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During drying and freezing, protective mechanisms act to maintain seed physiological quality. Some of these mechanisms contribute to the integrity of cell membranes. The damage caused to cell membranes due to cell stress can be seen in ultrastructural studies. The aim of this study was to investigate ultrastructural changes in endosperm cells of coffee seeds brought about by drying and by exposure to low temperatures. Seeds of Coffea arabica were dried in silica gel to moisture contents of 40, 20, and 5 % (wb) and brought to equilibrium at temperatures of 10, -20, and -86oC. Germination, vigor, and tetrazolium tests were performed for evaluation of seed physiological quality. Ultrastructural damage was analyzed by scanning electron microscopy. Coffee seeds with 40% moisture content have whole, swollen, and expanded cells, with a filled lumen and without signs of damage. The physiological and ultrastructural quality of seeds exposed to below zero temperatures with 40% moisture content is compromised. They have null germination and empty cells, indicating leakage of cell content. Drying of coffee seeds leads to uniform contraction of inner cell content. Drying of coffee seeds to 5% moisture content leads to intense contraction of cell volume, with physiological and ultrastructural damage. Key words: Scanning electron microscopy; desiccation tolerance; Coffea arabica L.

In tomatoes production system, etiolation is the main cause of seedlings loss. Some inhibitors, such as paclobutrazol (PBZ), have been used to reduce this problem. This study aimed to evaluate the effect of different doses of paclobutrazol, with and without polymer association, at different degrees of permeability, on the physiological quality of seeds. Seeds of two tomato cultivars, Ozone and Paronset, were treated with four concentrations of paclobutrazol (0, 0.004, 0.008 and 0.016 g mL a.i.10 g seeds-1), and combined with three fixatives (water, P1 and P2). After the treatments, germination test, germination speed index test and cold test were carried out, and after five months of seed storage, the analyzes were repeated. The increase in PBZ dose reduces both germination percentage and germination speed index. After storage, the product acts differently on seed germination. The synthetic polymers, in the dose used in this study, are effective in PBZ fixation on the seeds coat, but do not reduce the harmful effect of PBZ on seed germination.

Preservation of the quality of coffee seeds is hindered by their intermediate behavior in storage. However, long-term storage at sub zero temperatures may be achieved by adjusting the water content of the seeds. The aim of this study was to evaluate the tolerance of coffee seeds to freezing, in relation to physiological and enzymatic modifications. Coffee seeds were dried in two manners, rapid and slow, to water contents of interest, 0.67, 0.43, 0.25, 0.18, 0.11, and 0.05 g H2O g-¹ dw (dry basis). After drying, the seeds were stored at a temperature of -20 ºC and of 86 ºC for 24 hours and for 12 months, and then compared to seeds in cold storage at 10 ºC. The seeds were evaluated through calculation of percentage of normal seedlings, percentage of seedlings with expanded cotyledonary leaves, dry matter of roots and of hypocotyls, and viability of embryos in the tetrazolium test. Expression of the enzymes superoxide dismutase, catalase, and peroxidase were evaluated by means of electrophoretic analysis. Only seeds dried more slowly to 0.18 g H2O g-1 dw present relative tolerance to storing at -20 °C for 12 months. Coffee seeds do not tolerate storage at a temperature of -86 ºC for 12 months. Water contents below 0.11g H2O g-¹ dw and above 0.43 g H2O g-¹ dw hurt the physiological quality of coffee seeds, regardless of the type of drying, temperature, and storage period. Coffee seed embryos are more tolerant to desiccation and to freezing compared to whole seeds, especially when the seeds are dried to 0.05 g H2O g-¹ dw. The catalase enzyme can be used as a biochemical marker to study tolerance to freezing in coffee seeds. RESUMO A preservação da qualidade de sementes de café é dificultada pelo comportamento intermediário no armazenamento. Porém, a conservação a longo prazo em temperaturas subzero pode ser conseguido com o ajuste do teor de água das sementes. Objetivou-se neste trabalho avaliar a tolerância de sementes de café ao congelamento, com relação às modificações fisiológicas e enzimáticas. As sementes foram submetidas a dois tipos de secagem, rápida e lenta, até os teores de água de interesse, de 0,67, 0,43, 0,25, 0,18, 0,11, 0,05 g H2O g-¹ dw (base seca). Após secagem, as sementes foram armazenadas em temperatura de -20 e de -86 ºC, por 24 horas e por 12 meses, sendo comparadas às sementes armazenadas em câmara fria a 10 ºC. As sementes foram avaliadas pela porcentagem de plântulas normais, plântulas com folhas cotiledonares expandidas, matéria seca de raízes e de hipocótilos e viabilidade dos embriões no teste de tetrazólio. A expressão das enzimas superóxido dismutase, catalase e peroxidase foi avaliada por meio de análise eletroforética. Apenas as sementes secadas lentamente até 0,18 g H2O g-¹ dw apresentam relativa tolerância ao armazenamento a -20 °C por 12 meses. Sementes de café não toleram o armazenamento à temperatura de -86 ºC por 12 meses. Umidades abaixo de 0,11g H2O g-¹ dw e acima de 0,43 g H2O g-¹ dw são prejudiciais à qualidade fisiológica das sementes de café, independentemente do tipo de secagem, temperatura e período de armazenamento. Embriões de sementes de café são mais tolerantes à dessecação e ao congelamento quando comparado às sementes inteiras, principalmente quando as sementes são secadas até 0,05 g H2O g-¹ dw. A enzima catalase pode ser usada como um marcador bioquímico para estudar a tolerância de sementes de café ao congelamento.

