LFY of Arabidopsis is a member of a unique plant specific transcription factor family. It is involved in giving meristem a determinate floral fate by the activation of floral organ identity genes and preventing inflorescence meristem identity. RFL is a homolog of FLO/LFY in rice. Studies from our lab on rice RFL, based on the effects of knockdown or overexpression, showed its major functions are in timing the conversion of SAM to IM and to prevent the premature conversion of branch meristem to spikelets. Additionally roles in vegetative axillary meristem specification have been also been identified in laboratory. Here, we attempt to delineate molecular pathways directly regulated by RFL as a transcription factor controlling inflorescence and floral development in rice. Part I: Identification of global target genes bound by RFL in developing rice inflorescences We carried out ChIP sequencing of the DNA bound by RFL in panicles (01.-0.3cm stage) using anti-RFL antibody. DNA sequences in one library pool were analyses by the MACS algorithm (FDR<0.01), to find 8000 binding sites while the SPP algorithm identified 5000 enriched peaks. These mapped to 2500 or 2800 gene-associated loci respectively, 617 of which were common loci to both pipelines. Several RFL bound gene loci were homologs of Arabidopsis thaliana LFY gene targets. Such gene targets underscore conserved downstream targets for LFY-proteins in evolutionarily very distinct species. AtLFY is known to bind variants of CCANT/G cis element classified as primary, inflorescence or seedling type. We scanned for these three types of cis elements at 123 RFL bound genes with likely functions in flowering. For a few of these 123 rice loci we find one of these cis motifs (p-value<0.001) in RFL bound ChIP-seq data. To validate these targets of RFL, we adopted in vitro DNA-protein binding assays with bacterially purified RFL protein. We confirm RFL target interactions with some genes implicated in flowering time, others in photoperiod triggered flowering, circadian rhythm, gibberellin hormone pathway, inflorescence development and branching. The in vitro experiments hint different RFL-DNA binding properties as compared to Arabidopsis LFY. We report binding to sequences at rice gene loci that are unique targets. Part II: Pathways regulated by RFL for reproductive transition and panicle development To co-relate DNA binding of RFL to target loci with changes in their gene expression, expression studies were taken up for selected set of genes implicated in rice flowering transition and panicle architecture. To study in planta and tissue specific gene regulation by RFL we raised RFL dsRNAi transgenics. Comparative transcript analysis in these RFL partial knockdown lines and matched wild type tissues reveal that RFL is an activator for some genes and repressor for other gene targets. We also examined if the gene expression effects of RFL knockdown can be reversed by induced complementation with an RFL-GR protein. We raised transgenics plants with a T-DNA ubi:RFL-GR, 35S CaMV:amiR RFL for these experiments. In planta target gene transcript levels were assessed in various conditions conditions. These studies validate rice RFL as an activator of some panicle architecture genes. Part III: Analysis of endogenous RFL protein in WT rice tissues Studies in Arabidopsis and in petunia with LFY and AFL, respectively, implicate these some abnormal mobility as compared to their predicted molecular weight when overexpressed. We studied endogenous RFL protein abundance in planta, adopting western analysis with anti-RFL antibody. We consistently identify two prominent cross reacting bands in different tissues which can be also be pulled-down from whole nuclear extracts of panicle and axillary meristem tissues. We speculate on likely modifications and possible functions for the same.

Genetic resources are important for the development of every country and for humanity. Collection, conservation and reasonable utilization of genetic resource is required mission. Understanding the importance of genetic resource, especially rice germplasm, since 2001, Center for conservation and development of crop genetic resources (CCD-CGR) of Hanoi University of Agriculture (Vietnam National University of Agriculture) has been collected, conserved and evaluated rice germplasm from different provinces of Vietnam for breeding programs. So far, 1090 accessions of local rice of Vietnam have been collected. Evaluation of agronomic properties and screening of some important genes using DNA molecular markers have revealed that Vietnamese rice germplasm has high level diversity and containing important genes for quality and resistance for disease and pests. These genetic resources are potential materials for national breeding programs. Based on the collected germplasm, 3 new glutinous rice varieties have been successfully created with high yield and good quality. In addition, the degradation of local rice varieties is also a matter of concern. So far, 4 specialty rice varieties Deo Dang, Ble chau, Pu de and Khau dao have been successfully restored for the north provinces of Vietnam. The main results of this study are germplasms for rice breeding programs and new improved varieties that bring economic benefits to farmers and the country. / Nguồn gene là tài nguyên sống còn của mỗi quốc gia và của toàn nhân loại. Vì vậy thu thập, bảo tồn, đánh giá và khai thác hợp lý nguồn tài nguyên này có ý nghĩa rất lớn. Nhận thức được tầm quan trọng của nguồn gen nhất là nguồn gen cây lúa, ngay từ đầu những năm 2000, Trung tâm bảo tồn và phát triển nguồn gene cây trồng thuộc Trường Đại học nông nghiệp, nay là Học Viện nông nghiệp Việt Nam đã tiến hành thu thập, lưu giữ, đánh giá và khai thác nguồn gene lúa. Kết quả đã thu thập, lưu giữ được 1090 mẫu giống lúa địa phương Việt Nam. Đánh giá đặc điểm nông sinh học và phát hiện một số gene quy định các tính trạng chất lượng và kháng sâu bệnh bằng chỉ thị phân tử DNA. Đây là nguồn gene quan trọng cho chọn tạo giống. Dựa vào nguồn gene thu thập được, cho đến nay, Trung tâm bảo tồn và phát triển nguồn gene cây trồng đã lai và chọn tạo được thành công 03 giống lúa nếp chất lượng cao. Ngoài ra, thoái hóa giống cũng là vấn đề đang được quan tâm. Cho đến nay 4 giống lúa đặc sản Đèo đàng, Ble châu, Pu đe và Khẩu dao đã được phục tráng và đưa vào sản xuất. Kết quả của những nghiên cứu này là ngân hàng các giống lúa làm nguồn gene để chọn tạo giống mới đem lại lợi ích kinh tế cho người nông dân và đất nước.

