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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.
31

Evaluation of strains of Bacillus thuringiensis as biological control agents of the adult stages of the carrot weevil, Listronotus oregonensis (Coleoptera:Curculionidae)

Saade, Fabienne Eugenie Joseph January 1993 (has links)
Strains of Bacillus thuringiensis active against Coleoptera were evaluated for toxicity against the adult stage of the carrot weevil, Listronotus oregonensis. Mortality and frass bioassays using a suitable semi-artificial diet showed strains A30, A429 and BTT to be highly toxic. Mortality persisted after initial exposure to the bacteria with the survivors not resuming normal feeding. Attempts to reisolate B. thuringiensis from the insects revealed B. thuringiensis-like organisms in the gut and in/on other structures. At the midgut pH of the insect (pH 8.0), the crystals of the toxic strains were significantly more soluble in vitro than were crystals of the less toxic strain A311. Proteolytic activation of the crystals with gut extracts yielded a protein band (66-67 kDa) for strains A30 and A429 which was similar to he apparent molecular weight of the toxin protein for BTT. Evidence suggests that the low toxicity of strain A311 might be due, in part, to the absence of the toxic moiety of the $ delta$-endotoxin.
32

Host selection behavior of the adult parasitoid Microctonus hyperodae Loan (Hymenoptera:Braconidae:Euphorinae) and the egg parasitoid Anaphes victus Huber (Hymenoptera:Mymaridae), parasitoids of the carrot weevil, Listronotus oregonensis LeConte (Coleoptera:Curculionidae)

Cournoyer, Michel, 1976- January 2003 (has links)
The carrot weevil, Listronotus oregonensis LeConte (Coleoptera: Curculionidae), is an important pest of carrot in northeastern North America. The objective of this study was to determine the host selection stimuli used by two L. oregonensis parasitoids: the adult parasitoid Microctonus hyperodae Loan and the egg parasitoid Anaphes victus Huber. / In the first chapter, the response of M. hyperodae females to various odor components from potential hosts and host plants was tested with a Y-olfactometer. / In the second chapter, the effect of L. oregonensis adult sex, feces and movement on host selection behavior of M. hyperodae females was evaluated by quantifying L. oregonensis adult movement and various M. hyperodae female behaviors in an arena. / In the third chapter, the response of A. victus females to different L. oregonensis related odor components was evaluated using a filter paper of which half was moistened with odor components and the other half with water.
33

Mathematical models for the population dynamics and management of the carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera:Curculionidae)

Zhao, Dingxin January 1990 (has links)
The time-varying survival rates of the carrot weevil, Listronotus oregonensis, were estimated by a new method. This method precluded the possibility of negative simulation survival rates. Analysis of carrot weevil population dynamics indicated that the egg mortality was density dependent with Anaphes sordidatus, an egg parasitoid, as a major density dependent factor. Larval mortality was less density dependent. Based on the mortality information, a simulation model for carrot weevil population dynamics was established. The simulation precision, evaluated by comparing simulated and observed egg and larval population dynamics, was satisfactory. Sensitivity analysis indicated that A. sordidatus had a large influence on carrot weevil population dynamics. The economic threshold for carrot weevil control in early carrots was 5 eggs/100 carrots at the peak population density. It ranged from 3.8 to 5.3 eggs/100 carrots in mid-season carrots depending on the selling price. A decision model showed that the best sowing date was after June 5 when risks were not considered. For risk aversion growers, sowing carrots between May 20 and May 31 was the best choice.
34

Effects Of Different Batter Formulations On Quality Of Deep-fat Fried Carrot Slices

Akdeniz, Neslihan 01 August 2004 (has links) (PDF)
The main objective of the study was to evaluate the effects of starch and gum types on product quality of deep-fat fried carrot slices. It was also aimed to evaluate the applicability of image processing for determination of oil uptake. In the first part of the study, carrot slices were dipped into batters containing three different concentrations of dextrin or pre-gelatinized tapioca starch and fried for 2, 3, and 4 minutes at 170&plusmn / 2 oC. Coating pick-up of batter formulations and moisture content, oil content, frying yield, bulk density, porosity, texture and color of fried slices were evaluated. In the second part of the study, the effects of different gum types (HPMC, xanthan gum, guar gum, guar-xanthan gum combination) on quality attributes were studied. No starch or gum added coating formulation was used as the control. Finally, images of carrot and batter sections of the fried samples were obtained using digital camera and area fractions of oil droplets were determined using image processing. Acceptable product quality was obtained at higher concentrations of pre-gelatinized tapioca starch. On the other hand, increasing dextrin concentrations had an adverse affect on the product quality. As a result of the study, guar-xanthan gum combination has been found as the most effective additive on the batter performance. This additive provided the highest moisture content, lowest oil content, highest volume and lightest color to the product after frying. The porous and crunchy structure obtained using this combination was at the acceptable level for deep-fat fried products. Determination of area fraction of oil droplets on carrot and batter surfaces of fried samples using image processing was correlated with the oil content of fried product at initial stages of frying. The correlation coefficient between moisture content and frying yield was found as 0.90. A correlation was also determined between oil content and moisture content (r= -0.88).
35