The endo-β-mannanase acts on the hemicellulose fraction of the endosperm cell walls, mainly mannans and galactomannans. This process weakens cell walls and allows radicle protrusion during seed germination, but may also occur during the deterioration process. Thus, the aim of this research was to determine the activity of endo-β-mannanase enzyme in dry coffee seeds and in soaked seeds, evaluating its relationship between physiological qualities. Coffee seeds obtained by different processing methods (natural, fermented and demucilated) and drying (sun, shade and dryer) were used. Seed quality was evaluated by germination and tetrazolium tests, and the endo-β-mannanase enzyme activity was determined in dry seeds and after 10 days of soaking. From the results, it was concluded that there is significant inverse relationship between the physiological quality of coffee seeds and the expression of endo-β-mannanase, and seeds with lower percentages of germination and viability of embryos have a higher activity of the enzyme. After ten days of soaking, coffee seeds had higher expression of endo-β-mannanase as compared to the dry seeds for all treatments of fruit processing and drying. Key words: Coffea arabica L., processing, drying, physiological quality.

Selenium is essential to human and animal health, as it regulates glutathione peroxidase activity. Although not considered essential to plants, it may be beneficial to plant growth and development at low concentrations. This study evaluated the effect of selenate application on Se biofortification, macro- and micronutrient content, and the expression of genes involved in Se uptake and assimilation in 12 Brazilian wheat ( L.) cultivars. This nutrient-solution experiment was performed in a greenhouse and consisted of a complete 12 × 2 factorial randomized design, with 12 wheat cultivars in the absence or presence of Se in solution (13 μmol), with three replicates. The presence of Se in solution did not affect growth and yield of wheat cultivars. Selenium content and accumulation in the grain varied significantly among the different cultivars. The presence of Se affected macronutrient content more than micronutrient content, and selenate application increased S content in the shoots of eight cultivars and in the grains of five cultivars. Examination of gene expression did not allow identification of responses within the two groups of cultivars-with high or low Se contents-after selenate application. Our findings are relevant to the design of Se biofortification strategies for wheat in tropical and subtropical agroecosystems.

Coffea canephora ‘Apoatã’ seeds are used for the formation of rootstocks for grafting of C. arabica seedlings. The quality of seeds and the individualization of used genotypes are prevalent factors for the formation of vigorous rootstocks that will enhance the formation of quality seedlings. The aim of the present study was to characterize and evaluate the seed quality of C. canephora ‘Apoatã’ genotypes for potential use of rootstocks for C. arabica species. Were used seeds of 30 C. canephora ‘Apoatã’ genotypes, obtained from the experimental field of Embrapa Rondônia in Ouro Preto do Oeste, RO, Brazil. The seeds were processed and subjected to germination, first germination count and tetrazolium tests. Moisture, 100- seed mass and chemical composition analyses of seeds were also determined. The mass, physiological quality and chemical composition of C. canephora ‘Apoatã’ seeds vary according to the genotype. The variation of the physiological quality of C. canephora ‘Apoatã’ seeds is not related individually to caffeine, total sugars, ash, ether extract, crude fiber protein and chlorogenic acid. Seed batches of C. canephora ‘Apoatã’ from different genotypes contain seeds of different sizes, being indicated the classification before the processing stage in order to prevent mechanical damages.

O objetivo deste trabalho foi avaliar alterações fisiológicas e bioquímicas em sementes de café submetidas à secagem rápida, em sílica gel, e à secagem lenta, em soluções salinas saturadas. As sementes foram secas até que atingissem os seguintes teores de água: 40, 30, 20, 15, 10 e 5% (base úmida). Após a secagem, uma parte das sementes foi imediatamente avaliada quanto ao desempenho fisiológico e ao perfil de enzimas do processo oxidativo, e outra parte foi avaliada após armazenagem em condição hermética, em câmara fria e seca, por quatro meses. A velocidade de secagem e o teor final de água tiveram efeito significativo sobre a qualidade fisiológica das sementes. Após a secagem rápida em sílica gel, as sementes toleraram teores finais de água mais baixos. No entanto, após a secagem lenta, as sementes com teores finais de água mais elevados apresentaram maior qualidade. O período de armazenamento não afetou a germinação, mas prejudicou o vigor das sementes. A secagem rápida apresenta maior potencial de dano ao endosperma do que aos embriões. O perfil enzimático das sementes de café é afetado pelo teor final de água e pela velocidade de secagem. The objective of this work was to evaluate the physiological and biochemical changes in coffee seed subjected to rapid drying, in silica gel, or to slow drying in saturated saline solutions. Seeds were dried until they reached the following water contents: 40, 30, 20, 15, 10, and 5% (wet basis). After drying, part of the seeds was immediately evaluated as to their physiological performance and enzymatic profile of the oxidative process, and another part was evaluated after storage, under hermetic conditions, in freeze-drying chamber, for four months. Drying rate and final moisture content had significant effect on seed physiological quality. After rapid drying, in silica gel, seeds tolerated lower final moisture levels. However, after slow drying, seeds with greater water levels showed higher quality. The storage period did not affect germination, but it reduced coffee seed vigor. Rapid drying shows greater damage potential to the endosperm than to the embryos. The enzymatic profile of coffee seed is affected by the final moisture level and the drying rate.

