stability of the compote were realized chemical analysis of pH, titratable acitity total soluble solids, water activity and color; microbiological (mold and yeast); and sensory (apearance, odour, taste, texture, intention of buying). Among the regions, the Brotas sample caracterizes for the parameters of texture and length, the São Pedro sample, for the hue and the Santa Maria da Serra, for the peel luminosity, ascorbic acid, water activity and soluble solids It contains a low total caloric value and high concentration of fibers, very superior to those of the papaya, characterizing the jaracatiá as a fiber source; we also notice the calcium and magnesium concentration and potassium. For the compote, the sensory analysis showed the preference of the product Brotas and São Pedro samples, because they were processed with fruits in higher degree of ripeness. There was 100% acceptability for both treatments.
158

Desenvolvimento do produto de conveniência Quenelle de tilápia (Oreochromis niloticus) / Product development of convenience quenelle tilapia (Oreochromis niloticus)

Angelini, Maria Fernanda Calil 17 November 2010 (has links)
Para o desenvolvimento de um novo produto, busca-se atender a necessidade da indústria, do mercado e do consumidor, nos parâmetros qualidade, conveniência e com valor nutritivo que remeta à boa saúde. Com o objetivo de desenvolver o coproduto Quenelle de tilápia iniciou-se a etapa criativa de elaboração e a seguir, estabeleceu-se o processo do estudo de vida útil, a fim de definir a validade do produto, com base nos parâmetros físico-químico, microbiológico e sensorial. Na primeira etapa, 11 formulações foram testadas e a partir da avaliação destas, outras 4 formulações foram desenvolvidas e avaliadas através de análise sensorial de preferência por ordenação, resultando na formulação eleita composta dos seguintes ingredientes: Minced, gordura vegetal, cebola desidratada, proteína isolada de soja, tempero Hondashi, salsa desidratada, urucum e sal. O teste de vida útil foi realizado no período de 120 dias, sendo as análises físico-químicas, microbiológicas e sensoriais realizadas a cada 30 dias. O produto Quenelle contém, em média, 69,63 g/100g de umidade, 2,46 g/100g de cinza, 8,51 g/100g de lipídeos,15,18 g/100g de proteína e 4,23 g/100g de carboidrato, apresentando valor de TBARS de 1,12 mg malonaldeído/kg e pH de 6,5. Quanto às análises microbiológicas os valores foram os seguintes: para psicrotróficos 3,24 log UFC/g; coliformes termotolerantes, <3,0 NMP/g; coliformes totais, 3,6 NMP/g; Staphylococcus aureus, <10 NMP/g e ausência de Salmonella em 25/g. O produto foi embalado em dois tipos de embalagem, pouche de polietileno com zíper (QA) e embalagem de polietileno complementada com caixa de cartão parafinado (QB). A rotulagem, para a porção de 40g de Quenelle, mostrou os seguintes valores: 59 kcal, 2,1g de carboidrato, 5,64g de proteína, 2,84g de gorduras totais, 1,53g de gordura monoinsaturada, 0,64g de poliinsaturada, 0,04g de ômega 3 e 0,56g de ômega 6, 1,06g de gordura saturada, 0,39 de gordura trans, 0,63 mg de ferro, 271 mg de sódio, 10 UI de vitamina A, 3,03 mcg de retinol. A análise sensorial foi realizada através de um teste de avaliação de atributos, aparência (úmida, homogênea, impressão global), aroma (característico de peixe, característico do produto), textura (maciez, suculência, elasticidade), gosto (sal) e sabor (característico de peixe, condimento, off flavor de barro, off flavor de geladeira). Os valores médios dos atributos avaliados de Quenelles de tilápia em diferentes embalagens (QA e QB), durante o armazenamento, não apresentaram diferença significativa (p>0,05), bem como a interação tratamento versus provador. Quando se avaliou as médias dos atributos sensoriais nos dias de armazenamento e para as diferentes embalagens, pôde-se notar que houve