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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.
1

The significance of genetic variability to the physicochemical behaviour of starch granules

Goward, Y. M. January 1987 (has links)
No description available.
2

Efeito da moagem em moinho de bolas e do tratamento térmico com baixa umidade sobre as características estruturais e físico-químicas dos amidos de mandioca e mandioquinha-salsa

Moraes, Jaqueline de [UNESP] 27 February 2012 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-27Bitstream added on 2014-06-13T18:09:35Z : No. of bitstreams: 1 moraes_j_me_sjrp.pdf: 2112448 bytes, checksum: ed452df585200024abb876d84e443859 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Amidos com regiões cristalinas menos extensas podem ser usados em diversas aplicações industriais, pois apresentam maior solubilidade a frio, menor temperatura de gelatinização e maior reatividade. O tratamento térmico a baixa umidade (TTBU) e a moagem em moinho de bolas são métodos de modificação física que podem resultar em alterações na região cristalina dos amidos. O objetivo deste projeto foi investigar as alterações físico-químicas e estruturais provocadas pelos dois tratamentos em amidos de mandioquinha-salsa e mandioca. O TTBU foi realizado com amidos condicionados a 30 e 35 % de umidade a 90º C por 8 horas. A moagem em moinho de bolas dos amidos foi realizada durante 2, 4, 8, 16 e 32 horas. As propriedades físico-químicas e estruturais dos amidos foram determinadas. A moagem em moinho de bolas provocou alterações nas propriedades dos amidos, principalmente após 8 h de tratamento. Os resultados obtidos por HPAEC-PAD, GPC e teor de amilose indicaram o rompimento das pontes de hidrogênio e ligações glicosídicas α (1→6) das moléculas de amido. A partir dos difractogramas de raios-X foi observado que a área cristalina dos grânulos de amido reduziu com a moagem, o que foi confirmado pela redução da cristalinidade nos amidos moídos. Grânulos de ambos os amidos moídos a partir de 2 h apresentaram fissuras que foram observadas por MEV e fragmentos de grânulos foram gerados nos maiores tempos de moagem resultando no aumento do ISA e redução do IAA. Os perfis de RVA mostraram redução nas viscosidades de pico, de quebra e final e desenvolvimento de viscosidade inicial com o aumento do tempo de moagem. As temperaturas de gelatinização reduziram com o aumento do tempo de moagem bem como as variações de entalpia devido à dissociação das pontes de hidrogênio. Esses resultados confirmaram... / Starches with less extensive crystalline regions can be used in different industrial applications, since they have higher solubility, lower gelatinization temperature and higher reactivity. Heat-moisture treatment (HMT) and ball milling are physical modification methods that can result in changes in the crystalline region of the starch. The objective of this project was to investigate the physicochemical and structural changes caused by these treatments in Peruvian carrot and cassava starches. The HMT was performed with starch conditioned at 30 and 35% moisture and kept at 90 °C for 8 hours. The ball milling of starches was performed for 2, 4, 8, 16 and 32 hours. The physicochemical and structural characteristics of the starches were determined. The ball milling altered the properties of the starches, especially after 8 h. Results obtained from HPAEC-PAD, GPC and amylose content indicated a breaking of hydrogen bounds and α (1→6) glycoside linkages of the starch molecules. X-ray diffractograms showed that the crystalline area of the starch granules was reduced by the ball milling. Fissures in the granules were seen under SEM after milling and granule fragments were generated. There was an increase in the WSI and WAI of the starches that was positively correlated with an increase in the length of time that the starch was milled. RVA profiles showed a reduction of peak, breakdown, and final viscosities, as well as the development of initial viscosity. Gelatinization temperatures reduced as the starch’s amount of time in the ball milling increased, and there was also a reduction in enthalpy due to the dissociation of hydrogen bounds. These results confirmed a partial gelatinization of the starches, which was 82.57 % for Peruvian carrot and 65.37 % for cassava starches after 32 h of milling. The Peruvian carrot starch was the more... (Complete abstract click electronic access below)
3

Efeito da moagem em moinho de bolas e do tratamento térmico com baixa umidade sobre as características estruturais e físico-químicas dos amidos de mandioca e mandioquinha-salsa/