Mathematical Analysis Of Peeling Of Carrots

Aydin, Ozlem 01 August 2005 (has links) (PDF)
In this study, carrots of Beypazari variety, cultivated during 2004 season were chemically and steam peeled. Effects of temperature, concentration of NaOH solutions and immersion time on lye peeling of carrots were studied / optimum time-temperature-concentration relations were analyzed mathematically. Then suitable combinations of concentration, temperature and time were determined just by considering degree of peeling. Increases in both temperature and concentration of lye solution led to a decrease in peeling time. However it was observed that the temperature of the lye solution was the main effect on the quality of carrots. Treatment with 0.75 % NaOH at 77&deg / C for 10.5 minutes was found to be optimum to peel the carrots, mathematically. In steam peeling, the peeled surface area-time relations were analyzed mathematically. Complete peeling was achieved at 8.5 minutes. Under complete peeling conditions, the effect of chemical and steam peeling on quality of carrots were determined. Then the mathematical optimum value for chemical peeling was evaluated for quality parameters. The optimum chemical peeling value was fitted to the peeling yield-pectin relations. The peeling yield of steam peeled carrot was higher than the chemically peeled carrot. The color of the chemically peeled carrot had the highest consumer acceptance compared to conventional peeling. Finally, the two conditions were suitable for considering the need of the plant design.
36

Desenvolvimento de raízes de cenoura (Daucus carota l. var. Esplanada) em solo submetido a diferentes compostos orgânicos. / Development of carrot rots (Daucus carota L. var. Esplanada) in a soil submitted to different organic compounds.

Martins, Gustavo de Oliveira 30 June 2008 (has links)
The mini-carrot commerce is increasing, in Brazil, alongside of the years. An exigent market presuppose high-quality products and in sufficient amount to attend it. So, organic fertilization shows itself like a very important instrument to obtain more healthy products and to maintenance a no expensive sustainable production. Thus, this work searched evaluate the development of carrot Esplanada roots, cultivated using different organic compounds. The treatments consisted in the application of 12 compounds, bovine manure and mineral fertilizer, on a Podzol hydromorphic eutrophic from Arapiraca-AL, being the plants of carrot cultivated in a greenhouse resulting in 14 treatments. These treatments were put in a completely randomized blocks design using four replications. Were evaluated: length, diameter, roots production and nitrogen, phosphorus, potassium, calcium and magnesium content. The organic compounds were made up from two basic mixes: MBsugarcane (mix with sugarcane bagasse + sugar plant filter cake + bovine manure + natural phosphate) and MBcoconut (mix where the sugarcane bagasse was changed by coconut bagasse) using increasing stillage doses, obtaining different compounds: C1: MBsugarcane; C2: MBsugarcane + 25% stillage solution; C3: MBsugarcane + 50% stillage solution; C4: MBsugarcane + 75% stillage solution; C5: MBsugarcane + 100 % stillage; C6: MBsugarcane + water + potassium sulfate; C7: MBcoconut; C8: MBcoconut + 25% stillage solution; C9: MBcoconut + 50% stillage solution; C10: MBcoconut + 75% stillage solution; C11: MBcoconut + 100 % stillage and C12: MBcoconut + water + potassium sulfate. The data had been submitted to the analysis of variance and the averages compared between itself for the Tukey test, with P < 0,05, besides of the orthogonal contrast for phosphorus content of the roots. Statistical differences were not found between the treatments to the length, diameter and roots production variables. In relation to the nutrients absorption, there were not statistical difference, except to the phosphorus absorption, with the compounds made up of sugarcane bagasse, showing a better result than the others treatments. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O mercado de minicenouras vem crescendo, no Brasil, a cada ano que passa. Um mercado exigente pressupõe produtos de boa qualidade e em quantidade suficiente para atendê-lo. A adubação orgânica, nesse sentido, tem se mostrado uma ferramenta muito importante para a obtenção de produtos mais saudáveis e para a manutenção de uma produção sustentável e sem gastos excessivos. Assim, o presente trabalho teve por objetivo avaliar o desenvolvimento de raízes de cenoura da variedade Esplanada, cultivadas com diferentes compostos orgânicos. Os tratamentos consistiram da aplicação de 12 compostos, esterco bovino e fertilizante mineral em um Espodossolo Ferrocárbico Órtico êutrico, proveniente de Arapiraca-AL, em condições de cada de vegetação, totalizando 14 tratamentos, no qual cultivou-se cenoura, variedade Esplanada. Estes tratamentos foram dispostos em delineamento de blocos casualizados com 4 repetições. Avaliaram-se as variáveis: comprimento, diâmetro, produção de raízes e absorção de nitrogênio, fósforo, potássio, cálcio e magnésio. Estes compostos orgânicos foram mesclados a partir de duas misturas básicas: (MBcana, mistura contendo bagaço de cana + torta de filtro + esterco bovino + fosfato natural e MBcoco, mistura onde o bagaço de cana foi substituído por bagaço de coco-verde), nos quais adicionouse soluções com concentrações crescentes de vinhaça, obtendo-se 12 compostos distintos: C1: MBcana; C2: MBcana + solução com vinhaça a 25%; C3: MBcana + solução com vinhaça a 50%; C4: MBcana + solução com vinhaça a 75%; C5: MBcana + 100 %vinhaça; C6: MBcana + água + sultafo de potássio; C7: MBcoco; C8: MBcoco + solução com vinhaça a 25%; C9: MBcoco + solução com vinhaça a 50%; C10: MBcoco + solução com vinhaça a 75%; C11: MBcoco + 100 % vinhaça e C12: MBcoco + água + sulfato de potássio. Os dados foram submetidos à análise de variância e as médias comparadas entre si pelo teste Tukey, com P < 0,05, além de terem sido feitos contrastes ortogonais para o teor de fósforo das mesmas, mediante o software Sisvar. Não foram verificadas diferenças estatísticas entre os tratamentos para as variáveis comprimento, diâmetro e produção de raízes. Em relação à absorção de nutrientes, também não houve diferença estatística entre os tratamentos, com exceção à absorção de fósforo, onde pôde se observar um melhor desempenho dos tratamentos à base de bagaço de cana.
37