The objective of the study was to use methodology of simultaneous optimization of multiple responses applied to an experimental design to determine the best combination of storage period and conditions for preservation of coffee beans. Coffea arabica L. fruits were harvested in the ripe stage of maturation, processed using wet and dry methods, and dried to 11% (wet basis) moisture content. Part of the beans was hulled, while the other part was hulled only after the beans were stored under two different environmental conditions: cooled air at 10 ºC with 50% relative humidity; and at 25 ºC without controlling the relative humidity. Samples were taken at 3, 6, and 12 months intervals in order to evaluate quality. The data were submitted to the simultaneous optimization of responses for each processing and hulling condition separately, in a completely randomized design and 2 x 3 factorial scheme (two storage conditions and three storage periods). In conclusion, the use of the simultaneous optimization of responses is viable to be applied for determining the ideal storage conditions in a refrigerated condition. RESUMO Objetivou-se utilizar a metodologia de resposta simultânea aplicada a um delineamento experimental para determinar a melhor combinação de tempo e das condições de armazenamento para a conservação de grãos de café. Frutos de Coffea arabica L. foram colhidos no estádio de maturação cereja, processados por via úmida ou por via seca e secados até atingir 11% de teor de água. Parte dos grãos foi beneficiada e parte não foi beneficiada antes de ser armazenada em duas condições de ambiente: em ar refrigerado a 10 ºC e umidade relativa de 50% e em 25 ºC sem controle da umidade relativa do ar. Nos períodos de 3, 6 e 12 meses, foram retiradas amostras para avaliação da qualidade. Os dados foram submetidos à técnica de otimização de resposta simultânea para cada processamento e beneficiamento separadamente, em delineamento inteiramente casualizado e esquema fatorial 2 x 3 (duas condições de armazenamento e três períodos de armazenamento). Conclui-se que a utilização da metodologia de resposta simultânea é viável para ser aplicada para determinação das condições ideais de armazenamento em condição refrigerada.

The pathogenic fungi may be associated with the seeds during development, harvest and storage, and it can be disseminated through them. This work evaluated the seeds performance of three hybrid corn cultivars, BM 840 PRO, BM 810 and BM 207, submitted to different inoculum potentials of Fusarium verticillioides . Seeds were uniformly distributed over the medium fungal colony developed on PDA (potato dextrose agar) containing mannitol in water potential -2.0 MPa. Seeds remained in this way for different periods of contamination (0, 24, 48, 72 and 96 hours). Before and after seven months of seed storage the evaluations were performed. Seeds treated with fungicide Derosal Plus® (carbendazim + thiram, 250 mL p.c. 100 kg -1 ofseeds) were used as control. The increased of inoculum potential of F. verticillioides fungus on corn seeds caused reduction in physiological quality in the potentials 72 and 96 hours of exposure before and after storage. The highest Fusarium verticillioides incidence is observed in non-stored seeds. Fusarium verticillioides incidence on corn seeds accentuates the deterioration in storage.

Germination of coffee seeds occurs in a slow and non-uniform manner and the tetrazolium test (TZ) may be a quick alternative for assessment of viability, as long as the preparation and imbibition of the seeds is established. This study was performed in two stages: in the first, recently harvested seeds from three coffee cultivars were submitted to four methodologies for removal of the parchment: manual extraction or use of sodium hypochlorite (NaClO at 5%) and two periods of imbibition of the seeds in water (36 and 48 hours) for removal of the embryos. In the second phase, manual removal and the use of NaClO were compared for elimination of the parchment of stored seeds for monthly performance of the tetrazolium test for six months. Sodium hypochlorite is not efficient in total extraction of the parchment and has a negative effect on the results of the TZ test on low moisture coffee seeds. An imbibition time of 48 hours facilitates extraction of embryos and does not affect test results. The tetrazolium test on coffee seeds with different moisture and deterioration levels must be undertaken with manual removal of the parchments.