diferença significativa (p<0,05) para todos os atributos, com exceção da maciez. Os provadores tiveram procedimento considerado significativo, para alguns atributos, como aparência úmida, aroma característico de peixe e do produto, e sabor de barro e de geladeira; com isso, algumas interações dias versus provador foram significativas, tais como aparência úmida, aroma característico de peixe e do produto, maciez, suculência, elasticidade, sabor característico de peixe, de condimento, de barro e de geladeira, e gosto de sal, exceto a aparência homogênea. / To develop a new product, we seek to meet the needs of industry, market and consumer. In questions, quality and convenience, offering food with nutritional value referring to good health. The objective was developing the co-product Quenelle of tilapia and began the creative phase of development. Created formulation, settled the case study of life in order to determine the shelf life of the product, based on physicalchemical, microbiological and sensory parameters. In the first stage, 11 formulations were tested by sensory analysis and preference ordering, resulting in the final formulation containing the following ingredients: minced, vegetable fat, dehydrated onion, soy protein isolate, Hondashi seasoning, salt and annatto. The shelf life test was carried out in 120 days, and the physical-chemical, microbiological and sensory testing performed every 30 days. The results were obtained for moisture 69.63 g.100g-1; ash 2.46 g.100g-1; fat, 8.51 g.100g-1, protein 15.18 g.100g-1and, 4.23 g.100g-1 carbohydrate. The value of TBA was 0.45 mg malonaldehyde / kg and pH was 6.5. As microbiological analysis the values were to psicotrophic 3.24 log CFU.g-1 / g, fecal coliform, <3.0 MPN.g- 1, total coliforms, 3.6 MPN.g-1, Staphylococcus aureus, <10 MPN.g-1and absence of Salmonella 25 / g. The product was packaged in two types of packaging, polyethylene pouch with zipper (QA) and polyethylene packaging more waxed cardboard box (QB). The label for the serving of 40g quenelle was: 59 kcal, 2.1 g of carbohydrate, 5.64 g of protein, 2.84 g of total fat, 1.53 g of monounsaturated fat, 0.64 g of polyunsaturated, 0.04 g of omega 3 and 0.56 g of omega 6, 1.06 g of saturated fat, 0.39g trans fat, 0.63 mg of iron, 271 mg of sodium, 10 IU of vitamin A, 3.03 mcg of retinol. Sensory analysis was performed using a test evaluation of attributes with six trained testers, where the samples showed no significant difference (p> 0.05) during storage. Sensory analysis was performed by an evaluation test attributes of appearance (moisture, homogeneous, general impression), aroma (fish characteristic, typical of product), texture (tenderness, juiciness, elasticity), taste (salt), flavor (fish characteristic, spices, mud off flavor, storage off flavor) with six trained testers. The average values of the attributes evaluated Quenelles tilapia in different packages (QA and QB), during storage, showed no significant difference (p > 0.05). The taster versus treatment interaction was not significant (p> 0.05). When assessing the means of sensory attributes in the days of storage, also considering the average values for all days (0, 30, 60, 90 and 120) of storage, besides the different packages (QA and QB), it was noted that significant differences (p <0.05) for all attributes except tenderness. Tasters procedure were considered significant (p <0.05) for some attributes, such as moisture appearance, aroma of fish and product, and taste of mud and storage; with it, some days versus tester interactions were significant (p <0.05), such moisture, aroma of fish and product, tenderness, juiciness, elasticity, flavor of fish, spices, mud, storage and salt, except the appearance homogeneous. The treatments interaction versus days of storage, just taste of storage showed significant difference (p <0.05).