Resposta da cultura da cenoura à irrigação conduzida com diferentes métodos de manejo / Response of carrot crop irrigation to conducted with different methods of management

Rosa, David Rafael Quintão 12 July 2012 (has links)
Made available in DSpace on 2015-03-26T13:23:45Z (GMT). No. of bitstreams: 1 texto completo.pdf: 2284395 bytes, checksum: cb6baf1b77c16818f655c94df6f6e9da (MD5) Previous issue date: 2012-07-12 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / Among all the vegetables cultivated in Brazil, carrot (Daucus carota L.) is one of the most commonly cultivated. Due to its sensitivity to water stress conditions, continuous irrigation is necessary to supply the water needs of the crop in order to guarantee a good yield. To assure an efficient use of water in agriculture, an irrigation method to maximize the productivity of the crop with the water applied is needed. This way, the objectives of this work were to compare depths of water applied with irrigation and the yield of the carrots obtained with the use of different methods of irrigation management. In order to achieve the proposed objectives, an experiment with four different irrigation treatments and 5 repetitions, based on a completely randomized block design was used. It was installed in the Experimentation Area of Irrigation and Drainage of the Department of Agriculture Engineering of the Federal University of Vicosa (UFV). The depths of water applied in each treatment were obtained with the use of different irrigation management methods. These were: Penman-Monteith FAO 56, Class A pan, Irrigâmetro , and the TDR method. Fertilization was performed as recommended for the crop in the state of Minas Gerais. The planting of the carrots happened on the 4th of March, 2012, and the irrigation for the methods Penman-Monteith FAO 56 and the Class A pan was made based on the schedule of irrigation of once per day until 50 days after the beginning of the experiment. After that, the schedule irrigation increased to once every two days until the end of the study. For the Irrigâmetro and TDR methods, the schedule irrigation varied according to the characteristics of each of them. After 90 days, the carrots were harvested; the roots were washed, dried, and classified in 5 different classes. The classes were G, Extra AA, Extra A, Extra and Discard, according to their length. The statistical analysis consisted of analysis of variance, and tests of Dunnett and Tukey in order to compare the averages. The irrigation depth was of 111.39 mm calculated with the Penman-Monteith FAO 56 method; 103.3 mm with the Class A pan; 93.5 mm with the Irrigâmetro method; and 83.65 with the TDR method. The total average yields were: 62.62, 66.92, 62.92, 62.56 t ha-1 with the calculated amount of water by the methods Penman-Monteith FAO 56, Class A pan, Irrigâmetro , and TDR, respectively. The results lead to the conclusion that there was not a considerable difference between the irrigation depths with the different irrigation management treatments. Also, there were no significant differences between the yields, dry organic matter of the leaves and of the roots, and the length of the top between the used methods. / A cenoura (Daucus carota L.) é uma das principais olerícolas cultivadas no Brasil. Devido a sua sensibilidade ao déficit hídrico, a aplicação de lâminas de irrigação suficientes para suprir a demanda hídrica da cultura, torna-se um dos fatores mais importantes para a obtenção de altas produtividades. Para o uso racional da água na agricultura irrigada é necessária a adoção de um método de manejo da irrigação que seja capaz de maximizar a produtividade por lâmina aplicada. Desta forma, objetivou-se comparar as lâminas de irrigação e as produtividades de cenoura com a aplicação de lâminas de irrigação, calculadas com a utilização de quatro métodos de manejo da irrigação. Para alcançar os objetivos propostos, instalou-se na Área Experimental de Irrigação e Drenagem, do Departamento de Engenharia Agrícola da Universidade Federal de Viçosa, localizada em Viçosa, MG, um experimento em um delineamento em blocos casualizados, com quatro tratamentos e cinco repetições. Os tratamentos constituíram das lâminas de irrigação obtidas utilizando quatro métodos de manejo da irrigação: Penman-Monteith FAO 56, Tanque Classe A, Irrigâmetro e o método da TDR. A adubação foi realizada conforme recomendações para a cultura no estado de Minas Gerais. A semeadura da cenoura foi realizada em 04 de março de 2012. As irrigações para os métodos de Penman-Monteith FAO 56 e do Tanque Classe A foram realizadas com turno de rega diário até 50 dias após o plantio; logo depois aumentou-se o turno de rega para dois dias até o final do ciclo da cultura. Os coeficientes de culturas (kc) utilizados foram iguais a 0,75; 0,85; 0,95 e 0,90 para os estádios de desenvolvimento I, II, III e IV respectivamente. Para os métodos do Irrigâmetro e o método da TDR, os turnos de rega variaram de acordo com as características de cada um destes métodos. Após o ciclo de 90 dias, as cenouras foram colhidas, as raízes lavadas, secas e classificadas, determinando-se as massas correspondentes a cinco classes. As classes de classificação foram denominadas de G, Extras AA, Extra A, Extra e Descartes, de acordo com o comprimento. A análise estatística consistiu de análise de variância e testes de Dunnett e de Tukey, para comparação das médias. Foram aplicados 111,39 mm calculados por meio do método de Penman-Monteith FAO 56, 103,3 mm com o método do Tanque Classe A, 93,5 mm com o método do Irrigâmetro e 83,65 mm com o método da TDR. As produtividades médias totais obtidas foram de 62,62; 66,29; 62,92 e 62,56 t ha-1 com as lâminas calculadas com os métodos de Penman-Monteith FAO 56, Tanque Classe A, Irrigâmetro e o método da TDR, respectivamente. Os resultados permitiram concluir que não houve diferença significativa entre as lâminas médias aplicadas considerando os métodos de manejo da irrigação. Também não houve diferença significativa entre as produtividades, teores de matéria seca da parte aérea e das raízes e comprimento da parte aérea, entre os métodos utilizados.
38