O teste de tetrazólio (TZ) é uma alternativa para avaliação rápida da viabilidade de sementes já adotada para a comercialização de sementes de café. Um dos entraves para a utilização do teste é a dificuldade na extração do endocarpo que demanda tempo e mão de obra especializada. A utilização de hipoclorito de sódio é recomendada para extração do endocarpo de sementes de café para acelerar o processo de germinação, no entanto essa metodologia ainda não foi testada na realização do teste de tetrazólio. Sementes de café de quatro lotes de duas cultivares foram submetidas a quatro metodologias para a realização do teste: extração manual ou utilização de hipoclorito de sódio (200 mL de NaClO a 5%) para remoção do pergaminho e períodos de embebição das sementes em água (36 e 48 horas) para a retirada dos embriões. Os resultados de viabilidade pelo TZ foram comparados com os de germinação das sementes com diferentes teores de água. O uso do NaClO na concentração de 5% por 6 horas de embebição não é eficiente para a retirada do pergaminho e afeta negativamente os resultados do TZ em semente de café com teor de água abaixo de 25%. O período de embebição de sementes de café em água por 48 horas na fase de preparo, para a realização do TZ, facilita a extração dos embriões, não afetando os resultados do teste. The tetrazolium test (TZ) is a rapid alternative for evaluating seed viability and has been adopted for the commercialization of coffee seeds. One of the barriers to using this test is the difficulty of extracting the parchment, which requires time and specialized labor. The use of sodium hypochlorite has been recommended for parchment extraction in coffee seeds but this method has not been tested for the TZ. Coffee seeds of four lots of two varieties were submitted to four methods in the test: manual extraction or use of sodium hypochlorite (200 mL 5% NaClO) to remove the parchment and various periods for soaking seeds in water (36 to 48 hours), to remove the embryos. The results of the viability from the TZ were compared with those from the germination of seeds with different moisture contents. The use of 5% NaClO with 6 hours of soaking is not effective in removing the parchment and adversely affects the results of the TZ in coffee seeds with a moisture content below 25%. The imbibition period of coffee seeds in water for 48 hours in the preparation phase for the TZ, facilitates embryo extraction without affecting the test results.

Coffee seeds begin to develop shortly after fertilization and can take 6 to 8 months to complete their formation, a period during which all the characteristics of the mature seed are determined, directly influencing physiological quality. However, little is known about the molecular mechanisms that act during coffee seed maturation. The objective of the current study was to analyze expression of the β-tubulin (TUB) and endo-β-mannanase (MAN) genes during different phases at the end of development and in different tissues of Coffea arabica seeds. The transcription levels of the TUB and MAN genes were quantified in a relative manner using qRT-PCR in whole seeds, and dissected into embryos and endosperms at different developmental stages. Greater expression of MAN was observed in whole seeds and in endosperms during the green stage, and in the embryo during the over-ripe stage. High TUB gene expression was observed in whole seeds during the green stage and, in the embryos, there were peaks in expression during the over-ripe stage. In endosperms, the peak of expression occurred in both the green stage and in the cherry stage. These results suggest participation of endo-β-mannanase during the initial seed developmental stages, and in the stages of physiological maturity in the embryo tissues. TUB gene expression varied depending on the developmental stage and section of seed analyzed, indicating the participation of β-tubulin during organogenesis and coffee seed maturation.

Seed germination and dormancy are complex phenomena that are controlled by many genes and environmental factors. Such genes are indicated by phytohormones that interact with each other, and may cause dormancy or promote seed germination. The objective of this study was to investigate gene expression associated with the biosynthetic pathways of abscisic acid (ABA), gibberellic acid (GA), and ethylene (ET) in dormant and germinated lettuce seeds. The expressions of LsNCED, LsGA3ox1, and ACO-B were evaluated in germinating and dormant seeds from the cultivars Everglades, Baba de Verao, Veronica, Salinas, Colorado, and Regina 71. The expressions of LsNCED, LsGA3ox1, and ACO-B were related to the biosynthesis of ABA, GA, and ET, respectively; therefore, the presence of these substances depends on genotype. LsNCED expression only occurred in dormant seeds, and was connected to dormancy. LsGA3ox1expression only occurred in germinated seeds, and was connected to germination. The ACO-B gene was involved in ET biosynthesis, and was expressed differently in germinated and dormant seeds, depending on the genotype, indicating different functions for different characteristics. Furthermore, sensitivity to phytohormones appeared to be more important than the expression levels of LsNCED, LsGA3ox1, or ACO-B.