Moraes, Jaqueline de. January 2012 (has links)
Orientador: Célia Maria Landi Franco / Banca: Silene Bruder Silveira Sarmento / Banca: Fernanda Helena Gonçalves Peroni Okita / Resumo: Amidos com regiões cristalinas menos extensas podem ser usados em diversas aplicações industriais, pois apresentam maior solubilidade a frio, menor temperatura de gelatinização e maior reatividade. O tratamento térmico a baixa umidade (TTBU) e a moagem em moinho de bolas são métodos de modificação física que podem resultar em alterações na região cristalina dos amidos. O objetivo deste projeto foi investigar as alterações físico-químicas e estruturais provocadas pelos dois tratamentos em amidos de mandioquinha-salsa e mandioca. O TTBU foi realizado com amidos condicionados a 30 e 35 % de umidade a 90º C por 8 horas. A moagem em moinho de bolas dos amidos foi realizada durante 2, 4, 8, 16 e 32 horas. As propriedades físico-químicas e estruturais dos amidos foram determinadas. A moagem em moinho de bolas provocou alterações nas propriedades dos amidos, principalmente após 8 h de tratamento. Os resultados obtidos por HPAEC-PAD, GPC e teor de amilose indicaram o rompimento das pontes de hidrogênio e ligações glicosídicas α (1→6) das moléculas de amido. A partir dos difractogramas de raios-X foi observado que a área cristalina dos grânulos de amido reduziu com a moagem, o que foi confirmado pela redução da cristalinidade nos amidos moídos. Grânulos de ambos os amidos moídos a partir de 2 h apresentaram fissuras que foram observadas por MEV e fragmentos de grânulos foram gerados nos maiores tempos de moagem resultando no aumento do ISA e redução do IAA. Os perfis de RVA mostraram redução nas viscosidades de pico, de quebra e final e desenvolvimento de viscosidade inicial com o aumento do tempo de moagem. As temperaturas de gelatinização reduziram com o aumento do tempo de moagem bem como as variações de entalpia devido à dissociação das pontes de hidrogênio. Esses resultados confirmaram... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Starches with less extensive crystalline regions can be used in different industrial applications, since they have higher solubility, lower gelatinization temperature and higher reactivity. Heat-moisture treatment (HMT) and ball milling are physical modification methods that can result in changes in the crystalline region of the starch. The objective of this project was to investigate the physicochemical and structural changes caused by these treatments in Peruvian carrot and cassava starches. The HMT was performed with starch conditioned at 30 and 35% moisture and kept at 90 °C for 8 hours. The ball milling of starches was performed for 2, 4, 8, 16 and 32 hours. The physicochemical and structural characteristics of the starches were determined. The ball milling altered the properties of the starches, especially after 8 h. Results obtained from HPAEC-PAD, GPC and amylose content indicated a breaking of hydrogen bounds and α (1→6) glycoside linkages of the starch molecules. X-ray diffractograms showed that the crystalline area of the starch granules was reduced by the ball milling. Fissures in the granules were seen under SEM after milling and granule fragments were generated. There was an increase in the WSI and WAI of the starches that was positively correlated with an increase in the length of time that the starch was milled. RVA profiles showed a reduction of peak, breakdown, and final viscosities, as well as the development of initial viscosity. Gelatinization temperatures reduced as the starch's amount of time in the ball milling increased, and there was also a reduction in enthalpy due to the dissociation of hydrogen bounds. These results confirmed a partial gelatinization of the starches, which was 82.57 % for Peruvian carrot and 65.37 % for cassava starches after 32 h of milling. The Peruvian carrot starch was the more... (Complete abstract click electronic access below) / Mestre
4

Evaluation of pelleting process parameters on feed nutrients, starch gelatinization and pig growth performance

Lewis, Landon L. January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Cassandra Jones / In two experiments, conditioning time and temperature of swine feed were altered to determine effects of starch, vitamin retention, and swine growth performance. A third experiment evaluated methodologies for estimating gelatinized starch in swine feed. Across all experiments, diet formulation was constant. In Exp. 1, treatments were arranged in a 2 × 3 factorial design plus a control, including 2 conditioning temperatures (77 vs. 88°C) and 3 conditioner retention times (15, 30, and 60 s). A mash diet was added for a total of 7 treatments. Total starch was affected by conditioning temperature (P = 0.04) but not time (P = 0.50). Similar results were observed for gelatinized starch (P = 0.005 and 0.65, respectively). Sample location also affected total starch (P = 0.0002) and gelatinized starch (P = 0.0001), with the greatest increase in gelatinization occurring between conditioned mash and hot pellets. Conditioning alone did not influence gelatinization as evidenced by similar values between cold and hot mash (P > 0.05). Neither conditioning temperature nor time affected vitamin concentrations (P > 0.50). A portion of these treatments were then fed to 180 nursery pigs (PIC 327 × 1050; initially 12.6kg) in an 18-d study. Treatments included: 1) non-processed mash (negative control); 2) pelleted diet conditioned for 30 s (positive control); 3) pelleted diet conditioned for 15 s and reground; 4) pelleted diet conditioned for 30 s and reground, and 5) pelleted diet conditioned for 60 s and reground. Observed growth performance differences appear to be due to feed form, not conditioning time. Average daily gain and G:F did not differ (P > 0.12) between treatments, but ADFI was decreased (P = 0.03) as expected for pigs fed the positive control pelleted diet compared to all other diets. There were no differences (P > 0.05) in any growth performance variables amongst the three conditioning temperatures. In Exp. 3, it was determined that the method developed by Mason et al. (1982) was the best indicator of gelatinization in livestock feed. In summary, feed form, but not conditioning time affected gelatinized starch and swine growth performance.
5