Condicionamento osmótico de sementes de cenoura (Daucus carota L.) / Osmotic priming of carrot (Daucus carota L.) seeds

Pereira, Márcio Dias 12 March 2007 (has links)
Made available in DSpace on 2015-03-26T13:40:06Z (GMT). No. of bitstreams: 1 texto completo.pdf: 841838 bytes, checksum: 2f74673c08ddf09fecd2254f44e904dc (MD5) Previous issue date: 2007-03-12 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / This work had as objectives: i) to monitor carrot seeds hydration in water and osmotic solutions, in way to define appropriate conditions for priming of those seeds; ii) to evaluate the effects of priming on germination, vigour and performance of carrot seeds under water and temperature stress conditions. Two steps were conducted at Seed Research Laboratory in the University Federal of Viçosa using two seed lots of carrot, Brasília cultivar. In the first step, the seeds were imbibed in osmotic solutions of PEG 6000 at -1.0 and -1.2 MPa and in distilled water, in an incubator BOD at 20º C, using two different hydration methods: imbibition in paper towel moistened and in aerated solutions, provided by an air pump accomplished in the erlenmeyers containing the respective solutions. The imbibition curves for each seed lot were drawn after to determine the seed moisture content at 2, 4, 6, 8, 10, 12, 24, 48, 72, 96 hours hydration in water and after 2, 4, 6, 8, 10, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216, 264, 312 hours hydration in the PEG 6000 solutions. The data were submitted to the variance and regression analysis. In the second step, seeds of each lot were primed in PEG 6000 -1.0 and -1.2 MPa solutions for 4 and 8 days, at 20o C, using the both hydration methods described above (paper towel moistened and aerated osmotic solutions). Non-primed seeds were used as control. After priming, the seeds were dried at room temperature until reach initial seed moistened content. The seeds were submitted to the following tests: germination, first count, percentage and speed of seedling emergence in the field, seedling and primary root length, germination under sub-optimal and supra-optimal temperatures, germination under water stress and controlled deterioration. Trials were conducted in randomized completely design, with four replications, and analyzed as factorial experiment (2 lots x 2 priming methods x 5 priming treatments). The results allowed to conclude that seed hydration in the distilled water was faster than in PEG 6000 solutions, beginning the protrusion of the primary root at 48 hours imbibition, when they reached 54% of moisture content. Seeds imbibed in PEG 6000 -1.0 and -1.2 MPa solutions did not emit the primary root until 312 hours of imbibition, when the seed moisture content was 50%. The aeration of solutions allowed the fastest seed hydration when compared to the hydration in paper towel moistened. Seed priming was effective in increasing the percentage and speed of germination and seedling emergence in field. Increases in the percentage and germination speed were obtained by priming in PEG 6000 -1.0 MPa for 4 days, while larger seedling growth was observed in the PEG 6000 -1.2 MPa solution, for 8 days, with aeration. Seed performance under water and temperature stress conditions was improved by priming in PEG 6000 at -1.0 and -1.2 MPa, for four days. / O presente trabalho teve como objetivos: i) monitorar a hidratação de sementes de cenoura em água e em soluções osmóticas, de modo a definir condições adequadas para o condicionamento osmótico dessas sementes; ii) avaliar o efeito do condicionamento osmótico na germinação, vigor e desempenho das sementes sob condições de estresse. Para tanto, foram conduzidos dois experimentos no Laboratório de Pesquisa de Sementes do Departamento de Fitotecnia da Universidade Federal de Viçosa (UFV), utilizando-se dois lotes de sementes de cenoura, cultivar Brasília. No ensaio 1, monitorou-se a hidratação das sementes de cenoura em água destilada e em soluções osmóticas de PEG 6000 a -1,0 e -1,2 MPa, em incubadora BOD a 20ºC, utilizando-se dois métodos de embebição para o condicionamento: embebição em papel toalha umedecido e em soluções aeradas, realizada em frascos contendo as respectivas soluções, acoplados a uma bomba de ar. Para a obtenção das curvas de embebição, determinou-se o teor de água das sementes após 2, 4, 6, 8, 10, 12, 24, 48, 72, 96 horas de embebição em água e após 2, 4, 6, 8, 10, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216, 264, 312 horas de embebição nas soluções de PEG 6000. Os dados foram submetidos à análise de variância e de regressão. No segundo ensaio, as sementes de cada lote foram condicionadas em soluções de PEG 6000 a -1,0 e -1,2 MPa por 4 e 8 dias, a 20ºC, utilizando-se dois métodos de embebição: em papel toalha umedecido com as respectivas soluções e imersão em soluções osmóticas aeradas. Utilizaram-se sementes não condicionadas como testemunha. Após o condicionamento, realizou-se a secagem das sementes em ambiente de laboratório até atingirem o grau de umidade inicial. Em seguida, avaliou-se o desempenho das sementes pelos seguintes testes: germinação, primeira contagem de germinação, porcentagem e velocidade de emergência das plântulas em campo, comprimento de plântula, comprimento de radícula, germinação em temperatura sub-ótima e supra-ótima e germinação sob estresse hídrico. O experimento foi conduzido em delineamento inteiramente casualizado, com quatro repetições, e analisado em esquema fatorial (2 lotes x 2 métodos de condicionamento x 5 tratamentos de condicionamento). As sementes embebidas em soluções de PEG 6000 a -1,0 e -1,2 MPa não emitiram raiz primária mesmo após 312 h de embebição, quando o teor de água era de 54% e o uso de soluções aeradas permitiu a hidratação mais rápida das sementes quando comparada à hidratação em papel toalha. Também verificou-se que o condicionamento osmótico aumentou a porcentagem e velocidade de germinação e emergência das plântulas em campo. Aumentos na porcentagem e velocidade de germinação foram obtidos com o condicionamento das sementes em solução de PEG 6000 a -1,0 MPa por 4 dias, enquanto maior crescimento de plântula foi observado a -1,2 MPa por 8 dias em solução aerada. Já o condicionamento osmótico em PEG 6000 a -1,0 e -1,2 MPa, por 4 dias, melhorou o desempenho das sementes sob condições de estresse hídrico e térmico, tanto em temperatura sub como supra-ótima.
39

Desenvolvimento de bolo de cenoura sem glúten com sacarose e diet e estudo do impacto do edulcorante no perfil sensorial e na aceitação do consumidor / Development of gluten-free carrot cake with sucrose and diet and study on the impact of sweeteners and sensory profile consumer