In recent research, early stages of coffee seedling development were identified, after radicle protrusion, in which all the essential parts of the seedling can be assessed to demonstrate the potential of seed germination to generate normal plants. Thus, the objective of this research was to develop studies to reduce the time on the germination test. Ten seed lots of coffee were assessed through the germination test, every two days, from the tenth day of sowing, according to the morphological criteria of the seedlings. The data were compared to the standard germination test and analyzed by means of regression analysis and segmented nonlinear regression and planteau response model. It was concluded that the assessment of coffee seedlings at 16 days, in stage S1, provides the similar result of the pattern germination test, allowing a significant reduction of time in order to demonstrate the germination of the seed lots; the seedling assessment coffee in stage S2 does not have reduction of the time for assessing the coffee germination, in relation to the pattern. Em pesquisas recentes, estádios precoces do desenvolvimento das plântulas de café foram identificados após a protrusão da radícula, em que todas as partes essenciais da plântula podem ser avaliadas, e assim atestam o potencial das sementes em gerar plantas normais. Desta forma, o objetivo nesta pesquisa foi desenvolver estudos para reduzir o período do teste de germinação de sementes de café. Dez lotes de sementes de café foram avaliados por meio do teste de germinação, a cada dois dias, a partir do décimo dia da semeadura, segundo os critérios morfológicos das plântulas. Os dados foram comparados aos do teste padrão de germinação e analisados por meio de análises de regressão não linear segmentada e modelo de resposta em platô. Concluiu-se que a avaliação de plântulas de café aos 16 dias, no estádio S1, proporciona resultados similares ao teste padrão, permitindo redução significativa do período para atestar a germinação de um lote de sementes; a avaliação das plântulas no estádio S2 não permite redução do período de avaliação da germinação de sementes de café em relação ao teste padrão.

Objetivando avaliar as alterações que ocorrem durante o período de dormência das sementes de arroz irrigado, conduziram-se três experimentos sob diferentes condições de armazenamento. Sementes da cultivar Rio Grande, com alta intensidade de dormência pós-colheita, foram acondicionadas em sacos de papel multifoliado e armazenadas por um período de 12 meses, em câmara fria e seca (10ºC e 50% de umidade relativa) em armazém convencional em três localidades. Trimestralmente foram feitas avaliações por meio do teor de água, teste de germinação, alterações nos perfis eletroforéticos das isoenzimas Polifenoloxidase (PPO), Peroxidase (PO), Alfa-amilase (alfa-AM) e Beta-amilase (beta-AM) em gel de acrilamida e, de grupos redutores pela espectrofotometria. O tempo e as condições de armazenamento influenciam na superação da dormência das sementes, sendo que, em ambiente de armazém convencional, sementes de arroz superam a dormência em períodos de tempos menores que as sementes armazenadas em câmara fria e seca. As mudanças na atividade das enzimas alfa-AM e P.P.O. possuem relação direta com as alterações na porcentagem de germinação, pois, enquanto a atividade da alfa-AM aumenta a da P.P.O. diminui à medida que a dormência é superada, sugerindo ser a atividade dessas enzimas um promissor indicador da intensidade de dormência das sementes de arroz. Entretanto, a atividade das enzimas P.O. e beta-AM não se correlacionam com a dormência em sementes de arroz. Aiming to evaluate the alterations that occur during the dormancy period of irrigated rice seeds, three experiments were carried out at different storage conditions. Seeds from Rio Grande cultivar, highly post-harvest dormant seeds, after preparation, were placed in multilayered paper bags and stored for 12 months, in a cold and dry (10ºC and 50% of relative humidity) and in three conventional storage. Every three months, water content, germination, alterations in the electrophoretical profile of the isoenzymes Polyphenoloxidase (PPO), Peroxidase (PO), Alpha-amylase (alpha-AM), Beta-amylase (beta-amylase) in polyacrilamide gel and reducing groups by spectrophotometer were evaluated. Storage conditions and duration have influenced the dormancy breakage, and, in the conventional storage environment, rice seeds have broken dormancy faster than the ones stored in cold and dry chamber. Changes in alpha-AM and PPO activities are related to alterations in the germination percentage, that is, while the alpha-AM activity increases, PPO activity decreases as dormancy is broken, suggesting these enzymes activities as a promising indicator of dormancy intensity. However, PO and beta-AM activities are not related to dormancy in rice seeds.

Neste estudo foram avaliados diferentes métodos para a superação da dormência em sementes de sucupira-preta. O experimento foi realizado inteiramente ao acaso em esquema fatorial 3 x 7, correspondendo a três lotes de sementes e sete tratamentos, com 4 repetições de 25 sementes. Foram utilizados ácido sulfúrico por 4, 8 e 12 minutos, água a 80°C por 5 e 10 minutos, escarificação mecânica, mantendo-se uma testemunha. Foi observado que a espécie possui dormência tegumentar e que todos os tratamentos utilizados permitiram a entrada de água nas sementes. Contudo, alguns métodos estudados, como a água a 80°C por 10 minutos, resultou em um elevado número de sementes mortas. O método mais eficiente para a superação da dormência de sementes de sucupira-preta é a imersão em ácido sulfúrico, por 4, 8 ou 12 minutos, beneficiando a porcentagem e a velocidade de germinação. This study evaluated diferent methods to overcome dormancy of black sucupira seeds. The experiment was installed in a fully randomized design composed by a factorial scheme 3x7, correspoding to three lots of seeds and seven treatments, with 4 replicates of 25 seeds. Sulfuric acid for 4, 8 and 12 minutes, water at 80°C for 5 and 10 minutes, sandpaper treatments were compared to the control. It was observed that this species has tegument dormancy and all treatments allowed seed imbibition. However in some of the methods used, such as like water at 80°C for 10 minutes, occurred a high number of dead seeds. The most suitable method for dormancy overcoming of black sucupira seeds was the imersion in sulfuric acid for 4, 8 and 12 minutes, that showed higher percentage and speed of germination.