O Brasil é um grande produtor de commodities alimentícias, e hoje o desenvolvimento da indústria de ingredientes para a geração de insumos de maior valor agregado a partir destas matérias-primas é uma área pouco explorada pelas indústrias brasileiras. O arroz se destaca no agronegócio brasileiro, já que o país figura como o nono maior produtor mundial. O arroz quebrado é um coproduto do beneficiamento do arroz branco polido. Este estudo teve como objetivo propor e avaliar um processo de obtenção de concentrados e hidrolisados proteicos de arroz, contribuindo na oferta de estratégias para o desenvolvimento tecnológico do setor no Brasil. Adicionalmente, deseja-se auxiliar na valoração do coproduto arroz quebrado, alimento de baixo valor comercial, base para a geração de matérias-primas já encontradas internacionalmente, e que apresentam grande potencial de desenvolvimento no mercado brasileiro. Dentro deste contexto, buscou-se estudar a aplicação da tecnologia de membranas neste processo, por ser uma tecnologia limpa, de baixo consumo energético, já bem estabelecida e com aplicações crescentes na indústria de alimentos. O estudo iniciou com a avaliação da eficácia de um método rápido de extração alcalina de amido e proteína de arroz, no qual foi utilizada farinha de arroz derivada de arroz quebrado como matéria-prima, ao invés dos grãos quebrados, como no método tradicional. Nesse estudo, a partir do uso de uma razão substrato:solvente de 1:15, a etapa de extração foi realizada em estágio único a 30 oC em apenas 30 minutos – um curto tempo de extração se comparado ao método alcalino tradicional (24-48h). O rendimento da extração proteica com estas condições foi bastante elevado, atingiu 81,4 %. Observou-se ser possível realizar uma extração eficiente, com a minimização das reações indesejadas causadas pelo meio alcalino. Na segunda etapa foram avaliadas as propriedades funcionais do concentrado proteico obtido a partir do método rápido de extração alcalina. Além disso, suas propriedades foram comparadas com as de dois concentrados proteicos comerciais produzidos por extração enzimática. Foi observado que todos os concentrados proteicos avaliados apresentaram pobres propriedades funcionais, devido sobretudo a suas baixas solubilidades em condições de pH próximas à neutralidade e levemente ácidas, concluindo-se ser necessário estudos que visem a melhoria da solubilidade destas proteínas quando se busca uma aplicação mais abrangente das mesmas como ingredientes. Os resultados obtidos na primeira etapa deste estudo motivaram inicialmente o emprego da microfiltração na separação das correntes de amido e proteína do extrato alcalino, analisando a possibilidade de se obter um amido com elevada pureza e uma corrente de permeado contendo a proteína extraída. A análise global dos resultados obtidos nesse trabalho permite que seja destacado que a escolha da microfiltração para o processo de separação do amido e da proteína de arroz deve ser avaliada com cautela. Na quarta etapa deste estudo avaliou-se a aplicação da hidrólise enzimática parcial do concentrado proteico na solubilização da proteína de endosperma de arroz. A hidrólise parcial, realizada com Alcalase®, permitiu a solubilização de 40 % da proteína originalmente presente na suspensão de proteína extraída pelo método alcalino. Os peptídeos solúveis gerados apresentaram massa molar média de 1,18 ± 0,33 kDa, solubilidade proteica superior a 88,5 % na faixa de pH de 3 a 7 e boa capacidade de formação de espuma, apesar de formarem uma espuma de baixa estabilidade. Neste estudo o hidrolisado proteico foi concentrado e purificado por ultrafiltração, o que permitiu a redução de 68 % do conteúdo de sódio do produto. Concluiu-se que neste estudo foi possível propor um processo produtivo que permitiu a obtenção de ingredientes com adequadas propriedades nutricionais e funcionais a