Evaluation of micronized lentil and its utilization in low-fat beef burgers

Der, Tanya J. 13 September 2010
Dehulled seed from four lentil market classes (large- and small-sized green and red types) were tempered to15% moisture and micronized to a surface temperature of 135 °C, and their compositional, physical, and functional properties were investigated. Micronization of lentil modified starch- and protein-related properties. Approximately 2.5 to 5.6% of the starch was gelatinized following micronization. Differential scanning calorimetry (DSC) results showed a 13 to 40% decrease in heat enthalpy, and viscosity analysis (Rapid Visco Analyzer) showed a 21 to 55% increase in peak viscosity and a 1 to 3 °C reduction in pasting temperature. Nitrogen solubility decreased across the pH range of 2 to 9, and lipoxygenase activity was reduced by 100-fold. There was a 25 to 43% increase in water holding capacity with no change in oil absorption capacity. The colour intensity of the pigments in the green and red lentil were reduced upon micronization of seed, and the particle size of flour was lowered with 7 to 13% more flour passing into the finest (<75 um) sieve. Flours from dehulled green and red lentil (large type) were incorporated as a binder into low-fat (<10%) beef burgers at levels of 6 and 12%. Cooking properties, colour, texture, oxidative status, and sensory properties of these burgers were analyzed. Overall, increasing binder addition to low-fat beef burgers increased cooking yield up to 86% and minimized dimensional shrinkage upon cooking. Storage of raw, fresh burgers for 7 days under simulated retail display (4 °C) resulted in gradual reductions in HunterLab a* values, with those containing micronized lentil flour generally displaying significantly greater retention of redness from days 1 to 5 of storage. Thiobarbituric acid reacting substances (TBARS) of burgers containing micronized lentil flour were significantly lower compared with those containing non-micronized lentil after 9 to 11 weeks of frozen storage. A trained sensory panel (n=13) reported increasing burger juiciness and tenderness with the incorporation of up to 6% and 12% of lentil flour, respectively. Although off-flavour increased in burgers with non-micronized lentil flour addition, it was significantly reduced when seed was micronized. Consumer panel analysis (n=107) showed higher acceptability for burgers containing 6% micronized lentil flour or toasted wheat crumb compared with those containing non-micronized lentil flour or no binder. These results demonstrate that the conditions used to micronize lentil altered the functional properties of the flours, and when used as a meat binder at an optimal level improved cooking properties, texture, and flavour profiles in low-fat beef burgers.
6

Evaluation of micronized lentil and its utilization in low-fat beef burgers

Der, Tanya J. 13 September 2010 (has links)
Dehulled seed from four lentil market classes (large- and small-sized green and red types) were tempered to15% moisture and micronized to a surface temperature of 135 °C, and their compositional, physical, and functional properties were investigated. Micronization of lentil modified starch- and protein-related properties. Approximately 2.5 to 5.6% of the starch was gelatinized following micronization. Differential scanning calorimetry (DSC) results showed a 13 to 40% decrease in heat enthalpy, and viscosity analysis (Rapid Visco Analyzer) showed a 21 to 55% increase in peak viscosity and a 1 to 3 °C reduction in pasting temperature. Nitrogen solubility decreased across the pH range of 2 to 9, and lipoxygenase activity was reduced by 100-fold. There was a 25 to 43% increase in water holding capacity with no change in oil absorption capacity. The colour intensity of the pigments in the green and red lentil were reduced upon micronization of seed, and the particle size of flour was lowered with 7 to 13% more flour passing into the finest (<75 um) sieve. Flours from dehulled green and red lentil (large type) were incorporated as a binder into low-fat (<10%) beef burgers at levels of 6 and 12%. Cooking properties, colour, texture, oxidative status, and sensory properties of these burgers were analyzed. Overall, increasing binder addition to low-fat beef burgers increased cooking yield up to 86% and minimized dimensional shrinkage upon cooking. Storage of raw, fresh burgers for 7 days under simulated retail display (4 °C) resulted in gradual reductions in HunterLab a* values, with those containing micronized lentil flour generally displaying significantly greater retention of redness from days 1 to 5 of storage. Thiobarbituric acid reacting substances (TBARS) of burgers containing micronized lentil flour were significantly lower compared with those containing non-micronized lentil after 9 to 11 weeks of frozen storage. A trained sensory panel (n=13) reported increasing burger juiciness and tenderness with the incorporation of up to 6% and 12% of lentil flour, respectively. Although off-flavour increased in burgers with non-micronized lentil flour addition, it was significantly reduced when seed was micronized. Consumer panel analysis (n=107) showed higher acceptability for burgers containing 6% micronized lentil flour or toasted wheat crumb compared with those containing non-micronized lentil flour or no binder. These results demonstrate that the conditions used to micronize lentil altered the functional properties of the flours, and when used as a meat binder at an optimal level improved cooking properties, texture, and flavour profiles in low-fat beef burgers.
7