O ponto de colheita interfere na qualidade das sementes, sendo que em especies com frutos carnosos e maturacao desuniforme, existe dificuldade na definicao do mesmo. Objetivou-se avaliar a dormencia em sementes de pimenta malagueta em tres estadios de maturacao durante o armazenamento, visando a determinacao do melhor ponto de colheita e semeadura, e tambem avaliar altera- coes enzimaticas durante o processo de germinacao das sementes processadas em diferentes esta- dios de maturacao, durante o armazenamento. As sementes foram extraidas manualmente de frutos em tres estadios de desenvolvimento: E1 (frutos com primeiros sinais de amarelecimento), E2 (frutos maduros) e E3 (Frutos maduros e submetidos a sete dias de repouso). Apos a secagem as sementes com 8% de teor de agua foram armazenadas em câmara fria por periodos de 0, 4 e 8 meses. Apos estes periodos a qualidade das sementes foi avaliada por meio dos testes de germinacao, vigor e atividades enzimaticas. Para a avaliacao da atividade das enzimas, durante a germinacao das sementes, de cada tratamento, as sementes de cada tratamento foram amostradas, por periodos de 0, 48, 96 e 144 horas apos a semeadura. Empregou-se delineamento de blocos casualizados, em ensaio fatorial 3 epocas de colheita x 3 periodos de armazenamento com quatro repeticoes. Existe dormencia em sementes de pimenta malagueta principalmente quando recem-armazenadas e e superada aos quatro meses de armazenamento. Sementes de pimenta malagueta devem ser colhidas no esta- dio E3 quando forem comercializadas logo apos o processamento e nos estadios E2 ou E3 quando armazenadas por periodos acima de quatro meses. As alteracoes enzimaticas sao evidentes no processo de germinacao e nos diferentes estadios de maturacao durante o armazenamento.

During drying and freezing, protective mechanisms act to maintain seed physiological quality. Some of these mechanisms contribute to the integrity of cell membranes. The damage caused to cell membranes due to cell stress can be seen in ultrastructural studies. The aim of this study was to investigate ultrastructural changes in endosperm cells of coffee seeds brought about by drying and by exposure to low temperatures. Seeds of Coffea Arabica were dried in silica gel to moisture contents of 40, 20, and 5 % (wb) and brought to equilibrium at temperatures of 10, -20, and -86oC. Germination, vigor, and tetrazolium tests were performed for evaluation of seed physiological quality. Ultrastructural damage was analyzed by scanning electron microscopy. Coffee seeds with 40% moisture content have whole, swollen, and expanded cells, with a filled lumen and without signs of damage. The physiological and ultrastructural quality of seeds exposed to below zero temperatures with 40% moisture content is compromised. They have null germination and empty cells, indicating leakage of cell content. Drying of coffee seeds leads to uniform contraction of inner cell content. Drying of coffee seeds to 5% moisture content leads to intense contraction of cell volume, with physiological and ultrastructural damage. Made available in DSpace on 2022-01-18T16:00:40Z (GMT). No. of bitstreams: 1 Ultrastructural-damage-in-coffee-seeds.pdf: 2841205 bytes, checksum: f6e1825a4a770de6f6741d98678d1658 (MD5) Previous issue date: 2020

Post-harvest phases may cause biochemical and physiological changes with direct effects on coffee (Coffea sp.) grains quality during its storage. The aim of this study was to determine the relevance of antioxidant isoenzyme expression on the coffee grains quality undergoing different types of processing and storage conditions. Coffea arabica L. ripe fruits was harvested, part of them was dry processed and another part was wet processing. Immediately, the coffee was dried. After drying, some of the grains were hulled and the other part was maintained unhulled. After that, the grains were stored under refrigerate controlled conditions (10 ºC and 50% relative humidity) or at 25 ºC without relative humidity control for a period of 12 months. Enzymatic expression of catalase, esterase, peroxidase, and alcohol dehydrogenase enzymes was evaluated in the coffee grains in these storage conditions by electrophoretic analysis. The results were compared to the sensorial and physiological profiles of the samples. It was found that expression of enzymes of the antioxidative process is associated with changes in the quality of coffee grains. Natural coffee obtained by dry processing is more sensitive to biochemical changes than wet-processed coffee. A refrigerated environment has a beneficial ffect for preserving the coffee grains showed by higher expression of catalase, peroxidase, and alcohol dehydrogenase enzymes after six months of storage in these conditions. The protection of the endosperm by the presence of the pericarp in natural coffee or the endocarp in fully-washed coffee is beneficial to maintenance of quality and is related to expression of antioxidant enzymes. Made available in DSpace on 2019-05-11T00:37:03Z (GMT). No. of bitstreams: 1 Antioxidantenzymespreservingcoffeequality.pdf: 200287 bytes, checksum: bd0cffc25488c37dff04c27df0269ac4 (MD5) Previous issue date: 2018 Título em espanhol: Enzimas antioxidantes preservan la calidad del café en ambiente refrigerado.