Maurício, Angélica Aparecida, 1972- 07 July 2011 (has links)
Orientador: Helena Maria André Bolini / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-08-19T01:17:22Z (GMT). No. of bitstreams: 1 Mauricio_AngelicaAparecida_D.pdf: 2435386 bytes, checksum: 5945d9533cc0ccfd4509978a82ba8f53 (MD5) Previous issue date: 2011 / Resumo: As mudanças no processamento e a crescente exigência do consumidor por alimentos que apresentem, além da alta qualidade sensorial e nutricional, benefícios associados à saúde, fazem surgir à necessidade de novos produtos que possam atender a essas exigências do mercado. O presente trabalho teve como principal objetivo o desenvolvimento e a caracterização de um bolo de cenoura sem glúten e diet, avaliar a aceitação por consumidores e determinar a intenção de compra. Para dar início a pesquisa, primeiramente, desenvolveu-se um mix de farinhas sem glúten a fim de identificar as características do bolo produzido com o mix e compará-las aos 2 tipos de bolo produzidos com glúten, mas com diferentes tipos de gordura. As formulações de bolo isentos de glúten (BIG) produzidos com MIX -1 e MIX +1, bolo com glúten e óleo de milho (BGOM) e bolo com glúten e óleo de palma (BGOP) 80 e 100g, foram avaliadas quanto ao seu valor nutricional, preferência e intenção de compra. Os bolos BIG MIX-1 e BGOP 80g apresentaram valor nutricional, preferência e intenção de compra comparáveis ao da formulação padrão. Portanto, o MIX-1 isento de glúten e o óleo de palma podem ser utilizados como ingredientes de bolo de cenoura, fornecendo produtos com características que atendem às exigências do mercado consumidor. Para dar continuidade à pesquisa, o novo objetivo traçado foi a partir do mix isento de glúten, que buscou desenvolver e padronizar novas fórmulas de bolo de cenoura sem glúten e avaliar sua aceitação. Para tal, devido ao grande número de variáveis, optou-se por utilizar somente o mix de farinhas isenta de glúten e o óleo de milho, deixando assim a sugestão de novos experimentos com óleo de palma. Para o delineamento experimental com 12 ensaios, foram elaborados três diferentes mix de quatro farinhas sem glúten. Os atributos dos bolos preparados com esses mix foram comparados com os atributos do bolo padrão com glúten. Os resultados foram analisados por ANOVA, Teste de Tukey (p<0,05) e Análise de Cluster. Houve três ensaios que não diferiram significativamente do bolo padrão. As melhores formulações obtiveram razão de massa entre seis e quatro. As fórmulas sem glúten obtiveram notas de aceitação global entre 7,55 e 6,80 e a padrão, 7,15. Os atributos dureza, fraturabilidade, adesividade e gomosidade interferiram negativamente na aceitação e, maciez, elasticidade, coesividade e atividade de água interferiram positivamente. Dessa forma, é possível afirmar que é viável substituir a farinha de trigo por farinhas isentas de glúten na produção de bolo de cenoura mantendo suas características sensoriais. Depois de ter chegado a resultados que apontaram que a razão da massa entre seis e quatro foram as que sugeriram melhor resposta sensorial e instrumental, optou-se por dar continuidade à pesquisa padronizando as formulações isentas de glúten em relação à formulação padrão com glúten e também se inseriu um novo mix de farinhas isento de glúten e sem fubá uma vez que alguns consumidores comentaram detectar sabor de fubá nos bolos sem glúten. Além disso, elaborouse a versão diet (sem sacarose) das fórmulas sem glúten. Sendo assim, deu-se continuidade a pesquisa com o objetivo de avaliar o perfil sensorial e temporal e o índice de aceitação global das sete diferentes fórmulas de bolos de cenoura, com e sem glúten diet ou com sacarose. As fórmulas foram então submetidas aos testes descritivos de Análise Descritiva Quantitativa (ADQ) com 12 provadores treinados, e Análise de Tempo-Intensidade (TI) com 13 provadores treinados. Os resultados foram analisados por ANOVA, teste de Tukey (p<0,05) e Análise de componentes Principais (ACP). Para complementar as análises, aplicou-se teste de Aceitação Global (120 consumidores) analisado por ANOVA, Tukey (p<0,05) e Mapa de Preferência Externo (MPREFE) que permitiu conhecer os atributos descritivos preferidos pelo público consumidor a fim de garantir a aceitação do produto. Foram definidos 16 termos descritores para o estudo de ADQ e, somente o