partir do coproduto arroz quebrado. / The Brazil is a large producer of food commodities, and today the development of the industry of ingredients to add value to these raw materials is an area little explored by the Brazilian industries. Rice stands out in the Brazilian agribusiness, as the country is the ninth largest producer. The broken rice is a byproduct derived from the processing of polished rice. This study aimed to propose and evaluate a process of obtaining rice protein concentrates and hydrolysates contributing to offer strategies for the technological development of the sector in Brazil. Additionally, it aims to assist in the valuation of the byproduct broken rice, a low commercial value food which is the basis for the generation of raw materials already found internationally, and which have great potential in the Brazilian market. Within this context, it sought to study the application of membrane technology in this process, because it is a clean, low-energy, well-established technology, with growing applications in the food industry. The study began with the evaluation of the effectiveness of a fast alkaline extraction method for obtaining rice starch and protein, using rice flour derived from broken rice as raw material, instead of broken grains, as in the traditional method. In this study, with the use of a substrate:solvent ratio of 1:15, the extraction step was performed in a single stage at 30 °C in 30 minutes - a short extraction time compared to traditional alkaline method (24-48h). The yield of protein extraction with these conditions was very high, reached 81.4%. It was possible to perform an efficient extraction, with the minimization of undesired reactions caused by the alkaline medium. In the second stage of this study were evaluated the functional properties of the protein concentrate obtained by the fast alkaline extraction method. In addition, their properties were compared with two commercial concentrated protein produced by enzymatic extraction. It was observed that all the evaluated protein concentrates showed poor functional properties, mainly due to their low solubility at pH conditions close to neutrality and slightly acidic, concluding that it is necessary studies aimed to improve the solubility of these proteins in order to seek more applications of this ingredient. The results obtained in the first step of this study initially motivated the use of microfiltration to separate the starch and protein chains of the alkali extract, analyzing the possibility of obtaining a starch with high purity and a permeate stream containing the extracted protein. The global analysis of the results obtained in this work allows it to be noted that the choice of microfiltration for the separation process of starch and rice protein should be evaluated with caution. In the fourth stage of this study was evaluated the application of the partial enzymatic hydrolysis in solubilization of rice endosperm protein. The partial hydrolysis performed with Alcalase allowed solubilization of 40% of the protein originally present in the protein suspension extracted by the alkaline method. The generated soluble peptides had molecular weight average of 1.18 ± 0.33 kDa, protein solubility higher than 88.5 % in the pH range 3 to 7, and good foaming ability, while forming a low stable foam. In this study, the protein hydrolyzate was concentrated and purified by ultrafiltration, allowing 68 % reduction in the sodium content of the product. It is concluded that in this study was proposed a production process allowing obtaining ingredients with suitable nutritional and functional properties from the byproduct broken rice.

陳瑤. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2011. / Includes bibliographical references (leaves 215-229) / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts in Chinese and English. / Chen Yao.