The endo-?-mannanase acts on the hemicellulose fraction of the endosperm cell walls, mainly mannans and galactomannans. This process weakens cell walls and allows radicle protrusion during seed germination, but may also occur during the deterioration process. Thus, the aim of this research was to determine the activity of endo-?-mannanase enzyme in dry coffee seeds and in soaked seeds, evaluating its relationship between physiological qualities. Coffee seeds obtained by different processing methods (natural, fermented and demucilated) and drying (sun, shade and dryer) were used. Seed quality was evaluated by germination and tetrazolium tests, and the endo-?-mannanase enzyme activity was determined in dry seeds and after 10 days of soaking. From the results, it was concluded that there is significant inverse relationship between the physiological quality of coffee seeds and the expression of endo-?-mannanase, and seeds with lower percentages of germination and viability of embryos have a higher activity of the enzyme. After ten days of soaking, coffee seeds had higher expression of endo-?-mannanase as compared to the dry seeds for all treatments of fruit processing and drying. Made available in DSpace on 2017-12-08T23:27:58Z (GMT). No. of bitstreams: 1 RelevanceofendoBmannanase.pdf: 561773 bytes, checksum: da9353a28bfd962f46bcf6ae05000d8d (MD5) Previous issue date: 2017-12-08

Preservation of the quality of coffee seeds is hindered by their intermediate behavior in storage. However, long-term storage at sub zero temperatures may be achieved by adjusting the water content of the seeds. The aim of this study was to evaluate the tolerance of coffee seeds to freezing, in relation to physiological and enzymatic modifications. Coffee seeds were dried in two manners, rapid and slow, to water contents of interest, 0.67, 0.43, 0.25, 0.18, 0.11, and 0.05 g H2O g-¹ dw (dry basis). After drying, the seeds were stored at a temperature of -20 ºC and of 86 ºC for 24 hours and for 12 months, and then compared to seeds in cold storage at 10 ºC. The seeds were evaluated through calculation of percentage of normal seedlings, percentage of seedlings with expanded cotyledonary leaves, dry matter of roots and of hypocotyls, and viability of embryos in the tetrazolium test. Expression of the enzymes superoxide dismutase, catalase, and peroxidase were evaluated by means of electrophoretic analysis. Only seeds dried more slowly to 0.18 g H2O g-1 dw present relative tolerance to storing at -20 °C for 12 months. Coffee seeds do not tolerate storage at a temperature of -86 ºC for 12 months. Water contents below 0.11g H2O g-¹ dw and above 0.43 g H2O g-¹ dw hurt the physiological quality of coffee seeds, regardless of the type of drying, temperature, and storage period. Coffee seed embryos are more tolerant to desiccation and to freezing compared to whole seeds, especially when the seeds are dried to 0.05 g H2O g-¹ dw. The catalase enzyme can be used as a biochemical marker to study tolerance to freezing in coffee seeds. Made available in DSpace on 2017-12-11T23:27:03Z (GMT). No. of bitstreams: 1 ToleranceofCoffeaarabicaL.seeds.pdf: 3225023 bytes, checksum: ea85039e028e6482a3e36e5534e10aaf (MD5) Previous issue date: 2017-12-11 Título em português: Tolerância de sementes de Coffea arabica L. à temperaturas sub zero.

Os efeitos das operações pós-colheita de processamento e secagem e as condições de armazenamento são fatores relevantes a serem considerados para análise da qualidade do café. Dependendo das condições de processamento e secagem, os grãos de café podem sofrer alterações na composição físico-química, influenciando diretamente na qualidade de bebida e consequentemente na avaliação sensorial. Para análise dos resultados, usualmente são utilizadas técnicas de estatísticas univariadas, as quais poderão proporcionar interpretações incoerentes por não considerarem o efeito conjunto entre as variáveis físico-químicas e sensoriais. Assim, objetivou-se propor uma abordagem multivariada dos dados, por meio da combinação de técnicas de componentes principais e gráficos Multi-Vari Chart, que contemple os efeitos das variáveis físico-químicas e sensoriais junto às operações de pós-colheita, na avaliação da qualidade de grãos de cafés. Foram utilizados frutos de Coffea arabica L. cv. Catuaí Amarelo IAC 62 processados para a obtenção de café natural, desmucilado e despolpado. Após o processamento, os cafés foram secados à sombra, ao sol e em secadores mecânicos e foram armazenados por doze meses em câmara fria a 10ºC e 50% UR, sendo avaliados a cada quatro meses. Conclui-se que a utilização da análise de componentes principais em conjunto com a técnica gráfica multivari-chart permite compreender os efeitos conjuntos do processamento, secagem e armazenamento sobre a qualidade química e sensorial do café, bem como suas correlações. Observam-se maiores reduções na pontuação final e maiores valores de condutividade elétrica, durante o armazenamento, nos cafés naturais secados em secador.

