<p dir="ltr">Baked goods are one of the primary sources of added sugar in the American diet. Excessive consumption of added sugar can lead to diseases such as obesity, heart disease, and diabetes. As information pertaining to the link between health and diet becomes more available to consumers, the demand for products with lower calories, fat, and sugar continues to rise. The obstacle in formulating baked goods with alternative sweeteners is that these sweeteners have different effects on the physicochemical properties of the starch in the products than that of sucrose, leading to differences in texture, color (browning), texture, and flavor between the sucrose-containing products consumers are accustomed to and the new reduced sugar products. Previous studies done by the Mauer lab have found that interactions between the sweeteners that enter the amorphous region of the starch granule alter physicochemical properties of the starch, including the gelatinization temperature (T_gel) and pasting properties of the starch. The purpose of this project was to investigate how the presence of oligosaccharides (OS) used as sucrose replacers in starch-containing products alters the functionality of the starch through modification of its thermal and physicochemical properties. Different botanical sources of starch were preconditioned in solutions containing different concentrations of select OS, varying temperature during preconditioning. The preconditioned starches were then analyzed by differential scanning calorimetry (DSC), rapid visco analysis (RVA), and x-ray diffraction (XRD). Results demonstrated that several OS are less effective plasticizers of starch (all botanical sources) than sucrose, meaning T_gel is higher in the presence of these OS and less pasting occurs. This is advantageous for formulating low moisture baked goods that rely on inhibition of starch gelatinization for desirable product quality.</p>

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2016-09-08T17:28:17Z No. of bitstreams: 2 Dissertação - Raíza Cavalcante Fonseca - 2015.pdf: 1824882 bytes, checksum: 29667e889a40dc94517acb650bb67891 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-09-09T14:42:06Z (GMT) No. of bitstreams: 2 Dissertação - Raíza Cavalcante Fonseca - 2015.pdf: 1824882 bytes, checksum: 29667e889a40dc94517acb650bb67891 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-09-09T14:42:06Z (GMT). No. of bitstreams: 2 Dissertação - Raíza Cavalcante Fonseca - 2015.pdf: 1824882 bytes, checksum: 29667e889a40dc94517acb650bb67891 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2015-09-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The factors that control the rice cooking behavior are related to the physicochemical characteristics of the grain. The information of these traits is important to understanding the changes undergone by food during the cooking process. The objective of this work was to understand culinary behavior of upland rice genotypes with different levels of amylose through the characterization of physical, physicochemical, genetic and cooking quality of grain, as well as linking these factors to each other in order to point out reliable and reproducible indicators. We have analyzed eleven upland rice genotypes from the 2013 crop season at Embrapa Rice and Beans regarding the physical grain quality traits (head rice yield, grain size, percentage of chalk, milling degree), starch granule properties (morphology of the starch granules, swelling power, apparent amylose and absolute gelatinization temperature by alkaline dispersion, thermal properties by differential scanning calorimetry, pasting properties, the size distribution of amylopectin branched chains) and cooking quality (texture: hardness and stickiness of cooked grains (by cooking and instrumental tests) and of rice RVA gel). For genomic analysis, eight molecular markers associated to the cooking quality profile and described in the international literature were used. This study resulted in reliable and reproducible indicators of food quality for upland rice, to predict the culinary behavior profile were identified as key: the amylose content, gelatinization temperature, paste properties, instrumental texture properties and sensory of grains. In relation to validation markers for grain quality, it is concluded that the information derived from the analysis of association was possible to identify markers associated with cooking and technological attributes as well as to these favorable alleles. The final considerations involved in this study indicate that for different stages of breeding programs to launch on the market are cultivars of different analyzes displayed until the last assay which involves growing and use value. / Os fatores que controlam o comportamento culinário do arroz estão relacionados às características físico-químicas do grão. A informação dessas características é importante para a compreensão das modificações pelas quais passa o alimento durante o processo de cozimento. O objetivo deste trabalho foi compreender o comportamento culinário de genótipos de arroz de terras altas com diferentes teores de amilose por meio da caracterização dos parâmetros físicos, físico-químicos, genéticos e culinários da qualidade de grãos, bem como, associar esses fatores entre si de forma a apontar indicadores confiáveis. Foram analisados onze genótipos de plantio de terras altas provenientes da safra 2013 da Embrapa Arroz e Feijão quanto à qualidade física dos grãos (renda, rendimento, dimensão, porcentagem de gessados, grau de polimento), propriedades do grânulo de amido (morfologia dos grânulos de amido, poder de inchamento, teor de amilose aparente e absoluto, temperatura de gelatinização por dispersão alcalina, propriedades térmicas por calorimetria diferencial, propriedades de pasta, distribuição dos comprimentos de cadeias ramificadas da amilopectina) e qualidade culinária (textura: dureza e pegajosidade dos grãos cozidos (teste de cocção e instrumental) e do gel das pastas de arroz). Para a análise genômica, foram utilizados oito marcadores moleculares relacionados ao comportamento da qualidade culinária descritos na literatura internacional. Este estudo resultou em indicadores confiáveis e reprodutíveis da qualidade culinária para arroz de terras altas, para predizer o perfil de comportamento culinário foram apontados como principais: o teor de amilose, a temperatura de gelatinização, propriedades de pasta, propriedades de textura instrumental e sensorial dos grãos. Em relação à validação de marcadores para qualidade de grãos, conclui-se que a partir das informações derivadas da análise de associação foi possível a identificação de marcadores associados a atributos culinários e tecnológicos, assim como alelos favoráveis a estes. As considerações finais envolvidas neste estudo indicam que para diferentes etapas de programas de cruzamentos para o lançamento de cultivares no mercado são indicadas diferentes análises até o último ensaio que envolve o valor de cultivo e uso.