atributo gosto doce passou por estudo temporal. Observou-se que as amostras que continham fubá em sua fórmula apresentaram-se mais quebradiças, arenosas, aparentemente mais secas, menos macias e menos elásticas quando comparadas as fórmulas sem fubá. Em contrapartida, as fórmulas sem fubá mostraram-se mais adesivas, porém, com melhor sabor e aroma de cenoura, enquanto que a amostra padrão, com glúten e sacarose, caracterizou-se por ser a mais macia, devido à presença de glúten. Quanto ao estudo temporal de gosto doce, as amostras não apresentaram diferença significativa entre si. As diferenças observadas pela equipe treinada de ADQ não foram detectadas pelos consumidores, que demonstraram boa aceitação para todas as amostras sem diferença. Além disso, pelo MPREFE, foi possível concluir que os consumidores esperam que bolo de cenoura seja mais macio e úmido, além de poroso e com aroma adocicado, mesmo esses dois últimos atributos sendo esperados em menor intensidade. Concluiu-se, portanto, que a substituição de farinha de trigo e sacarose em bolo de cenoura é possível e atende as expectativas dos consumidores. Para finalizar a pesquisa, fez-se novamente a análise de aceitação das sete fórmulas de bolo de cenoura, padrão e sem glúten, com e sem sacarose, com objetivo de avaliar os atributos aparência, aroma, sabor, textura e impressão global com 120 consumidores de bolo de cenoura por utilização de escala hedônica linear de 9 cm. Os dados foram analisados por ANOVA, teste de medias de Tukey (p<0,05), Mapa de Preferência Interno e Dendograma. Alem disso, dados de parâmetros de textura como dureza, adesividade, gomosidade, mastigabilidade, coesividade, fraturabilidade, maciez e elasticidade, atividade de água e cor das amostras foram analisados por Partial Least Square (PLS) para que fosse possível determinar a influência desses parâmetros instrumentais na aceitação hedônica dos consumidores. Observou-se que todos os bolos foram bem aceitos, exceto a amostra Sem Glúten Diet elaborada com mix +1 (SGD+1) uma vez que esta amostra deixou o consumidor em dúvida e foi a que obteve menores porcentagens para o aspecto avaliado de doçura ideal e intenção de compra e a que se apresentou com sabor mais acentuado de fubá. Quanto aos aspectos instrumentais analisados, coesividade e elasticidade influenciaram positivamente na aceitação dos produtos. Os demais parâmetros não foram considerados parâmetros relevantes pelos consumidores nas análises de aceitação dos bolos. Finalmente, obteve-se resultados de intenção de compra para as amostras por meio de escala de atitude estruturada de 5 pontos. Os provadores indicaram ter interesse em adquirir os bolos, com exceção da amostra SGD+1, caso estivessem disponíveis para compra / Abstract: Changes in food process and the higher demand for foods that have health benefits, besides high sensory and nutritional quality, make new-products development necessary. This study aimed to develop different formulas of glutenfree carrot cake with maize oil and traditional carrot cakes with wheat flour and maize oil or palm oil. Acceptance by consumers, their purchase intention and the nutritional facts of the formulas were also goals of this research. Firstly, a mix of gluten-free flours was suggested in order to replace wheat flour in cakes. Glutenfree cake was compared to two types of cake made with wheat flour (gluten) and with different types of fat. The gluten-free cake (BIG) produced with MIX -1, the cake with gluten and maize oil (BGOM) and the cake with gluten and palm oil (BGOP) with 80 and 100g were assessed for their nutritional values, preference and purchase intent. BIG MIX-1 and BGOP 80g had nutritional values, preference and purchase intent comparable to standard formulation. Therefore, the glutenfree-flour mix (MIX-1) and palm oil can be used as ingredients for carrot cake, providing products with features that meet the requirements of the consumer market. Secondly, a new goal was drawn and new gluten-free formulas were developed and standardized from the first suggested gluten-free-flour mix. Acceptance rates were one more time evaluated. For this purpose and due to the large number of variables, mix of gluten-free flours and maize oil were the only two variables chosen. Thus, we left the suggestion of new experiments with palm oil. For the 