Two problems hampering efforts to produce salt-tolerant plants through constitutive expression of transgenes include: 1. Spatial control. Particular cell-types must respond specifically to salt stress to minimise the amount of Na⁺ delivered to the shoot; and, 2. Temporal control. Transgenes are typically expressed in plants at similar levels through time, irrespective of the stress encountered by the plant, which may exacerbate pleiotropic effects and means that, particularly in low-stress conditions, costly and/or detrimental metabolic processes may be active, thus reducing yield. To address these issues, Gateway® destination vector constructs were developed combining the GAL4 UAS (upstream activating sequence) with the ethanol-inducible gene expression system to drive inducible cell-specific expression of Na⁺ transporter transgenes (or to silence salt transporter transgenes inducibly and cell-specifically). Rice (Oryza sativa L. cv. Nipponbare) GAL4-GFP enhancer trap lines (Johnson et al., 2005: Plant J. 41, 779-789) that express GAL4 and GFP specifically in either the root epidermis or xylem parenchyma (and therefore ‘trap’ cell-type specific enhancer elements) were transformed with this GAL4 UAS – ethanol switch construct, thereby allowing both spatial and temporal control of transgenes. In preliminary experiments, the expression system successfully limited the expression of RFP to specific cell-types after induction with ethanol. Other genes expressed using this system include PpENA1, a Na⁺-extruding ATPase from the moss, Physcomitrella patens, and AtHKT1;1, a Na ⁺ transporter from Arabidopsis thaliana. The two enhancer trap rice lines were also transformed with the GAL4 UAS driving stable expression of AtHKT1;1 and PpENA1 specifically in root epidermal or xylem parenchyma cells. Expression of AtHKT1;1 in root epidermal cells reduced Na⁺ accumulation in the shoots, while expression in the root xylem parenchyma appeared to have little effect on shoot Na⁺ accumulation. Using cryo-scanning electron microscopy (SEM) X-ray microanalysis, the outer cells of the roots of the line expressing AtHKT1;1 in the epidermal cells were found to accumulate higher levels of Na⁺ than the parental enhancer trap line. Additionally, this line had decreased unidirectional ²²Na⁺ influx. Similar results were observed for plants expressing AtHKT1;1 driven by the CaMV 35S / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325289 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

Two problems hampering efforts to produce salt-tolerant plants through constitutive expression of transgenes include: 1. Spatial control. Particular cell-types must respond specifically to salt stress to minimise the amount of Na⁺ delivered to the shoot; and, 2. Temporal control. Transgenes are typically expressed in plants at similar levels through time, irrespective of the stress encountered by the plant, which may exacerbate pleiotropic effects and means that, particularly in low-stress conditions, costly and/or detrimental metabolic processes may be active, thus reducing yield. To address these issues, Gateway® destination vector constructs were developed combining the GAL4 UAS (upstream activating sequence) with the ethanol-inducible gene expression system to drive inducible cell-specific expression of Na⁺ transporter transgenes (or to silence salt transporter transgenes inducibly and cell-specifically). Rice (Oryza sativa L. cv. Nipponbare) GAL4-GFP enhancer trap lines (Johnson et al., 2005: Plant J. 41, 779-789) that express GAL4 and GFP specifically in either the root epidermis or xylem parenchyma (and therefore ‘trap’ cell-type specific enhancer elements) were transformed with this GAL4 UAS – ethanol switch construct, thereby allowing both spatial and temporal control of transgenes. In preliminary experiments, the expression system successfully limited the expression of RFP to specific cell-types after induction with ethanol. Other genes expressed using this system include PpENA1, a Na⁺-extruding ATPase from the moss, Physcomitrella patens, and AtHKT1;1, a Na ⁺ transporter from Arabidopsis thaliana. The two enhancer trap rice lines were also transformed with the GAL4 UAS driving stable expression of AtHKT1;1 and PpENA1 specifically in root epidermal or xylem parenchyma cells. Expression of AtHKT1;1 in root epidermal cells reduced Na⁺ accumulation in the shoots, while expression in the root xylem parenchyma appeared to have little effect on shoot Na⁺ accumulation. Using cryo-scanning electron microscopy (SEM) X-ray microanalysis, the outer cells of the roots of the line expressing AtHKT1;1 in the epidermal cells were found to accumulate higher levels of Na⁺ than the parental enhancer trap line. Additionally, this line had decreased unidirectional ²²Na⁺ influx. Similar results were observed for plants expressing AtHKT1;1 driven by the CaMV 35S / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325289 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