159

Utilização do palmito basal de pupunha em alternativa ao palmito foliar, visando aumentar o aproveitamento da palmeira Bactris gasipaes / Use of the basal palm of peach palm in alternative to the foliaceous palm, to increase the use of the palm tree Bactris gasipaes

Silva, Paula Porrelli Moreira da 02 September 2008 (has links)
O palmito pode ser obtido a partir de várias espécies de palmeiras. Devido à alta taxa de exploração das palmeiras do gênero Euterpe e ao seu baixo poder de regeneração, no mercado consumidor há falta de produto de boa qualidade. Palmeiras mais precoces e que produzam bom palmito têm sido pesquisadas, uma delas é a pupunha (Bactris gasipaes), nativa da Amazônia que apresenta características de precocidade, rusticidade e perfilhamento, com palmito de ótima qualidade, diferindo dos demais pelo sabor adocicado e a coloração amarelada. O seu cultivo pode ser feito em grande parte do território brasileiro. A porção comestível do palmito de pupunha é dividida em três partes: a basal ou caulinar (coração), a apical, e a central ou foliar (creme ou tolete). O comércio de palmito privilegia a parte central da palmeira, vendendo o palmito basal como subproduto. O presente estudo tem como objetivo demonstrar a equivalência da qualidade do palmito basal e do foliar de pupunha, priorizando-se o tratamento adicional com ácido acético, que mascara o seu sabor adocicado, comparado com o ácido cítrico, largamente utilizado nas indústrias. As amostras de palmito de pupunha foram cultivadas em área experimental pertencente a ESALQ/USP; para o processamento foram cortadas 120 palmeiras em março de 2007. Foram analisadas características físicas, químicas, bioquímicas e sensoriais do palmito basal e foliar de pupunha em seis períodos de armazenamento (1, 15, 30, 60, 90, 120 dias). O controle das operações durante o processamento foi eficiente, pois o peso e o preenchimento dos vidros não variaram entre as unidades. Durante o período de armazenamento a coloração amarelada dos palmitos basal e foliar de pupunha se manteve constante. Embora as enzimas polifenoloxidase e peroxidase tenham sido detectadas nas análises bioquímicas, seus valores foram baixos, e como a coloração foi a mesma durante o armazenamento, considera-se que as enzimas foram inativadas. A composição centesimal das amostras (umidade, proteína, matéria graxa, fração cinza, fibras e carboidratos) indicou que ambos os produtos possuem as mesmas características, as quais se assemelham muito à da palmeira juçara. A análise sensorial não mostrou diferença significativa entre as amostras, porém as notas mais baixas foram atribuídas às conservas acidificadas com ácido acético. Com relação à freqüência de consumo, observou-se que o palmito de pupunha é pouco utilizado na alimentação humana, sendo a resposta às vezes predominante. Os resultados mostraram que o palmito basal e o foliar de pupunha têm as mesmas características físicas, químicas e sensoriais, indicando que o primeiro também pode ser comercializado como palmito de primeira qualidade; o período de armazenamento não alterou as principais características dos produtos. / The palm can be obtained from several palms trees. Besides of high rate of exploration of Euterpe palms trees and his low regeneration power, there is a lack of product in the consumer market. More precocious palms trees and which produce good palm heart have been investigated, one of them is the peach palm (Bactris gasipaes), native of Amazon region that presents characteristics of precociousness, rusticity and tillering with palm heart with good quality, differing of others for the slightly sweet taste and the yellowed coloration. His cultivation can be done in great part of the Brazilian territory. The edible portion of the palm is divided in three parts: basic one or caulinar (heart), apical and central or foliaceous (cream or thole). The commerce of palm privileges the central part of the palm tree, selling heart as by-product. The aim of this study was to demonstrate the equivalence of the quality of heart and thole of peach palm, acidified with citric acid, widely used in the industries, and with acetic acid that masks the slightly sweet taste. The samples of peach palm were cultivated in experimental area of ESALQ/USP and for the processing 120 palms trees were cut in march of 2007. Heart and thole of the palm were analysed by physical, chemical, biochemical and sensorial characteristics for six periods of storage (1, 15, 30, 60, 90, 120 days). The control of the operations on the processing was efficient, since the weight and the filling out from the glasses did not vary between the unities. During the period of storage the coloration of the tholes and hearts of palm peach was yellowed, characteristic that remained constant. Even though the enzymes polyphenol oxidase and peroxidase have appeared in the biochemical analyses, its values were low, and the coloration was the same during the storage. The centesimal composition of the samples (humidity, protein, oily matter, ash, fibers and carbohydrates) indicated heart and thole of peach palm have the same characteristics, which liken very much to that of the palm tree Euterpe edulis. The sensory analysis did not show significant difference between the samples, however the lowest notes were attributed to the pickles acidified with acetic acid. Regarding the frequency of consumption, it was noticed that the palm heart of peach palm is little used in the feeding of people, being the answer \"sometimes\" the one that had major constancy. Data showed that heart and the thole of peach palm have the same physical, chemical and sensory characteristics, indicating that the first one also can be marketed like palm heart of first quality; the period of storage did not change principal characteristics of the products.