Umidade da massa no extrusor sobre os parâmetros de processamento, macroestrutura, cozimento do amido e palatabilidade de alimentos extrusados para gatos. / In-barrel moisture on the parameters of extrusion process, macroestruture, starch gelatinization and palatability on extruded food for cats

Baller, Mayara Aline 23 February 2017 (has links)
Submitted by MAYARA ALINE BALLER null (mayara.baller@hotmail.com) on 2018-03-27T18:13:55Z No. of bitstreams: 1 Dissertação_Mayara_Aline_Baller.pdf: 1097419 bytes, checksum: 1ed29fabe4f9766088f4c08034fb44bb (MD5) / Rejected by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br), reason: Solicitamos que realize correções na submissão seguindo as orientações abaixo: No arquivo pdf submetido ao repositório não consta o certificado de aprovação (parte obrigatória). Peço o favor de inserir o mesmo no arquivo pdf e posteriormente faça uma nova submissão. Agradecemos desde já a compreensão. on 2018-03-28T12:44:35Z (GMT) / Submitted by MAYARA ALINE BALLER null (mayara.baller@hotmail.com) on 2018-04-02T19:57:16Z No. of bitstreams: 1 Definitivo_Mayara_Aline_Baller.pdf: 1118401 bytes, checksum: a6ef83398402780f3bf51364be72e883 (MD5) / Approved for entry into archive by Alexandra Maria Donadon Lusser Segali null (alexmar@fcav.unesp.br) on 2018-04-03T10:44:39Z (GMT) No. of bitstreams: 1 baller_ma_me_jabo.pdf: 1118401 bytes, checksum: a6ef83398402780f3bf51364be72e883 (MD5) / Made available in DSpace on 2018-04-03T10:44:39Z (GMT). No. of bitstreams: 1 baller_ma_me_jabo.pdf: 1118401 bytes, checksum: a6ef83398402780f3bf51364be72e883 (MD5) Previous issue date: 2017-02-23 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / A adição de água é uma das variáveis que otimiza o processo de extrusão, uma vez que favorece o umedecimento dos ingredientes e transferência de calor, proporcionando o cozimento adequado; ocasiona mudanças na viscosidade e nas características macroestruturais dos kibbles reduzindo o desgaste da rosca extrusora; e se adicionada em quantidades suficientes, diminui a taxa de ocorrência da reação de Maillard. Apesar de sua importância, não se localizaram estudos sobre os melhores intervalos de umidade de processamento para a produção de rações para gatos. O objetivo deste trabalho foi avaliar os efeitos da umidade da massa no canhão da extrusora sobre os parâmetros de processamento, macroestrutura dos kibbles, balanço de massa e energia, gelatinização do amido e teor de lisina reativa em alimentos extrusados para gatos. Uma fórmula padrão para gatos foi extrusada, e durante o processo de extrusão foram adicionadas seis diferentes quantidades de água no canhão extrusor, correspondendo as umidades da massa de 22%, 27%, 30%, 32%, 35% e 37% (tratamentos). O alimento foi produzido em extrusora de rosca simples e as condições de processamento foram estabilizadas para a dieta 22%, não sendo alteradas para as demais dietas. Os parâmetros registrados foram a temperatura do pré-condicionador, temperatura, pressão e produtividade da extrusora. Amostras de ração foram coletados a cada 15 minutos na saída da extrusora, sendo considerado cada coleta uma unidade experimental. A energia mecânica específica e a energia térmica específica, transferidas à massa, foram calculadas de acordo com Riaz (2007). A lisina reativa foi avaliada pelo método da O-metilisoureia (Moughan e Rutherfurd, 1996). Os dados obtidos foram submetidos à análise de variância (ANOVA) e as médias comparadas por contrastes polinomiais (P<0,05). A adição de água aumentou a umidade de processamento de forma linear (P<0,001), o que resultou em diminuição da pressão e temperatura de extrusão, redução quadrática da aplicação de energia mecânica específica (EME) (P<0,001), redução quadrática na densidade aparente e específica, e na expansão radial e longitudinal (P<0,01), sem alterar a força de ruptura e a gelatinização do amido das dietas. Houve ainda um aumento da lisina ligada, indicando maior complexação do aminoácido (P<0,001). Conclui-se que uma elevada umidade da massa no canhão leva à uma redução da EME, da temperatura, da pressão, da gelatinização do amido, explicado pelo aumento da fluidez da massa e consequente reduz do cisalhamento. Por outro lado, a baixa umidade da massa reduziu a expansão, a temperatura e o flash-off ou vaporização da água, fenômeno chave na formação celular e expansão do extrusado. / The addition of water is one of the variables that maximizes the extrusion process, since it favors the hydration of the ingredients and the heat transfer, providing a proper cooking; it also causes changes in the viscosity and macrostructural characteristics of the kibbles, reducing the wear of the extruder thread; if added in sufficient amounts it decreases the occurrence of Maillard reaction. Despite their importance, there are no studies evaluating the best processing moisture ranges for the production of cat food. The objective of this work was to evaluate the effects of the in-barrel moisture on the processing parameters, kibble macrostructure, mass and energy balance, starch gelatinization and reactive lysine content of extruded foods for cats. A standard formula for cats was extruded, and during the extrusion process six different amounts of water were added to the extruder barrel, corresponding to the moistures of22%, 27%, 30%, 32%, 35% and 37% (treatments).The feed was extruded in a single screw extruder and the processing conditions were stabilized for the 22% diet, they were not changed for the other diets. The productivity, pressure and temperatures of the conditioner and of the extruder were recorded. Feed samples were collected every 15 minutes at the end of the extruder, each sample was considered an experimental unit. The specific mechanical energy and specific thermal energy transferred to the mass were calculated according to Riaz (2007). The reactive lysine was evaluated by the O-methylisourea method (Moughan and Rutherfurd, 1996). The data were submitted to analysis of variance (ANOVA) and the means were compared by polynomial contrasts (P <0.05). Addition of water linearly increased the processing moisture (P <0.001), which resulted in a decrease in extrusion pressure and temperature, quadratic reduction of specific mechanical energy application (P <0.001), quadratic reduction in density apparent and specific, radial and longitudinal expansion (P <0.01), without altering the breaking strength and the starch gelatinization of the diets. There was also an increase in the bound lysine indicating greater amino acid complexation (P <0.001). It is concluded that an increase in in-barrel moisture leads to a reduction in the EME, the temperature, the pressure, the starch gelatinization, explained by the increase of the fluidity mass and consequent reduction of the shear. On the other hand, a low in-barrel moisture reduced expansion, a temperature and flash off, a key phenomenon in the cell formation and expansion of the extrudate.
8