Two problems hampering efforts to produce salt-tolerant plants through constitutive expression of transgenes include: 1. Spatial control. Particular cell-types must respond specifically to salt stress to minimise the amount of Na⁺ delivered to the shoot; and, 2. Temporal control. Transgenes are typically expressed in plants at similar levels through time, irrespective of the stress encountered by the plant, which may exacerbate pleiotropic effects and means that, particularly in low-stress conditions, costly and/or detrimental metabolic processes may be active, thus reducing yield. To address these issues, Gateway® destination vector constructs were developed combining the GAL4 UAS (upstream activating sequence) with the ethanol-inducible gene expression system to drive inducible cell-specific expression of Na⁺ transporter transgenes (or to silence salt transporter transgenes inducibly and cell-specifically). Rice (Oryza sativa L. cv. Nipponbare) GAL4-GFP enhancer trap lines (Johnson et al., 2005: Plant J. 41, 779-789) that express GAL4 and GFP specifically in either the root epidermis or xylem parenchyma (and therefore ‘trap’ cell-type specific enhancer elements) were transformed with this GAL4 UAS – ethanol switch construct, thereby allowing both spatial and temporal control of transgenes. In preliminary experiments, the expression system successfully limited the expression of RFP to specific cell-types after induction with ethanol. Other genes expressed using this system include PpENA1, a Na⁺-extruding ATPase from the moss, Physcomitrella patens, and AtHKT1;1, a Na ⁺ transporter from Arabidopsis thaliana. The two enhancer trap rice lines were also transformed with the GAL4 UAS driving stable expression of AtHKT1;1 and PpENA1 specifically in root epidermal or xylem parenchyma cells. Expression of AtHKT1;1 in root epidermal cells reduced Na⁺ accumulation in the shoots, while expression in the root xylem parenchyma appeared to have little effect on shoot Na⁺ accumulation. Using cryo-scanning electron microscopy (SEM) X-ray microanalysis, the outer cells of the roots of the line expressing AtHKT1;1 in the epidermal cells were found to accumulate higher levels of Na⁺ than the parental enhancer trap line. Additionally, this line had decreased unidirectional ²²Na⁺ influx. Similar results were observed for plants expressing AtHKT1;1 driven by the CaMV 35S / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1325289 / Thesis (Ph.D.) -- University of Adelaide, School of Agriculture, Food and Wine, 2008

O Brasil é um grande produtor de commodities alimentícias, e hoje o desenvolvimento da indústria de ingredientes para a geração de insumos de maior valor agregado a partir destas matérias-primas é uma área pouco explorada pelas indústrias brasileiras. O arroz se destaca no agronegócio brasileiro, já que o país figura como o nono maior produtor mundial. O arroz quebrado é um coproduto do beneficiamento do arroz branco polido. Este estudo teve como objetivo propor e avaliar um processo de obtenção de concentrados e hidrolisados proteicos de arroz, contribuindo na oferta de estratégias para o desenvolvimento tecnológico do setor no Brasil. Adicionalmente, deseja-se auxiliar na valoração do coproduto arroz quebrado, alimento de baixo valor comercial, base para a geração de matérias-primas já encontradas internacionalmente, e que apresentam grande potencial de desenvolvimento no mercado brasileiro. Dentro deste contexto, buscou-se estudar a aplicação da tecnologia de membranas neste processo, por ser uma tecnologia limpa, de baixo consumo energético, já bem estabelecida e com aplicações crescentes na indústria de alimentos. O estudo iniciou com a avaliação da eficácia de um método rápido de extração alcalina de amido e proteína de arroz, no qual foi utilizada farinha de arroz derivada de arroz quebrado como matéria-prima, ao invés dos grãos quebrados, como no método tradicional. Nesse estudo, a partir do uso de uma razão substrato:solvente de 1:15, a etapa de extração foi realizada em estágio único a 30 oC em apenas 30 minutos – um curto tempo de extração se comparado ao método alcalino tradicional (24-48h). O rendimento da extração proteica com estas condições foi bastante elevado, atingiu 81,4 %. Observou-se ser possível realizar uma extração eficiente, com a minimização das reações indesejadas causadas pelo meio alcalino. Na segunda etapa foram avaliadas as propriedades funcionais do concentrado proteico obtido a partir do método rápido de extração alcalina. Além disso, suas propriedades foram comparadas com as de dois concentrados proteicos comerciais produzidos por extração enzimática. Foi observado que todos os concentrados proteicos avaliados apresentaram pobres propriedades funcionais, devido sobretudo a suas baixas solubilidades em condições de pH próximas à neutralidade e levemente ácidas, concluindo-se ser necessário estudos que visem a melhoria da solubilidade destas proteínas quando se busca uma aplicação mais abrangente das mesmas como ingredientes. Os resultados obtidos na primeira etapa deste estudo motivaram inicialmente o emprego da microfiltração na separação das correntes de amido e proteína do extrato alcalino, analisando a possibilidade de se obter um amido com elevada pureza e uma corrente de permeado contendo a proteína extraída. A análise global dos resultados obtidos nesse trabalho permite que seja destacado que a escolha da microfiltração para o processo de separação do amido e da proteína de arroz deve ser avaliada com cautela. Na quarta etapa deste estudo avaliou-se a aplicação da hidrólise enzimática parcial do concentrado proteico na solubilização da proteína de endosperma de arroz. A hidrólise parcial, realizada com Alcalase®, permitiu a solubilização de 40 % da proteína originalmente presente na suspensão de proteína extraída pelo método alcalino. Os peptídeos solúveis gerados apresentaram massa molar média de 1,18 ± 0,33 kDa, solubilidade proteica superior a 88,5 % na faixa de pH de 3 a 7 e boa capacidade de formação de espuma, apesar de formarem uma espuma de baixa estabilidade. Neste estudo o hidrolisado proteico foi concentrado e purificado por ultrafiltração, o que permitiu a redução de 68 % do conteúdo de sódio do produto. Concluiu-se que neste estudo foi possível propor um processo produtivo