A avaliação da cor de grãos de café torna-se importante uma vez que cafés com coloração atípica ou com diferentes níveis de branqueamento receberão menores preços no mercado. Além da desvalorização comercial, a alteração na cor é indicativos da ocorrência de processos oxidativos e alterações bioquímicas que podem modificar os precursores do sabor e aroma dos grãos, reduzindo a qualidade da bebida. Objetivou-se, neste estudo, avaliar as características de cor de grãos de café de diferentes qualidades, os quais foram processados e beneficiados por meio de diferentes métodos, e armazenados em diferentes condições. Frutos de Coffea arabica foram colhidos no estádio cereja e processados, por via úmida e por via seca. Os grãos foram secados até atingirem 11% de teor de água e submetidos a três formas de beneficiamento (manual, mecânico e sem beneficiamento) e a duas condições de armazenamento (10 ºC e 50% de umidade relativa; e 25 ºC sem controle de umidade relativa). Após o armazenamento por oito meses, os parâmetros de cor dos grãos e a qualidade fisiológica e sensorial foram avaliados. A intensidade das cores verde e azul e a luminância dos grãos de café são afetadas pelos métodos de processamento, beneficiamento e condições de armazenamento. Cafés despolpados apresentam coloração verde mais intensa, em comparação aos cafés naturais. O resfriamento do ar de armazenamento de grãos de café a 10ºC propicia menores índices de luminância e da coordenada b, bem como melhor qualidade fisiológica.

O objetivo deste trabalho foi avaliar alterações fisiológicas e bioquímicas em sementes de café submetidas à secagem rápida, em sílica gel, e à secagem lenta, em soluções salinas saturadas. As sementes foram secas até que atingissem os seguintes teores de água: 40, 30, 20, 15, 10 e 5% (base úmida). Após a secagem, uma parte das sementes foi imediatamente avaliada quanto ao desempenho fisiológico e ao perfil de enzimas do processo oxidativo, e outra parte foi avaliada após armazenagem em condição hermética, em câmara fria e seca, por quatro meses. A velocidade de secagem e o teor final de água tiveram efeito significativo sobre a qualidade fisiológica das sementes. Após a secagem rápida em sílica gel, as sementes toleraram teores finais de água mais baixos. No entanto, após a secagem lenta, as sementes com teores finais de água mais elevados apresentaram maior qualidade. O período de armazenamento não afetou a germinação, mas prejudicou o vigor das sementes. A secagem rápida apresenta maior potencial de dano ao endosperma do que aos embriões. O perfil enzimático das sementes de café é afetado pelo teor final de água e pela velocidade de secagem.

Maturity stage and drying method are the factors that most influence coffee seed quality. The objective of this study was to assess the physiological quality and investigate the electrophoretic patterns of catalase and endo-ß-mannanaseenzymes and heat resistant proteins in coffee seeds harvested at different phenological stages and dried under different conditions. Physiological quality was assessed when the seeds had developed the green, greenish-yellow, cherry, overripe and dry stages after three treatments: no drying, conventional drying and fast drying. After each treatment, the physiological quality of the seeds was assessed using the germination test and electrophoretic patterns of heat resistant proteins and the activity of catalase and endo-ß-mannanase enzymes. Seeds harvested at the cherry phenological stage had the best physiological quality, and the drying process reduced quality at the cherry, overripe and dry stages. This reduction was greater under the faster drying process, but at the greenish-yellow stage, seeds had better physiological quality after slow drying. Regarding the results from electrophoretic analysis, endo-ß-mannanase and catalase activities increase as the ripeness stages advance; the activity of endo-ß-mannanase is directly associated with the deterioration process; the expression of heat resistant proteins increases with maturation process and is associated with seed physiological quality. .

In recent research, early stages of coffee seedling development were identified, after radicle protrusion, in which all the essential parts of the seedling can be assessed to demonstrate the potential of seed germination to generate normal plants. Thus, the objective of this research was to develop studies to reduce the time on the germination test. Ten seed lots of coffee were assessed through the germination test, every two days, from the tenth day of sowing, according to the morphological criteria of the seedlings. The data were compared to the standard germination test and analyzed by means of regression analysis and segmented nonlinear regression and planteau response model. It was concluded that the assessment of coffee seedlings at 16 days, in stage S1, provides the similar result of the pattern germination test, allowing a significant reduction of time in order to demonstrate the germination of the seed lots; the seedling assessment coffee in stage S2 does not have reduction of the time for assessing the coffee germination, in relation to the pattern.