12-essays-experimental design, three gluten-free mixes with four different gluten-free flours were developed. The attributes of the cakes made with these mixes were compared with the attributes of the standard cake, with gluten. The results were analyzed by ANOVA, Tukey test (p<0.05) and Cluster Analysis. Three trials did not differ significantly from standard cake. The best formulas have obtained mass ratio between six and four. Overall linking of the gluten-free formulas was scored between 7.55 and 6.80 and the standard, gained 7.15. Hardness, fracturability, gumminess and Adhesiveness interfered negatively in the acceptance, while Softness, resilience, cohesiveness and water activity interfered in a positive way. Thus, it can be said that it is feasible to substitute wheat flour for gluten-free flours in the production of carrot cake and keep its sensory characteristics. Once we have reached results that showed that the ratio of mass between six and four presented the best sensory and instrumental responses we decided to continue the research by standardizing the gluten-free formulations and also suggested a new mix of gluten-free flour, but at this time, without corn meal once some consumers commented that cakes with that flour tasted like cornmeal cake. In addition, we elaborated the diet version (without sucrose) of gluten-free formulas. So, the novel goal was to assess the sensory and temporal profiles and the overall acceptance rate of the new seven different formulas of carrot cakes. The formulas were then evaluated by Descriptive Quantitative Analysis (QDA) with 12 trained panelists and by Time-Intensity Analysis (TI) with 13 trained panelists. The results were analyzed by ANOVA, Tukey test (p<0.05) and Principal Component Analysis (PCA). In order to complement the analysis, Global Acceptance was carried out with 120 consumers and its results were analyzed by ANOVA, Tukey (p <0.05) and External Preference Mapping (MPREFE) which informed the descriptive attributes most preferred by the consumers in order to ensure acceptance of the products. Sixteen descriptor terms were defined during QDA study, and only sweet taste attribute underwent temporal study. It was observed that the samples that contained corn meal in its formula were more brittle, sandy, apparently drier, less elastic and less soft. In contrast, the formulas without cornmeal were more adhesive, but with better taste and flavor of carrots, while the standard sample, with gluten and sucrose, was said as being the softest, due to the presence of gluten. Cake samples showed no significant difference for the temporal profile of their sweet taste. The differences observed by the QDA trained panelists were not detected by consumers, who showed good acceptance for all samples with no difference. Furthermore, MPREFE shows that, for consumers, carrot cakes are supposed to be moist and soft, porous and smell sweet. Therefore, it was concluded that the replacement of wheat flour and sucrose in carrot cake is possible and meets consumer expectations. Finally, acceptance of appearance, aroma, flavor, texture and overall liking of the seven samples was evaluated by 120 consumers of carrot cake using the 9cm-linear scale. Data were analyzed by ANOVA, Tukey test (p <0.05), internal preference mapping and dendogram. Furthermore, data of texture parameters such as hardness, adhesiveness, gumminess, chewiness, cohesiveness, fracturability and resilience, water activity and color of the samples were analyzed by Partial Least Square (PLS) in order to determine the influence of instrumental parameters on consumers' hedonic acceptance. It was observed that all the cakes were well accepted, except the SGD 1, which sweetness seemed to be questionable. As for the instrumental aspects, cohesiveness and elasticity have influenced the acceptance of products. The other parameters were not relevant to the panelists. Finally, we obtained results for purchase intention using the 5-point-attitude scale. Panelists indicated an interest in buying the cakes, except for the SGD 1 sample / Doutorado / Consumo e Qualidade de Alimentos / Doutor em Alimentos e Nutrição
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Étude expérimentale et modélisation du procédé de séchage des végétaux / Experimental Study and Modeling of Vegetable and Fruit Drying