que permitiu a obtenção de ingredientes com adequadas propriedades nutricionais e funcionais a partir do coproduto arroz quebrado. / The Brazil is a large producer of food commodities, and today the development of the industry of ingredients to add value to these raw materials is an area little explored by the Brazilian industries. Rice stands out in the Brazilian agribusiness, as the country is the ninth largest producer. The broken rice is a byproduct derived from the processing of polished rice. This study aimed to propose and evaluate a process of obtaining rice protein concentrates and hydrolysates contributing to offer strategies for the technological development of the sector in Brazil. Additionally, it aims to assist in the valuation of the byproduct broken rice, a low commercial value food which is the basis for the generation of raw materials already found internationally, and which have great potential in the Brazilian market. Within this context, it sought to study the application of membrane technology in this process, because it is a clean, low-energy, well-established technology, with growing applications in the food industry. The study began with the evaluation of the effectiveness of a fast alkaline extraction method for obtaining rice starch and protein, using rice flour derived from broken rice as raw material, instead of broken grains, as in the traditional method. In this study, with the use of a substrate:solvent ratio of 1:15, the extraction step was performed in a single stage at 30 °C in 30 minutes - a short extraction time compared to traditional alkaline method (24-48h). The yield of protein extraction with these conditions was very high, reached 81.4%. It was possible to perform an efficient extraction, with the minimization of undesired reactions caused by the alkaline medium. In the second stage of this study were evaluated the functional properties of the protein concentrate obtained by the fast alkaline extraction method. In addition, their properties were compared with two commercial concentrated protein produced by enzymatic extraction. It was observed that all the evaluated protein concentrates showed poor functional properties, mainly due to their low solubility at pH conditions close to neutrality and slightly acidic, concluding that it is necessary studies aimed to improve the solubility of these proteins in order to seek more applications of this ingredient. The results obtained in the first step of this study initially motivated the use of microfiltration to separate the starch and protein chains of the alkali extract, analyzing the possibility of obtaining a starch with high purity and a permeate stream containing the extracted protein. The global analysis of the results obtained in this work allows it to be noted that the choice of microfiltration for the separation process of starch and rice protein should be evaluated with caution. In the fourth stage of this study was evaluated the application of the partial enzymatic hydrolysis in solubilization of rice endosperm protein. The partial hydrolysis performed with Alcalase allowed solubilization of 40% of the protein originally present in the protein suspension extracted by the alkaline method. The generated soluble peptides had molecular weight average of 1.18 ± 0.33 kDa, protein solubility higher than 88.5 % in the pH range 3 to 7, and good foaming ability, while forming a low stable foam. In this study, the protein hydrolyzate was concentrated and purified by ultrafiltration, allowing 68 % reduction in the sodium content of the product. It is concluded that in this study was proposed a production process allowing obtaining ingredients with suitable nutritional and functional properties from the byproduct broken rice.

O Brasil é um grande produtor de commodities alimentícias, e hoje o desenvolvimento da indústria de ingredientes para a geração de insumos de maior valor agregado a partir destas matérias-primas é uma área pouco explorada pelas indústrias brasileiras. O arroz se destaca no agronegócio brasileiro, já que o país figura como o nono maior produtor mundial. O arroz quebrado é um coproduto do beneficiamento do arroz branco polido. Este estudo teve como objetivo propor e avaliar um processo de obtenção de concentrados e hidrolisados proteicos de arroz, contribuindo na oferta de estratégias para o desenvolvimento tecnológico do setor no Brasil. Adicionalmente, deseja-se auxiliar na valoração do coproduto arroz quebrado, alimento de baixo valor comercial, base para a geração de matérias-primas já encontradas internacionalmente, e que apresentam grande potencial de desenvolvimento no mercado brasileiro. Dentro deste contexto, buscou-se estudar a aplicação da tecnologia de membranas neste processo, por ser uma tecnologia limpa, de baixo consumo energético, já bem estabelecida e com aplicações crescentes na indústria de alimentos. O estudo iniciou com a avaliação da eficácia de um método rápido de extração alcalina de amido e proteína de arroz, no qual foi utilizada farinha de arroz derivada de arroz quebrado como matéria-prima, ao invés dos grãos quebrados, como no método tradicional. Nesse estudo, a partir do uso de uma razão substrato:solvente de 1:15, a etapa de extração foi realizada em estágio único a 30 oC em apenas 30 minutos – um curto tempo de extração se comparado ao método alcalino tradicional (24-48h). O rendimento da extração proteica com estas condições foi bastante elevado, atingiu 81,4 %. Observou-se ser possível realizar uma extração eficiente, com a minimização das reações indesejadas causadas pelo meio alcalino. Na segunda etapa foram avaliadas as propriedades