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Estabilidade oxidativa de óleo de soja adicionado de extratos de especiarias: correlação entre parâmetros físico-químicos e avaliação sensorial / Oxidative stability of soybean oil added of spices extracts: correlation between physicochemical parameters and sensory evaluation

Ravelli, Débora 11 October 2011 (has links)
Os antioxidantes são substâncias capazes de inibir a oxidação lipídica, responsável pela produção de compostos de cor, aroma e sabor indesejáveis. Na busca por produtos naturais associada à crescente preocupação com a saúde do consumidor, à vista dos possíveis riscos que o uso irregular dos antioxidantes sintéticos pode acarretar ao homem, torna-se essencial verificar a viabilidade do emprego de compostos naturais, com poder antioxidante, em um óleo cuja suscetibilidade à oxidação é reconhecidamente elevada. Com esse objetivo, o presente trabalho avaliou a proteção antioxidante oferecida por extratos hidroalcoólicos de especiarias ao óleo de soja. Os resultados físico-químicos do teor de compostos fenólicos totais, do sequestro do radical livre DPPH (1,1-difenil-2-picrilidrazil), Trolox, da estabilidade oxidativa, através de teste acelerado em estufa e em Rancimat, e da qualidade oxidativa, como o índice de peróxido e a absortividade na faixa do UV, foram base para a seleção dos extratos de alecrim, sálvia, tomilho e orégano, os quais apresentaram maior potencial antioxidante. Os extratos de alecrim, sálvia e tomilho, adicionados ao óleo de soja, foram igualmente eficientes em sua ação antioxidante no teste acelerado em estufa. O óleo, adicionado destes extratos, foi avaliado sensorialmente para verificar o mais preferido pelos consumidores quanto às características de cor, aroma e sabor. Houve uma preferência pelo óleo de soja adicionado de extrato de alecrim. / Antioxidants are compounds able of inhibiting lipid oxidation, responsible for the production of compounds of undesirable color, aroma and flavor. The search for natural products associated with the growing concern over the health of the consumer, in view of the possible risks that the irregular use of synthetic antioxidants can lead to man becomes essential to checking the feasibility of employing natural compounds with antioxidant power, in oil whose susceptibility to oxidation is high. With this purpose, the present study aimed to evaluate the antioxidant protection offered by hydroalcoholic extracts of spices to soybean oil. Analytical results of total phenol compounds, content of kidnapping free radical DPPH (1,1-diphenyl-2-picrilidrazil) substances, Trolox, oxidative stability, through accelerated test in Schaal oven and Rancimat tests, oxidative status, as the acid value and peroxide and absorptivity in the UV range, had been the basis for the selection of extracts of rosemary, sage, thyme and oregano, which presented the highest antioxidant potential. Rosemary, sage and thyme extracts added to soybean oil were similarly efficient as antioxidant in the Schaal Oven Test. Oil added of these extracts were sensorially evaluated according to their colour and flavor. Based on these sensorial characteristics, consumers preferred soybean oil added of rosemary extract.

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