Nguyen, Thu Ha 12 June 2015 (has links)
Dans le séchage des fruits et légumes, beaucoup de questions non résolues subsistent. Le «Swell-drying» est un procédé de séchage couplant une étape de déshydratation par air chaud à la texturation par Détente Instantanée Contrôlée (DIC). Dans le cadre de ce travail de recherche, la carotte et la pomme sont utilisées comme aliment modèle pour le traitement de la plupart des végétaux. La littérature scientifique sur le séchage des agromatériaux est unanime sur l’effet positif de la température de l'air, l’effet négatif de l'humidité relative de l'air et de l'épaisseur vis-à-vis du temps de séchage. Cependant, malgré un nombre important d’études, des conclusions contradictoires sont notées en termes de corrélations entre la cinétique de séchage et la vitesse de l'air qui, selon certains auteurs, n’entraîne aucune modification du séchage; alors que certains travaux ont tenté d'établir des modèles empiriques entre la diffusivité effective et la vitesse de l'air ; ce qui est fondamentalement erroné. L’objectif de cette thèse est d’analyser les phénomènes de transfert pendant le processus du séchage et d'identifier le phénomène limitant entre les transferts internes et externes. Ce travail aboutir à l’identification de la vitesse critique de l'air CAV capable de rendre la diffusion interne de l’eau comme phénomène limitant. La CAV doit donc dépendre de la diffusivité effective et de la taille du produit. À partir de résultats expérimentaux qui couvrent de larges plages de température d’air, de teneur en eau, et de taux d'expansion absolu, un modèle empirique a été établi. / Great research works support the sector of drying of fruits and vegetables in a number of ways. Each year, experimental results and mathematical modelling try through conventional and innovative technological processes to protect agricultural products from seasonality and variability in the market prices. Nonetheless, there still exist considerable issues to improve and control this strategic agricultural sector. Swell-drying is very relevant drying process coupling hot air dehydration with Instant Controlled Pressure Drop (DIC). In the present work, carrot and apple were used as a fruit and vegetable model. Scientific literature on drying is unanimous that the drying time decreases with increasing air temperature, decreasing air relative humidity, and reducing thickness. However, the effect of airflow velocity leads to contradictory conclusions. Some authors have claimed that it does not trigger any modification of drying; while some articles tried to establish empirical models of the effective diffusivity versus airflow velocity; what is fundamentally erroneous. This thesis aims at analyzing external and internal transfer phenomena during drying. So, it was possible to recognize the Critical Airflow Velocity CAV depending on the effective diffusivity and the product size, to have the internal water transfer as the limiting phenomenon. From experimental results, an empirical model was established between the effective moisture diffusivity and airflow temperature, water content, and absolute expansion ratio.

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