funcionais do concentrado proteico obtido a partir do método rápido de extração alcalina. Além disso, suas propriedades foram comparadas com as de dois concentrados proteicos comerciais produzidos por extração enzimática. Foi observado que todos os concentrados proteicos avaliados apresentaram pobres propriedades funcionais, devido sobretudo a suas baixas solubilidades em condições de pH próximas à neutralidade e levemente ácidas, concluindo-se ser necessário estudos que visem a melhoria da solubilidade destas proteínas quando se busca uma aplicação mais abrangente das mesmas como ingredientes. Os resultados obtidos na primeira etapa deste estudo motivaram inicialmente o emprego da microfiltração na separação das correntes de amido e proteína do extrato alcalino, analisando a possibilidade de se obter um amido com elevada pureza e uma corrente de permeado contendo a proteína extraída. A análise global dos resultados obtidos nesse trabalho permite que seja destacado que a escolha da microfiltração para o processo de separação do amido e da proteína de arroz deve ser avaliada com cautela. Na quarta etapa deste estudo avaliou-se a aplicação da hidrólise enzimática parcial do concentrado proteico na solubilização da proteína de endosperma de arroz. A hidrólise parcial, realizada com Alcalase®, permitiu a solubilização de 40 % da proteína originalmente presente na suspensão de proteína extraída pelo método alcalino. Os peptídeos solúveis gerados apresentaram massa molar média de 1,18 ± 0,33 kDa, solubilidade proteica superior a 88,5 % na faixa de pH de 3 a 7 e boa capacidade de formação de espuma, apesar de formarem uma espuma de baixa estabilidade. Neste estudo o hidrolisado proteico foi concentrado e purificado por ultrafiltração, o que permitiu a redução de 68 % do conteúdo de sódio do produto. Concluiu-se que neste estudo foi possível propor um processo produtivo que permitiu a obtenção de ingredientes com adequadas propriedades nutricionais e funcionais a partir do coproduto arroz quebrado. / The Brazil is a large producer of food commodities, and today the development of the industry of ingredients to add value to these raw materials is an area little explored by the Brazilian industries. Rice stands out in the Brazilian agribusiness, as the country is the ninth largest producer. The broken rice is a byproduct derived from the processing of polished rice. This study aimed to propose and evaluate a process of obtaining rice protein concentrates and hydrolysates contributing to offer strategies for the technological development of the sector in Brazil. Additionally, it aims to assist in the valuation of the byproduct broken rice, a low commercial value food which is the basis for the generation of raw materials already found internationally, and which have great potential in the Brazilian market. Within this context, it sought to study the application of membrane technology in this process, because it is a clean, low-energy, well-established technology, with growing applications in the food industry. The study began with the evaluation of the effectiveness of a fast alkaline extraction method for obtaining rice starch and protein, using rice flour derived from broken rice as raw material, instead of broken grains, as in the traditional method. In this study, with the use of a substrate:solvent ratio of 1:15, the extraction step was performed in a single stage at 30 °C in 30 minutes - a short extraction time compared to traditional alkaline method (24-48h). The yield of protein extraction with these conditions was very high, reached 81.4%. It was possible to perform an efficient extraction, with the minimization of undesired reactions caused by the alkaline medium. In the second stage of this study were evaluated the functional properties of the protein concentrate obtained by the fast alkaline extraction method. In addition, their properties were compared with two commercial concentrated protein produced by enzymatic extraction. It was observed that all the evaluated protein concentrates showed poor functional properties, mainly due to their low solubility at pH conditions close to neutrality and slightly acidic, concluding that it is necessary studies aimed to improve the solubility of these proteins in order to seek more applications of this ingredient. The results obtained in the first step of this study initially motivated the use of microfiltration to separate the starch and protein chains of the alkali extract, analyzing the possibility of obtaining a starch with high purity and a permeate stream containing the extracted protein. The global analysis of the results obtained in this work allows it to be noted that the choice of microfiltration for the separation process of starch and rice protein should be evaluated with caution. In the fourth stage of this study was evaluated the application of the partial enzymatic hydrolysis in solubilization of rice endosperm protein. The partial hydrolysis performed with Alcalase allowed solubilization of 40% of the protein originally present in the protein suspension extracted by the alkaline method. The generated soluble peptides had molecular weight average of 1.18 ± 0.33 kDa, protein solubility higher than 88.5 % in the pH range 3 to 7, and good foaming ability, while forming a low stable foam. In this study, the protein hydrolyzate was concentrated and purified by ultrafiltration, allowing 68 % reduction in the sodium content of the product. It is concluded that in this study was proposed a production process allowing obtaining ingredients with suitable nutritional and functional properties from the byproduct broken rice.