Impacto do tratamento térmico com baixa umidade sobre as características físico-químicas e reológicas de amidos de mandioca, araruta e mandioquinha-salsa

Pepe, Larissa da Silva [UNESP] 26 August 2011 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:23:27Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-08-26Bitstream added on 2014-06-13T20:50:21Z : No. of bitstreams: 1 pepe_ls_me_sjrp.pdf: 529766 bytes, checksum: cc5fdbb13244fca1f8f61305ceac4a93 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Estabilidade de amidos frente a altas temperaturas e cisalhamento pode ser melhorada com o tratamento térmico com baixa umidade (TTBU). O objetivo deste trabalho foi investigar o efeito do TTBU sobre as características físico-químicas e reológicas dos amidos de mandioca, araruta e mandioquinha-salsa. Os amidos foram isolados e analisados quanto à composição química, teor de amilose e comprimento de cadeias ramificadas de amilopectina. Amostras de amido foram condicionadas a 28 % de umidade e submetidas a 100 ºC por 2, 4, 8 e 16 h. Os amidos nativos e modificados foram analisados quanto à morfologia dos grânulos, difração de raio-X, propriedades de pasta e térmicas, índices de absorção de água (ISA) e solubilidade (ISA) em água a 30 ºC e poder de inchamento (PI) e solubilidade (S) a 95 ºC. A transparência e sinérese dos géis de amidos nativos e modificados por 4 h, submetidos ou não a acidez e esterilização foram determinadas, e ensaios reológicos estacionários e oscilatórios dos géis foram realizados. O amido de mandioquinha-salsa apresentou o menor teor de amilose e maior proporção de defeitos em sua estrutura cristalina quando comparado com os outros amidos. O TTBU não afetou a morfologia dos grânulos, mas modificou o padrão cristalino dos amidos de mandioca e araruta de CA para A, e do amido de mandioquinha-salsa de B para A. Houve redução efetiva na viscosidade de quebra e aumento no set back das pastas de amido. As temperaturas de gelatinização aumentaram e os picos endotérmicos mostraram-se mais largos, enquanto as entalpias, o PI e a S dos amidos reduziram com o TTBU. Esses resultados sugeriram que o tratamento provocou uma reorganização das cadeias de amido aumentando as interações moleculares. A estrutura cristalina livre de defeitos e as forças associativas mais fortes presentes no amido de araruta contribuíram para que este fosse menos... / Stability of starch in the face of high temperatures and shear can be improved by heat-moisture treatment (HMT). The objective of this study was to investigate the effect of HMT on physicochemical characteristics and rheological properties of starches from cassava, arrowroot and peruvian carrot. Starches were isolated and analyzed for chemical composition, amylose content and length of branched chains of amylopectin. Starches were conditioned at 28 % moisture and kept at 100 ºC for 2, 4, 8 and 16 h. The native starches and modified samples were analyzed for the morphology of the granules, diffraction of X-ray, pasting and thermal properties, index of water absorption (IWA) and solubility (IWS) in water at 30 ºC and swelling power (SP) and solubility (S) at 95 ºC. Transparency and syneresis of gels of native and modified starches for 4 h submitted or not to sterilization and acidity were determined, and stationary and oscillatory rheological tests were carried out of the gels. The Peruvian carrot starch had the lowest amylose content and higher proportion of defects in their crystal structure when compared with other starches. The HMT did not affect the morphology of granules, but changed the crystalline pattern of cassava and arrowroot starch from CA to A, and Peruvian carrot starch from B to A. There was a reduction effective in the breakdown viscosity and set back, and increase in the pasting of starches. The increased gelatinization temperatures and endothermic peaks were shown to be wider, while the enthalpies, SP and S starches with reduced with HMT. These results suggested that treatment caused a reorganization of the starch chains increases the molecular interactions. The crystal structure free of defects and stronger associative forces present in the arrowroot starch contributed to this were less affected by treatment. The gels of arrowroot and peruvian carrot modified... (Complete abstract click electronic access below)
9

Selênio e mucosa intestinal e cozimento do amido, digestibilidade dos nutrientes e produtos de fermentação nas fezes de cães / Selenium and intestinal mucosa and starch cooking, nutrient digestibility and fecal fermentation products of dogs

Oliveira, Michele Cristina de Camargo [UNESP] 06 June 2016 (has links)
Submitted by MICHELE CRISTINA DE CAMARGO OLIVEIRA null (michelecrisco@yahoo.com.br) on 2016-07-25T20:34:19Z No. of bitstreams: 1 Tese - Michele Oliveira.pdf: 1504288 bytes, checksum: 916801277367906d52bd367af3a0124d (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-07-29T12:14:04Z (GMT) No. of bitstreams: 1 oliveira_mcc_dr_jabo.pdf: 1504288 bytes, checksum: 916801277367906d52bd367af3a0124d (MD5) / Made available in DSpace on 2016-07-29T12:14:05Z (GMT). No. of bitstreams: 1 oliveira_mcc_dr_jabo.pdf: 1504288 bytes, checksum: 916801277367906d52bd367af3a0124d (MD5) Previous issue date: 2016-06-06 / Este trabalho incluiu um estudo sobre os efeitos da adição de selênio em dietas secas extrusadas na mucosa intestinal de cães. Utilizou-se uma única formulação para produzir cinco dietas sendo uma dieta controle com adição de 0,13ppm de selenito de sódio, uma segunda dieta com 0,33ppm de selênio levedura, outra com 0,66ppm de selênio levedura, a quarta contendo 0,99ppm de selênio levedura e a quinta com 0,66ppm de selenito de sódio. Foram utilizados 30 cães em três blocos de 10 cães e cada período teve duração de 210 dias incluindo adaptação e fase experimental. Ao final de cada período foram coletadas amostras de mucosa do trato gastrintestinal por endoscopia e colonoscopia para avaliação. Um segundo estudo avaliou o efeito da gelatinização do amido na digestibilidade aparente dos nutrientes, produção de fezes e produtos de fermentação de cães alimentados com dietas extrusadas incluindo dois estudos. No estudo 1 uma mesma formulação foi processada de quatro maneiras diferentes resultando em três dietas extrusadas com moagens de 0.5, 1.8 e 2.0 mm e uma dieta peletizada com moagem de 1.8mm com diferentes graus de gelatinização. Foram utilizados 24 cães, seis por tratamento e avaliou-se a digestibilidade e os produtos de fermentação. No estudo 2 foi utilizada uma base de dados publicados e a digestibilidade de dietas preparadas para construir regressões polinomiais entre o grau de gelatinização do amido e a digestibilidade aparente dos nutrientes. No primeiro estudo a análise histológica demonstrou diferença significativa com a dieta suplementada com selênio orgânico 0,66ppm comparado com as dietas suplementadas com selênio orgânico 0,33ppm e 0,99ppm. Não houve diferença entre as dietas suplementadas e a dieta controle. É possível que a suplementação de selênio possa trazer benefícios a saúde intestinal. No estudo 1 do segundo estudo houve aumento linear da proteína bruta (p<0.002), e aumento quadrático da digestibilidade do amido (p<0.001) seguindo o aumento da gelatinização do amido das dietas. As concentrações fecais de acetato, propionato, butirato, ácido valérico e isobutírico reduziram linearmente enquanto o lactato reduziu quadraticamente com aumento da gelatinização do amido (p<0.001). No estudo 2 a digestibilidade da matéria orgânica (R2 de 0,63 a 0,26), proteína bruta (R2 de 0,91 a 0,26), amido ou extrativos não nitrogenados (R2 de 0,95 a 0,23), e gordura (R2 d 0,84 a 0,46) aumentou com a maior gelatinização do amido (p<0.05). A digestibilidade da proteína parece ser mais influenciada pela gelatinização do amido. A gelatinização do amido entre 83% a 87% parece ser capaz de maximizar a digestibilidade aparente dos nutrientes. / This work included a study on the effects of the addition of selenium in extruded dry diets in the gastrointestinal tract of dogs. It was used a single formulation to produce five diets and a control diet with the addition of 0,13ppm sodium selenite, a second diet with selenium yeast of 0,33ppm, another diet with 0,66ppm selenium yeast, the fourth diet containing 0, 99ppm of selenium yeast and the fifth with 0,66ppm sodium selenite. It was used a total of 30 dogs in three blocks of 10 dogs and each period lasted 210 days including adaptation and experimental phase. At the end of each period mucosa samples were collected from the gastrointestinal tract by endoscopy and colonoscopy for evaluation. A second study evaluated the effect of starch gelatinization in the apparent digestibility of nutrients, production of feces and dog fermentation products fed extruded diets including two studies. In Study 1 the same formulation was processed in four different ways, resulting in three extruded diets of grindings 0.5, 1.8 and 2.0 mm and a pelleted diet with grinding of 1.8mm with different degrees of gelatinization. Twenty-four dogs were used, six dogs per treatment and digestibility and fermentation products were evaluated. In the second study it was used a published database and diet digestibility prepared to construct polynomial regressions between the degree of starch gelatinization and apparent nutrient digestibility. In the first study histological analysis showed a significant difference with the diet supplemented with organic selenium 0,66ppm compared with the diets supplemented with organic selenium 0,33ppm and 0,99ppm. There was no difference between the supplemented diets and the control diet. It is possible that selenium supplementation may benefit intestinal health. In Study 1 of the second study crude protein increased linearly (p <0.002), and starch digestibility increase quadratically (p <0.001) following the increased starch gelatinization. Fecal concentrations of acetate, propionate, butyrate, isobutyric acid and valeric reduced linearly while the lactate reduced quadratically with an increase in starch gelatinization (p <0.001). In study 2 the organic matter digestibility (R2 0.63 to 0.26), crude protein (R2 0.91 to 0.26), starch or nitrogen free extract (R2 .95 to .23) and fat (R2 0.84 to 0.46) increased with higher starch gelatinization (p <0.05). The digestibility of the protein seems to be more influenced by gelatinization. The gelatinization from 83% to 87% seems to be able to maximize the apparent digestibility of nutrients.
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Caracterização estrutural e físico-química do amido de taioba (Xanthosoma sagittifolium ) e potencial aplicação na produção de etanol / Structural and physico-chemical characterization of tannia starch (Xanthosoma sagittifolium) and potential application in the production of ethanol