Conselho Nacional de Desenvolvimento Científico e Tecnológico / Human activity has been pointed out as the main reason of global warming by effluxes of CO2, N2O and CH4. In the last years, harmful effects of greenhouse gases due to its increase in atmosphere have been arousing interests of scientists into propose mechanisms of mitigation. Flooding rice is responsible for about 12% of CH4 released to atmosphere and therefore, is considerate one of the most important source of this greenhouse gas. There are many factors that control CH4 efflux in irrigated rice fields, which difficult an accurate identification of the responsible mechanisms. However, is known that irrigation regime and selection of rice cultivars affect CH4 efflux and may be managed intending to mitigate it. The objectives of this thesis were: (a) verify the effect of continuous irrigation, intermittent irrigation and intermittent flooding into CH4 efflux of a hapludalf soil cultivated with flooding rice at central region of Rio Grande do Sul State; (b) evaluate CH4 efflux of rice cultivated in greenhouse under different irrigation managements and relate the efflux to agronomic parameters of rice plants; (c) evaluate the irrigation systems over the rice crop and how it affect the electrochemical of soil solution and plant development; (d) evaluate CH4 efflux through cultivars of rice from Rio Grande do Sul and Santa Catarina States and relate it to plant morphological attributes. Intermittent irrigation was efficient to mitigate CH4 efflux in rice cultivations, when the lack of rain did not establish water layers, without having decrease in rice productivity. intermittent flooding management by irrigations, even at saturated soil, decreased the CH4 efflux by 70%. The management of intermittent flooding by irrigations when soil was bellow the field capacity do not cause CH4 efflux, however, this management caused decrease of rice productivity. Irrigation management does affect electrochemical conditions of soil, which are determinant to the CH4 production in soils. The dynamic of efflux of CH4 is similar between cultivars; however, there are differences on potential of CH4 efflux from cultivars of flooding rice. The cultivars Arize 1003, Avaxi Cl, BRS Atalanta, BRS Querência, BRS Taim, Inov Cl, Irga 422 and Irga 424 have showed lower efflux and higher productivities. Morphological characteristics of plants have not explained completely the differences of CH4 effluxes between cultivars. / A atividade antrópica tem sido apontada como a principal causa do aquecimento global pelo efluxo de CO2, N2O e CH4. Nos últimos anos, os efeitos prejudiciais do aumento da concentração atmosférica desses gases têm despertado os cientistas a propor mecanismos de mitigação. A cultura do arroz irrigado por alagamento é responsável por cerca de 12% do efluxo total de CH4 para a atmosfera, sendo considerada uma das principais fontes emissoras desse gás de efeito estufa. Os fatores que controlam o efluxo de CH4 no arroz irrigado são muitos, dificultando identificar com precisão os mecanismos responsáveis pelo seu efluxo. O regime de irrigação e a seleção de cultivares de arroz são fatores que afetam o efluxo de CH4 e podem ser modificados visando mitigar os efluxos para a atmosfera. Os objetivos da tese foram: (a) verificar o efeito do regime de irrigação contínua, intermitente e a banhos no efluxo de CH4 em um Planossolo cultivado com arroz irrigado por alagamento na Depressão Central do Rio Grande do Sul; (b) avaliar o efluxo de CH4 no arroz cultivado em casa de vegetação submetido a diferentes manejos de irrigação e relacionar o efluxo com parâmetros agronômicos da planta de arroz; (c) avaliar os sistemas de manejo de irrigação na cultura do arroz e os efeitos nos atributos eletroquímicos da solução do solo e no desenvolvimento das plantas; (d) avaliar o efluxo de CH4 em cultivares de arroz do RS e SC e relacionar com atributos morfofisiológicos das cultivares; e (e) caracterizar morfologicamente a cultura do arroz e verificar a provável rota de difusão do CH4 do solo até a atmosfera. A prática da irrigação intermitente foi eficiente em mitigar o efluxo de CH4 no cultivo do arroz irrigado quando as condições climáticas permitiram a ausência da lâmina de água durante o cultivo, sem diminuir a produtividade do arroz. O manejo da irrigação intermitente com o realagamento do solo ainda saturado diminuiu a emissão de CH4 em 70%. O manejo intermitente da irrigação com o realagamento do solo abaixo da capacidade de campo não causa efluxo de CH4, porém os efeitos foram negativos sobre a produtividade do arroz. O manejo da irrigação afeta as condições eletroquímicas do solo e são determinantes para a produção de CH4 nos solos. A dinâmica de efluxo de CH4 é semelhante entre as cultivares, porém, existem diferenças no potencial de efluxo de CH4 em cultivares de arroz irrigado por alagamento. As cultivares Arize 1003, Avaxi Cl, BRS Atalanta, BRS Querência, BRS Taim, Inov Cl, Irga 422 e Irga 424 apresentaram menor efluxo de CH4 com a maior produtividade do arroz. As características morfofisiológicas das plantas não explicaram completamente as diferenças de efluxos de CH4 entre as cultivares.