Farias, Flávia de Aquino Cutrim [UNESP] 29 June 2017 (has links)
Submitted by FLÁVIA DE AQUINO CUTRIM FARIAS null (flavia_cutrim@ifma.edu.br) on 2017-07-04T12:32:45Z No. of bitstreams: 1 TESE-FLÁVIA CUTRIM Farias (1).pdf: 1973425 bytes, checksum: b19b213ea6c0f5ad7bd758faa989e1f7 (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-07-04T18:19:07Z (GMT) No. of bitstreams: 1 farias_fac_dr_sjrp.pdf: 1973425 bytes, checksum: b19b213ea6c0f5ad7bd758faa989e1f7 (MD5) / Made available in DSpace on 2017-07-04T18:19:07Z (GMT). No. of bitstreams: 1 farias_fac_dr_sjrp.pdf: 1973425 bytes, checksum: b19b213ea6c0f5ad7bd758faa989e1f7 (MD5) Previous issue date: 2017-06-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Há um grande interesse em se produzir álcool por matérias-primas alternativas à cana-de-açúcar. As fontes amiláceas tropicais são alvos potenciais nestas pesquisas. A taioba é uma planta que contem um teor considerável de amido nos seus tubérculos, mas é pouco explorada cientifica e comercialmente. Este trabalho teve como objetivo avaliar o potencial industrial da taioba. Para isto, determinaram-se as características estruturais e físico-químicas do amido de taioba, e, em seguida, se avaliou o potencial para a produção de etanol. Todas as analises foram realizadas em comparação ao amido de mandioca, por ser uma fonte conhecida e bem difundida no Brasil. Os amidos apresentaram alto grau de pureza e baixo teor de fósforo (< 0,05%). O amido de taioba apresentou 21,80 % de amilose aparente e 16,96 % de amilose absoluta. Os amidos exibiram perda de água (sinérese) durante a estocagem em todas as temperaturas testadas, mas a menor porcentagem de perda em ambos os amidos foi a 25 °C. O amido de taioba apresentou temperaturas de gelatinização mais elevadas, maiores alterações de entalpia de gelatinização e maiores percentagens de retrogradação, mas com valores de hidrólise menores que o amido de mandioca, sendo que essas diferenças podem ser atribuídas à menor proporção de cadeias ramificadas curtas (DP 6-12) da amilopectina e à maior viscosidade final do amido de taioba. O amido de taioba foi sacarificado enzimaticamente e submetido à fermentação usando a levedura Saccharomyces cerevisiae JP1. A concentração máxima de etanol produzida foi de aproximadamente de 56,34 e 48,38 g.L-1, com produtividade de 0,67 e 0,56 g.L-1.h-1 e rendimentos na faixa de 0,49 e 0,46 para os hidrolisados de mandioca e taioba, respectivamente. A eficiência de conversão em álcool dos hidrolisados de mandioca foi de 96,8 % e taioba de 89,57 %. Este estudo obteve resultados inéditos e úteis para avaliar o emprego de tubérculo de taioba para desenvolvimento de produtos de valor agregado destinados a alimentos e combustível. / There is a great interest in producing alcohol for raw materials that are alternative to sugarcane. Tropical amylaceous sources are potential targets in these surveys. Tannia is a plant that contains a considerable amount of starch in its tubers, but is little explored scientifically and commercially. This work aimed to evaluate the industrial potential of this plant. For this, the structural and physicochemical characteristics of the tannia starch were determined, and then the potential for the production of ethanol was evaluated. All the analyzes were carried out in comparison to cassava starch, because it is a known and well-known source in Brazil. The starches presented high purity and low phosphorus content (<0.05%). Tannia starch had 21.80% apparent amylose and 16.96% absolute amylose. Starches exhibited loss of water (syneresis) during storage at all temperatures tested, but the lowest percentage loss in both starches was at 25 oC. Tannia starch showed higher gelatinization temperatures, greater gelatinization enthalpy changes and higher percentages of retrogradation, but with hydrolysis values lower than cassava starch, and these differences can be attributed to the lower proportion of short branched chains (DP 6-12) of the amylopectin and the higher final viscosity of the tannia starch. The tannia starch was saccharified enzymatically and subjected to fermentation using the yeast Saccharomyces cerevisiae JP1. The maximum concentration of ethanol produced was approximately 56.34 and 48.38 g.L-1, with yields of 0.67 and 0.56 gL-1.h-1 and yields in the range of 0.49 and 0.46. For the cassava and tannia hydrolysates, respectively. The alcohol conversion efficiency of cassava hydrolysates was 96.8% and tannia 89.57%. This study has obtained unpublished and useful results to evaluate the use of tuber tubers for the development of value-added products for food and fuel.

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